title: Paleocerebellar stimulation induces in vivo release of endogenously synthesized [3H]dopamine and [3H]norepinephrine from rat caudal dorsomedial nucleus accumbens.
abstract: The influence of cerebellar vermis stimulation on noradrenergic and dopaminergic activity in the nucleus accumbens was investigated in anesthetised rat. Artificial cerebral spinal fluid containing [3H]tyrosine was continuously circulated through a unilateral push-pull cannula implanted in the nucleus accumbens. Fifteen-minute perfusate samples were collected serially for three consecutive 1-h periods designated pre-, during-, and post-stimulation. The stimulation was applied through a bilateral electrode located subdurally over the fifth vermal lobe. The [3H]norepinephrine and [3H]dopamine components in each sample were isolated by alumina extraction and high-pressure liquid chromatographic fractionation, and then quantified by liquid scintillation counting. For cannula locations in the caudal dorsomedial nucleus accumbens, levels of both [3H]catecholamines were found to be significantly higher during stimulation compared to the prestimulation baselines, and [3H]norepinephrine remained significantly elevated through the post-stimulation period. The relative increase during stimulation for [3H]norepinephrine (130%) was nearly twice that for [3H]dopamine (70%). These results indicate that vermal activation can significantly raise both noradrenergic and dopaminergic in vivo activity in the caudal dorsomedial nucleus accumbens, and provide a possible mechanism for explaining previously demonstrated influences of paleocerebellum upon affective components of behavior.
mesh_terms: D000818:Animals; D001931:Brain Mapping; D002529:Cerebellar Nuclei / Q000502:physiology; D002531:Cerebellum / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism*; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D009638:Norepinephrine / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000378:metabolism*; D011689:Purkinje Cells / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012686:Septal Nuclei / Q000378:metabolism*
chemical_list: D004298:Dopamine; D009638:Norepinephrine