GABA A receptors, also known as γ-aminobutyric acid type A receptors, are a type of ion channel receptor found on the surface of neurons in the central nervous system (CNS). They play a crucial role in inhibitory neurotransmission, which helps maintain the balance and regulation of brain activity, ultimately contributing to the overall function of the CNS.
GABA A receptors are composed of five subunits that come together to form a functional receptor complex. There are several different subunits with various isoforms, leading to great diversity in GABA A receptor subtypes. These subunits can be classified into different families, including alpha, beta, gamma, delta, epsilon, pi, rho, and theta. The combination of subunits and their arrangement within the receptor complex determines the functional properties and pharmacological characteristics of each subtype.
When the neurotransmitter gamma-aminobutyric acid (GABA) binds to GABA A receptors, it opens the ion channel, allowing the flow of negatively charged chloride ions into the neuron. This influx of chloride ions hyperpolarizes the neuron, making it less likely to fire an action potential and reducing overall neuronal activity. This inhibitory effect plays a crucial role in regulating the excitability of neural circuits and maintaining the balance between excitation and inhibition in the brain.
GABA A receptors are the target of various drugs that enhance or modulate GABAergic transmission, such as benzodiazepines, barbiturates, and certain anesthetics. Dysfunctional GABA A receptors have been implicated in numerous neurological disorders, including epilepsy, anxiety, insomnia, and certain types of neurodevelopmental disorders.
