Vasopressin and noradrenaline coexistence in the rat locus ceruleus: differential decreases of their levels in distant brain areas after thermal and neurotoxic lesions.

Vasopressin (VP) and noradrenaline (NA) coexist in the rat locus ceruleus (LC). After thermal lesions of LC, however, no detectable loss of VP-immunoreactive fibers was examined in the brain. VP and NA levels were also measured in the cortex, hippocampus and cerebellum, after unilateral LC lesions. Only significant ipsilateral depletions of NA levels were found. Therefore, no indications were obtained for VP transport by LC neurons towards distant brain areas.