**Answer:**

The pneumotaxic center in rabbits is located in the brainstem, specifically in the pons region of the brain.

**Pons:**

The pons is a part of the brainstem located above the medulla oblongata and below the midbrain. It plays a crucial role in regulating various functions including respiration. The pons contains several important respiratory centers, including the pneumotaxic center.

**Respiration Regulation:**

The regulation of respiration involves a complex interplay between different regions of the brainstem, including the medulla and pons. The medulla contains the primary respiratory centers, while the pons helps to fine-tune and modulate the respiratory rhythm.

**Pneumotaxic Center:**

The pneumotaxic center, also known as the pontine respiratory center or the apneustic center, is a group of neurons located in the pons. It is responsible for regulating the duration and rate of breathing by sending inhibitory signals to the inspiratory centers in the medulla.

**Function:**

The pneumotaxic center plays a crucial role in controlling the transition between inspiration and expiration during respiration. It helps to regulate the depth and frequency of breaths by adjusting the timing of the inspiratory and expiratory phases.

When the pneumotaxic center is activated, it sends inhibitory signals to the inspiratory centers in the medulla. This inhibitory input limits the duration of inspiration, resulting in shorter breaths and increased respiratory rate. On the other hand, when the pneumotaxic center is suppressed, the inspiratory phase is prolonged, leading to deeper breaths and decreased respiratory rate.

**Importance:**

The proper functioning of the pneumotaxic center is important for maintaining efficient respiration. Any disruptions or abnormalities in this center can lead to respiratory disorders and irregular breathing patterns.

In conclusion, the pneumotaxic center in rabbits is located in the brainstem, specifically in the pons region of the brain. It plays a crucial role in regulating the duration and rate of breathing by sending inhibitory signals to the inspiratory centers in the medulla.

For mammals pneumatoxic center present in the pons varoli of hind brain . It can moderate the functions of respiratory rhytm center which is present in the medulla region. The neural signal from this region also decrease the duration of inspiratory and respiratory rate.