Rats selectively bred for high and low swim-test activity show differential responses to dopaminergic drugs.

摘要: Rationale: Selective breeding of Sprague-Dawley rats has been used to generate a line animals with very low swim-test activity (SwLo) in an attempt model certain characteristics depression. For comparison the SwLo animals, bred for high (SwHi) and non-selectively (SwNS) have generated. Previous studies using these lines suggested inverse relationship between dopamine (DA) function brain inactivity swim test. Objectives: The current experiments investigated possibility that SwHi show differences central DA processes, as by responsiveness agonists. Results: increase ambulation produced d-amphetamine (0.25– 1.0 mg/kg) was largest smallest rats, SwNS showing intermediate response. Amphetamine levels plasma tissue were similar indicating pharmacokinetic not responsible behavioral differences. Repeated amphetamine administration enhancement ambulation-increasing effects this drug (i.e., sensitization), significant seen all three lines. Apomorphine doses stimulate postsynaptic receptors 4.0 mainly increased sniffing behaviors oral suggesting differ proportions D1, D2, D3 receptors. Conclusions: findings suggest differs selectively behavior, feature may make useful studying depressive symptoms might be related function.