TABLE 2 .
Characterization of synaptic (αβγ2-containing) and extrasynaptic (αβδ-containing) GABA-A receptors in the brain
| Synaptic GABA-A Receptors |
Extrasynaptic GABA-A Receptors |
|
|---|---|---|
| Subunits | Pentamer (γ2-containing) | Pentamer (δ-containing) |
| Inhibition | Phasic | Tonic |
| GABA affinity | Low | High |
| GABA efficacy | High | Low |
| Desensitization | Pronounced | Moderate/low |
| Benzodiazepines | Sensitive | Insensitive |
| NSs | Potentiated | Highly potentiated |
| Low [Zn2+] blockade | N | Y |
| Distribution | Highly prevalent | Highly specific regional (e.g., hippocampus, neocortex, thalamus, hypothalamus, cerebellum) |