GABA is a human gene. Variants in GABA have been implicated in Epilepsy, Alzheimer's Disease, Parkinson's Disease. This page covers the gene's normal function, disease associations, expression patterns, and key research findings relevant to neurodegeneration.
GABA transporter 1 (GAT1) is a sodium-dependent GABA transporter that reuptakes GABA from the synaptic cleft back into presynaptic neurons and surrounding glial cells[1]. It belongs to the SLC6A family of neurotransmitter transporters[2] and is the major mechanism for terminating GABAergic signaling.
The SLC6A1 gene encodes GAT1, a membrane protein consisting of 599 amino acids with 12 transmembrane domains[3]. GAT1 utilizes the sodium gradient (and optionally chloride) to transport GABA against its concentration gradient, effectively clearing GABA from the extracellular space within milliseconds of synaptic release.
GAT1 exhibits several key structural features[4]:
The transport cycle involves conformational changes that alternately expose the GABA binding site to the extracellular and intracellular environments. This electrometric transport can generate currents detectable by patch-clamp electrophysiology.
In the brain, GAT1 is expressed primarily on[5][6]:
High expression is observed in the cerebral cortex, hippocampus (CA1-CA3 regions and dentate gyrus), cerebellum (Purkinje cell layer), basal ganglia (striatum and globus pallidus), and brainstem nuclei[5:1].
GAT1 serves several critical functions in neural signaling:
GAT1 deficiency leads to impaired GABA reuptake, resulting in hyperexcitability and seizures[7]. GAT1 knockout mice exhibit spontaneous seizures and increased excitability[7:1]. GAT1 inhibitors (tiagabine) are used as anticonvulsants[8] but can paradoxically cause seizures at high doses.
Altered GABAergic signaling contributes to cognitive deficits in AD[9][10]. GAT1 expression is modified in AD brain tissue, and GAT1 modulators are being explored as therapeutic agents to restore inhibitory-excitatory balance[9:1].
GAT1 modulators may have therapeutic potential for L-DOPA-induced dyskinesias[11]. The basal ganglia GABAergic system is dysregulated in PD, and GAT1 represents a potential therapeutic target[11:1].
Borden et al. GABA transporter heterogeneity (1994). 1994. ↩︎
Gasnier, SLC6A neurotransmitter transporter family (2004). 2004. ↩︎
Richerson & Wu, Sodium-coupled GABA transport (2003). 2003. ↩︎
[Kanner & Schuldiner, GABA transporter structure (2003)](https://doi.org/10.1016/S0092-8674(03). 2003. ↩︎
Conti et al. GAT1 expression in human brain (1999). 1999. ↩︎ ↩︎
Jensen et al. GAT1 knockout mice and epilepsy (2002). 2002. ↩︎ ↩︎
Madsen et al. Tiagabine clinical efficacy (2009). 2009. ↩︎
Melone et al. GAT1 in Alzheimer's disease (2014). 2014. ↩︎ ↩︎
Cherubini & Conti, GABAergic signaling alterations in AD (2001). 2001. ↩︎
Norris & Schaller, GAT1 modulation in Parkinson's disease (2019). 2019. ↩︎ ↩︎