Paleocerebellar stimulation induces in vivo release of endogenously synthesized [3H]dopamine and [3H]norepinephrine from rat caudal dorsomedial nucleus accumbens.
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.
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*
D004298:Dopamine; D009638:Norepinephrine