Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter in the central nervous system. Its effects on the post-synaptic cell depend on the type of GABA receptor and the specific context:

 Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter in the central nervous system. Its effects on the post-synaptic cell depend on the type of GABA receptor and the specific context:

GABA-A Receptors:

Activation of GABA-A receptors typically leads to hyperpolarization of the post-synaptic cell.

GABA-A receptors are ligand-gated chloride channels. When GABA binds to these receptors, chloride ions flow into the cell, making the membrane potential more negative (hyperpolarized).

This hyperpolarization reduces the likelihood of action potential firing.

GABA-B Receptors:

Activation of GABA-B receptors can have more complex effects.

GABA-B receptors are metabotropic receptors coupled to G-proteins.

They can lead to hyperpolarization by opening potassium channels, allowing potassium ions to flow out of the cell.

However, they can also modulate other signaling pathways, affecting neuronal excitability in various ways.

Context Matters:

The overall impact of GABA depends on the specific brain region, cell type, and the balance between excitatory and inhibitory inputs.

In some cases, GABA can lead to depolarization due to the reversal potential of chloride ions being close to the resting membrane potential.

For example, during early development, GABA can be excitatory due to the high intracellular chloride concentration.

In summary, GABA can either hyperpolarize or depolarize the post-synaptic cell, depending on the receptor subtype and the cellular context. 🧠💡