Receptors that bind GABA, the primary inhibitory neurotransmitter. Two primary classes differ in mechanism of action and speed, providing multi-timescale inhibition control.
GABA Receptor
Ionotropic (ligand-gated ion channel). Opens Cl⁻ channels directly upon GABA binding.
Fast process (milliseconds) → rapid hyperpolarization.
GABA receptors handle rapid synaptic transmission—the quick, hard braking that shapes immediate firing patterns and temporal precision in circuits.
GABA Receptor
Metabotropic (G-protein coupled). Activates second messengers that open K⁺ channels.
Slow process (seconds) → prolonged inhibitory potential.
GABA receptors provide slower, longer-lasting inhibition through second messenger cascades, useful for sustained suppression and modulating the gain of neural populations over broader timescales.
Dual System Architecture
The two receptor types create a multi-timescale inhibition system:
- Fast (GABA): Precise temporal control, millisecond-scale circuit coordination
- Slow (GABA): Sustained suppression, population-level gain control
Together, this provides temporal flexibility for fine-tuned coordination and prolonged homeostatic balance.