Receptors for neurotransmitters are present on post synaptic membrane... see ncert class 11 pg 319-320.

Receptor Sites for Neurotransmitters on Post-Synaptic Membrane

Neurotransmitters are chemical messengers that transmit signals across synapses in the nervous system. The process of neurotransmission involves the release of neurotransmitters from the presynaptic neuron, which then bind to specific receptor sites on the post-synaptic membrane of the target neuron. This binding results in the generation of a signal in the post-synaptic neuron.

Location of Receptor Sites

The receptor sites for neurotransmitters are present on the post-synaptic membrane of the target neuron. These receptor sites are specific for different neurotransmitters and are typically composed of proteins that span the membrane. The binding of a neurotransmitter to its receptor site triggers a series of events that ultimately lead to the generation of a signal in the post-synaptic neuron.

Types of Receptor Sites

There are two main types of receptor sites for neurotransmitters: ionotropic receptors and metabotropic receptors. Ionotropic receptors are ligand-gated ion channels that allow ions to flow into or out of the cell in response to neurotransmitter binding. Metabotropic receptors, on the other hand, are coupled to intracellular signaling pathways that modulate the activity of the target neuron.

Importance of Receptor Sites

The specificity of receptor sites for neurotransmitters is important for the proper functioning of the nervous system. Different neurotransmitters have different effects on the post-synaptic neuron, and the binding of a neurotransmitter to its specific receptor site is necessary for the appropriate response to occur. For example, the binding of acetylcholine to its receptor sites on the post-synaptic membrane of a muscle cell triggers muscle contraction, while the binding of dopamine to its receptor sites in the brain is involved in reward and motivation.

Conclusion

In summary, receptor sites for neurotransmitters are present on the post-synaptic membrane of the target neuron. These receptor sites are specific for different neurotransmitters and are composed of proteins that span the membrane. The binding of a neurotransmitter to its receptor site triggers a series of events that ultimately lead to the generation of a signal in the post-synaptic neuron. The specificity of receptor sites is important for the proper functioning of the nervous system.