At 9 months, while the expression of GABA receptor subunits remained unchanged, the glutamate decarboxylase/GAD (GAD catalyze the conversion of glutamate to GABA) – positive cells are less expressed in the CA1 region of the hippocampus of TgF344-AD rats, indicating impaired GABAergic neurotransmission [73]. The gene discussed is GAD1; the disease is Alzheimer disease.