Final answer:
GABA is an inhibitory neurotransmitter in the CNS that regulates various brain functions. It is involved in muscle action, memory, pain, pleasure, mood, sleep, and learning. GABAergic neurotransmission can occur through various release mechanisms and activates both synaptic and extra-synaptic receptors to control neuronal excitability.
Step-by-step explanation:
GABA (gamma-aminobutyric acid) is the main inhibitory neurotransmitter in the Central Nervous System (CNS). It is synthesized by the enzyme glutamic acid decarboxylase (GAD) and acts as a neurotransmitter to regulate various brain functions. GABAergic neurotransmission is involved in muscle action, memory, pain, pleasure, mood, sleep, and learning.
The release of GABA can occur through exocytosis via synaptic vesicles, leakage through plasma membranes, reversal of plasma membrane GABA transporters, or ion channels in the membranes. GABA can activate both synaptic and extra-synaptic GABAA receptors to generate inhibitory currents, controlling neuronal excitability.
GABA is implicated in various neurological conditions, such as epileptic seizures and schizophrenia, where alterations in GABAergic transmission and excitatory/inhibitory balance are observed.