3H-diazepam Binding and Interaction Between GABA and Benzodiazepine Binding Sites in Different Brain Regions of Aged Rats

Abstract

This chapter discusses 3 H-diazepam binding and interaction between γ aminobutyric acid (GABA) and benzodiazepine (BDZ) binding sites in different brain regions of aged rats. A large body of experimental evidence suggests that benzodiazepines in the mammalian central nervous system exert their action by facilitating the synaptic function of GABA. In addition, a functional interaction exists between BDZ and GABA receptors. When BDZ recognition sites of a crude synaptic membrane preparation are occupied, the number of 3 H-GABA high affinity sites is increased and conversely, in the same preparation the stimulation of the GABA binding sites enhances the affinity of BDZ binding sites for their agonists. The chapter discusses the preparation of crude synaptic plasma membrane and 3 H-diazepam binding assay. The kinetic properties of 3 H-Diazepam binding were determined using Scatchard plot analysis of the saturation curves. A progressive increase of 3 H-Diazepam was observed in different brain areas with ageing.