Tehrani M H, Barnes E M
Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, TX 77030.
Neurosci Lett. 1988 May 3;87(3):288-92. doi: 10.1016/0304-3940(88)90463-6.
Neuronal cultures of the chick embryo cerebrum were used to study the chronic effects of gamma-aminobutyric acid (GABA) on the expression of the GABA/benzodiazepine receptor complex. A 7 day exposure of developing neurons to 100 microM GABA produced a 70% reduction in the level of [3H]flunitrazepam binding to intact cells, when compared to untreated controls. The reduction was due to a decrease in receptor density (Bmax) rather than the affinity. The same treatment also caused a 75% reduction in the rates of GABA-gated 36Cl- uptake by intact cells, without an effect on the basal (GABA-independent) flux. Eight days after removal of GABA from the medium of treated cultures, the neurons recovered [3H]flunitrazepam binding to levels corresponding to 74% of unexposed, age-matched controls. The results are consistent with a GABA-induced down-regulation of the GABA/benzodiazepine receptor.
