The interaction between locomotion, striatal dopamine and paramedian reticular nucleus in rats

Abstract

Either intact rats, sham-operated rats, or rats with lesions of the paramedian reticular nucleus (PRN) were exposed to cold (2 degrees C) or heat (36 degrees C) stress and their locomotor activity responses and striatal dopamine (DA) release were compared. At room temperature (22 degrees C), results analyzed revealed significant effects in the PRN-lesioned rats: increases in locomotion (including both horizontal and vertical motion), direction of turnings (including both clockwise and anticlockwise) or striatal DA release. In both the intact rats and the sham-operated rats, either cold or heat stress increased the locomotion, the direction of turnings and the striatal DA release. The increases in both vertical motion and striatal DA release following cold or heat stress were attenuated by PRN lesions. The data suggest that a PRN-striatal DA link existing in rat's brain which affects both the spontaneous and the thermal stress induced locomotor activities.