Antagonistic behavioral effects of calcitonin and amphetamine in the rat

Using an automated testing apparatus, the hypermotility induced by amphetamine had previously been found to be inhibited by intracerebroventricular (ICV) administration of salmon calcitonin (CT). The present study used a computer-supported direct observational method to characterize further the interactions of CT and amphetamine. After treatment with amphetamine (1.5 mg/kg, IP), the incidence of rearing, nose poking, and locomotion was reduced in rats that were pretreated with 85 pmol salmon CT ICV; the incidence of sniffing and grooming remained unchanged. CT-induced dyskinesia, a unique consequence of central CT treatment, was attenuated but not abolished by administration of amphetamine. These results support the premise that a compound with receptor recognition characteristics similar to those of salmon CT may act as a neurotransmitter-modulator in the central nervous system.