Locomotor activity in rats after administration of nicotinic agonists intracerebrally

Abstract

1 Nicotine (0.13 and 0.4 mg kg⁻¹, s.c.) increased the ambulatory component of locomotor activity in rats previously exposed to the drug. Nicotine did not increase repeated movements reliably. 2 An infusion of either nicotine (8 μg) or the potent nicotinic agonist cytisine (4 μg) into the ventral tegmental area of the forebrain increased ambulation but not repeated movements. 3 An infusion of nicotine or cytisine into the nucleus accumbens, striatum, dorsal hippocampal formation or motor thalamus did not increase ambulatory or repeated movements. 4 Mecamylamine (0.1–1.0 mg kg⁻¹, s.c.) blocked increases in locomotor activity produced by an infusion of nicotine or cytisine into the ventral tegmental area. 5 The locomotor activity produced by systemically administered nicotine may be mediated, in part, through nicotinic receptors located in the ventral tegmental area of the mesolimbic dopamine system.