Inhibitory synapse

Inhibitory Synapse

An Inhibitory synapse is a type of synapse that reduces the likelihood of the post-synaptic neuron firing an action potential. This is achieved through the release of neurotransmitters that hyperpolarize the post-synaptic neuron, making it more negative and thus less likely to fire an action potential.

Function

The primary function of an inhibitory synapse is to control the firing of the post-synaptic neuron. This is achieved through the release of inhibitory neurotransmitters, such as gamma-aminobutyric acid (GABA) and glycine. These neurotransmitters bind to receptors on the post-synaptic neuron, causing an influx of negatively charged ions into the neuron. This influx of negative ions hyperpolarizes the neuron, making it less likely to fire an action potential.

Structure

Inhibitory synapses are typically located on the cell body or dendrites of the post-synaptic neuron. They are characterized by a narrow synaptic cleft and the presence of inhibitory neurotransmitters. The pre-synaptic neuron releases these neurotransmitters into the synaptic cleft, where they bind to receptors on the post-synaptic neuron.

Role in Neural Circuitry

Inhibitory synapses play a crucial role in shaping the output of neural circuits. They help to balance the excitatory input received by a neuron, preventing it from firing excessively and potentially causing damage. In addition, inhibitory synapses contribute to the generation of rhythmic patterns of activity in neural networks, such as those involved in walking or breathing.

Clinical Significance

Abnormalities in inhibitory synapses have been implicated in a number of neurological and psychiatric disorders, including epilepsy, schizophrenia, and autism. For example, a decrease in inhibitory synaptic transmission can lead to an imbalance between excitation and inhibition, resulting in the hyperexcitability seen in epilepsy.

See Also

• Excitatory synapse
• Neurotransmitter
• Neuron
• Synaptic cleft
• Gamma-aminobutyric acid
• Glycine