Increase in Blood Pressure by Local Injection of Ketamine into the Amygdala in Rats

To confirm that an increase in blood pressure induced by ketamine is mediated through the central nervous system, we examined effect of ketamine, applied directly to amygdala, on pressure. Six male Sprague-Dawley rats were used study. Under head-restrained and unanesthetized condition, 0.2 μl (5 mg/ml) was injected around amygdala at a flow rate μl/min glass pipette, recorded while monitoring state animals electroencephalogram electromyogram. After injection, injection site marked Pontamine Sky Blue infusion. Blood increased into basolateral nuclei endopiriform nucleus piriform cortex. In total 11 responses, started with mean latency 193.5 ± 43.0 sec, reached its peak 180.2 23.3 sec after response onset, then gradually returned baseline duration 706.7 113.5 sec. The fluctuation 17.1 2.5 mmHg. We revealed fluctuations are associated amygdala. Elucidation mechanism ketamine-induced will lead understanding side effects contribute appropriate use.