Perinatal lead exposure alters locomotion induced by amphetamine analogs in rats
Clifford, P. S., Hart, N., Rothman, R. B., Blough, B., Bratton, G. R., & Wellman, P. J. (2011). Perinatal lead exposure alters locomotion induced by amphetamine analogs in rats. Life Sciences, 88(13-14), 586-589.
Aims: The precise neurochemical perturbations through which perinatal (gestation/lactation) lead exposure modifies the reinforcement efficacy of various psychoactive drugs (e.g., cocaine, opiates) are unknown. The present study considers the role of altered serotonin and dopamine functionality in perinatal lead-psychostimulant interactions. Main methods: Female rats were administered a 16-mg lead or a control solution (p.o.) for 30 days prior to breeding with non-exposed males. Lead exposure was discontinued at weaning (postnatal day [PND] 21). Starting at PND 120, male rats born to control or lead-exposed dams were injected with either PAL-287 or PAL-353, at doses of 0, 2, 4, 8, or 16 umol/kg (i.p.) with each dose given prior to an acute (45 min) locomotion test. Whereas PAL-287 is a potent releaser of serotonin, PAL-353 is not. Each drug induces comparable release of norepinephrine (NE) and of dopamine (DA). Key findings: Control and lead rats exhibited minimal locomotion to PAL-287. PAL-353 produced a dose-dependent activation of locomotion in control rats relative to the effects of PAL-287 in control rats. Lead-exposed rats exhibited a subsensitivity to PAL-353 at doses of 4 and 8 umol/kg. Significance: The subsensitivity of lead rats to PAL-353 is consistent with a lead-induced diminution of dopamine function, an effect noted earlier for the reuptake inhibitor cocaine (Nation et al. 2000). The similar response of lead and control rats to PAL-287 is inconsistent with diminished serotonin function. (c) 2011 Elsevier Inc. All rights reserved