[Effects of bromazepam on cerebral neuronal activity in male Wistar rats with immobilized stress]

The [14C]2-deoxy-D-glucose technique has been applied to examine glucose utilization rate (GUR), as a measure of neuronal activity, of 42 cerebral nuclei, hypophysis and adrenals in male Wistar rats. Restraint and water-immersed stress for a 10 min period significantly increased GUR in the cortex frontalis, nucleus (n.) amygdaloideus centralis and lateralis, n. ventromedialis, substantia nigra, n. reticularis lateralis, n. ambiguus, lobus anterior of hypophysis, and adrenals. The elevation was predominant in the n. amygdaloideus centralis, n. ambiguus and lobus anterior of hypophysis. Bromazepam significantly prevented these elevations at the non-muscle relaxant dose of 1 mg/kg, p.o. Further prolongation (55 min) of stress caused a marked and non-selective increase of GUR in all cerebral nuclei and glands examined. In spontaneously hypertensive rats in the conscious, resting state, the pretreatment with bromazepam (3 mg/kg, p.o.) abolished the stress-induced pressor response and the release of epinephrine, norepinephrine and dopamine beta-hydroxylase into the circulation. These results suggest that the n. amygdaloideus centralis is mostly a sensitive site to stress and one of the major action sites of bromazepam.