Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitterandrsquo;s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be andldquo;dreaming while awake.andrdquo; The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?a)Research into the drug is promising but inconclusive.b)The neuron receptor sites that normally bind serotonin will also bind the drug.c)The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.d)The drug stimulates norepinephrine and serotonin.e)A person who ingests more than 20 micrograms of the drug will have hallucinations.Correct answer is option 'B'. Can you explain this answer?

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Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.
Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.
Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.
Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.
LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.
Q.
According to the passage, which of the following is true of the drug lysergic acid diethlyamide?

a)
Research into the drug is promising but inconclusive.
b)
The neuron receptor sites that normally bind serotonin will also bind the drug.
c)
The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.
d)
The drug stimulates norepinephrine and serotonin.
e)
A person who ingests more than 20 micrograms of the drug will have hallucinations.

Correct answer is option 'B'. Can you explain this answer?

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Scientific advances in the latter half of the twentieth century have a...

Paragraph three is about the effects of and research results on lysergic acid diethlyamide, or LSD.
(A) The passage describes research into Jacob's theory as "promising but inconclusive," but does not make this statement about the drug LSD itself.
(B) CORRECT. The second sentence of the third paragraph says that "LSD mimics serotonin well enough to... bind at most of [serotonin's] receptor sites."
(C) The passage says that the drug causes the locus ceruleus to accelerate activity, the opposite of the causation suggested by this choice – that the locus ceruleus affects the body’s response to the drug.
(D) The passage states that the drug stimulates norepinephrine but inhibits serotonin.
(E) The passage says that "at doses higher than 20 micrograms, it can have a hallucinogenic effect." This means that some people may have hallucinations, but it does not mean that everyone will, as this answer choice suggests.

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Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, all of the following are true EXCEPT

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Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.Which of the following best represents the author’s primary goal in writing the passage?

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Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.Which of the following, if true, would most undermine the central premise of the Jacobs hypothesis?

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Directions: Read the Passage carefully and answer the question as follow.Caffeine, the stimulant in coffee, has been called“the most widely used psychoactive substance on Earth .”Synder, Daly and Bruns have recently proposed thatcaffeine affects behavior by countering the activity in(5) the human brain of a naturally occurring chemical calledadenosine. Adenosine normally depresses neuron firingin many areas of the brain. It apparently does this byinhibiting the release of neurotransmitters, chemicalsthat carry nerve impulses from one neuron to the next.(10) Like many other agents that affect neuron firing,adenosine must first bind to specific receptors onneuronal membranes. There are at least two classesof these receptors, which have been designated A1 andA2. Snyder et al propose that caffeine, which is struc-(15) turally similar to adenosine, is able to bind to both typesof receptors, which prevents adenosine from attachingthere and allows the neurons to fire more readily thanthey otherwise would.For many years, caffeine’s effects have been attri-(20) buted to its inhibition of the production of phosphodi-esterase, an enzyme that breaks down the chemicalcalled cyclic AMP.A number of neurotransmitters exerttheir effects by first increasing cyclic AMP concentra-tions in target neurons. Therefore, prolonged periods at(25) the elevated concentrations, as might be brought aboutby a phosphodiesterase inhibitor, could lead to a greateramount of neuron firing and, consequently, to behav-ioral stimulation. But Snyder et al point out that thecaffeine concentrations needed to inhibit the production(30) of phosphodiesterase in the brain are much higher thanthose that produce stimulation. Moreover, other com-pounds that block phosphodiesterase’s activity are notstimulants.To buttress their case that caffeine acts instead by pre-(35) venting adenosine binding, Snyder et al compared thestimulatory effects of a series of caffeine derivatives withtheir ability to dislodge adenosine from its receptors inthe brains of mice. “In general,” they reported, “theability of the compounds to compete at the receptors(40) correlates with their ability to stimulate locomotion inthe mouse; i.e., the higher their capacity to bind at thereceptors, the higher their ability to stimulate locomo-tion.” Theophylline, a close structural relative of caffeineand the major stimulant in tea, was one of the most(45) effective compounds in both regards.There were some apparent exceptions to the generalcorrelation observed between adenosine-receptor bindingand stimulation. One of these was a compound called3-isobuty1-1-methylxanthine(IBMX), which bound very(50) well but actually depressed mouse locomotion. Snyderet al suggest that this is not a major stumbling block totheir hypothesis. The problem is that the compound hasmixed effects in the brain, a not unusual occurrence withpsychoactive drugs. Even caffeine, which is generally(55) known only for its stimulatory effects, displays thisproperty, depressing mouse locomotion at very low concentrations and stimulating it at higher ones.Q.According so Snyder et al, caffeine differs from adenosine in that caffeine

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Directions: Read the Passage carefully and answer the question as follow.Caffeine, the stimulant in coffee, has been called“the most widely used psychoactive substance on Earth .”Synder, Daly and Bruns have recently proposed thatcaffeine affects behavior by countering the activity in(5) the human brain of a naturally occurring chemical calledadenosine. Adenosine normally depresses neuron firingin many areas of the brain. It apparently does this byinhibiting the release of neurotransmitters, chemicalsthat carry nerve impulses from one neuron to the next.(10) Like many other agents that affect neuron firing,adenosine must first bind to specific receptors onneuronal membranes. There are at least two classesof these receptors, which have been designated A1 andA2. Snyder et al propose that caffeine, which is struc-(15) turally similar to adenosine, is able to bind to both typesof receptors, which prevents adenosine from attachingthere and allows the neurons to fire more readily thanthey otherwise would.For many years, caffeine’s effects have been attri-(20) buted to its inhibition of the production of phosphodi-esterase, an enzyme that breaks down the chemicalcalled cyclic AMP.A number of neurotransmitters exerttheir effects by first increasing cyclic AMP concentra-tions in target neurons. Therefore, prolonged periods at(25) the elevated concentrations, as might be brought aboutby a phosphodiesterase inhibitor, could lead to a greateramount of neuron firing and, consequently, to behav-ioral stimulation. But Snyder et al point out that thecaffeine concentrations needed to inhibit the production(30) of phosphodiesterase in the brain are much higher thanthose that produce stimulation. Moreover, other com-pounds that block phosphodiesterase’s activity are notstimulants.To buttress their case that caffeine acts instead by pre-(35) venting adenosine binding, Snyder et al compared thestimulatory effects of a series of caffeine derivatives withtheir ability to dislodge adenosine from its receptors inthe brains of mice. “In general,” they reported, “theability of the compounds to compete at the receptors(40) correlates with their ability to stimulate locomotion inthe mouse; i.e., the higher their capacity to bind at thereceptors, the higher their ability to stimulate locomo-tion.” Theophylline, a close structural relative of caffeineand the major stimulant in tea, was one of the most(45) effective compounds in both regards.There were some apparent exceptions to the generalcorrelation observed between adenosine-receptor bindingand stimulation. One of these was a compound called3-isobuty1-1-methylxanthine(IBMX), which bound very(50) well but actually depressed mouse locomotion. Snyderet al suggest that this is not a major stumbling block totheir hypothesis. The problem is that the compound hasmixed effects in the brain, a not unusual occurrence withpsychoactive drugs. Even caffeine, which is generally(55) known only for its stimulatory effects, displays thisproperty, depressing mouse locomotion at very low concentrations and stimulating it at higher ones.Q.The primary purpose of the passage is to

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Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?a)Research into the drug is promising but inconclusive.b)The neuron receptor sites that normally bind serotonin will also bind the drug.c)The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.d)The drug stimulates norepinephrine and serotonin.e)A person who ingests more than 20 micrograms of the drug will have hallucinations.Correct answer is option 'B'. Can you explain this answer?

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Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?a)Research into the drug is promising but inconclusive.b)The neuron receptor sites that normally bind serotonin will also bind the drug.c)The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.d)The drug stimulates norepinephrine and serotonin.e)A person who ingests more than 20 micrograms of the drug will have hallucinations.Correct answer is option 'B'. Can you explain this answer? for GMAT 2024 is part of GMAT preparation. The Question and answers have been prepared according to the GMAT exam syllabus. Information about Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?a)Research into the drug is promising but inconclusive.b)The neuron receptor sites that normally bind serotonin will also bind the drug.c)The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.d)The drug stimulates norepinephrine and serotonin.e)A person who ingests more than 20 micrograms of the drug will have hallucinations.Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for GMAT 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?a)Research into the drug is promising but inconclusive.b)The neuron receptor sites that normally bind serotonin will also bind the drug.c)The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.d)The drug stimulates norepinephrine and serotonin.e)A person who ingests more than 20 micrograms of the drug will have hallucinations.Correct answer is option 'B'. Can you explain this answer?.

Solutions for Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?a)Research into the drug is promising but inconclusive.b)The neuron receptor sites that normally bind serotonin will also bind the drug.c)The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.d)The drug stimulates norepinephrine and serotonin.e)A person who ingests more than 20 micrograms of the drug will have hallucinations.Correct answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for GMAT. Download more important topics, notes, lectures and mock test series for GMAT Exam by signing up for free.

Here you can find the meaning of Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?a)Research into the drug is promising but inconclusive.b)The neuron receptor sites that normally bind serotonin will also bind the drug.c)The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.d)The drug stimulates norepinephrine and serotonin.e)A person who ingests more than 20 micrograms of the drug will have hallucinations.Correct answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?a)Research into the drug is promising but inconclusive.b)The neuron receptor sites that normally bind serotonin will also bind the drug.c)The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.d)The drug stimulates norepinephrine and serotonin.e)A person who ingests more than 20 micrograms of the drug will have hallucinations.Correct answer is option 'B'. Can you explain this answer?, a detailed solution for Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?a)Research into the drug is promising but inconclusive.b)The neuron receptor sites that normally bind serotonin will also bind the drug.c)The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.d)The drug stimulates norepinephrine and serotonin.e)A person who ingests more than 20 micrograms of the drug will have hallucinations.Correct answer is option 'B'. Can you explain this answer? has been provided alongside types of Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?a)Research into the drug is promising but inconclusive.b)The neuron receptor sites that normally bind serotonin will also bind the drug.c)The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.d)The drug stimulates norepinephrine and serotonin.e)A person who ingests more than 20 micrograms of the drug will have hallucinations.Correct answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus.Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect.LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be “dreaming while awake.” The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?a)Research into the drug is promising but inconclusive.b)The neuron receptor sites that normally bind serotonin will also bind the drug.c)The locus ceruleus causes the drug to affect bodily systems more rapidly than normal.d)The drug stimulates norepinephrine and serotonin.e)A person who ingests more than 20 micrograms of the drug will have hallucinations.Correct answer is option 'B'. Can you explain this answer? tests, examples and also practice GMAT tests.

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