LACK OF ALTERED STARTLE RESPONDING IN RATS FOLLOWING TERMINATION OF SELF-ADMINISTERED OR NONCONTINGENTLY INFUSED COCAINE

The effect of cocaine on the acoustic startle response was assessed in rats trained to intravenously self-administer cocaine (0.25 mg/inject ion) and in rats continuously infused through an intraperitoneal cathe ter with up to 170 mg/kg/day of cocaine. Neither a 12-h self-administr ation ''binge'' nor 13 days' continuous infusion produced significant effects on the startle response as compared to controls up to 24 h aft er termination of drug exposure. These findings suggest that prolonged cocaine administration may result in a dependence syndrome dissimilar to that observed with CNS depressant drugs or alcohol.