The neurodynamic effect of graded hydrocortisone treatment on rhinencephalic and telencephalic brain regions was studied in an experimental animal design that sampled isolated hippocampal, basal nucleic and frontal cortical brain regions of male wistar rats. Four test groups, ii to v were administered 2.5 mg, 5 mg, 7.5 mg and 10 mg respectively. The study period lasted for 6 weeks. Results were statistically analyzed and considered significantly different at a confidence interval of 95%. There was a progressive decline in olfactory response as dose of hydrocortisone treatment was increased. There was a significant dose-dependent decrease in assayed frontal cortical acetylcholine and hippocampal glutamate in brain tissue homogenates. Similar change was observed in brain tissue calcium, magnesium and sodium. For the behavioral, histological and biochemical tests conducted in this study, 6 weeks hydrocortisone treatment showed adverse manifestations from 5 mg, which was more obvious from 7.5 mg. The outcome of this study revealed a possible dose-dependent adverse effect of hydrocortisone on specific brain regions responsible for learning, memory, olfaction and psychosocial behavior.