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Striatal Ascorbate and its Relationship to Dopamine Receptor Stimulation and Motor Activity
Author(s) -
Zetterström Tyra,
Wheeler David B.,
Boutelle Martyn G.,
Fillenz Marianne
Publication year - 1991
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.1991.tb00029.x
Subject(s) - apomorphine , quinpirole , chemistry , dopamine , agonist , pharmacology , microdialysis , dopamine receptor , dopamine agonist , ascorbic acid , dopaminergic , striatum , endocrinology , medicine , receptor , biochemistry , food science
We have used the techniques of microdialysis and in vivo voltammetry to monitor striatal dopamine and ascorbate, as well as motor activity in unanaesthetized, freely‐moving rats. Systemic administration of the non‐selective dopamine receptor agonist apomorphine (0.5 mg/kg, s.c.) caused a decrease in dopamine, an increase in ascorbate, stereotyped behaviour and a generalized increase in motor activity. Separate systemic applications of the D 2 receptor agonist SKF 38393 (10 mg/kg, s.c.) and the D 2 receptor agonist Quinpirole (0.1 mg/kg s.c.) caused a decrease in dopamine but had no effect on ascorbate or motor activity. After coadministration of these drugs, there was an increase in both ascorbate and motor activity. Local application of apomorphine (0.01 mM) caused a reduction in dopamine similar to that seen following systemic application but had no effect on ascorbate or motor activity. The present results demonstrate that dopamine, via D 1 and D 2 receptors outside the striatum, plays an important role in the control of ascorbate release. These results lend further support to the hypothesis that changes in ascorbate levels are an index of glutamatergic neurotransmission.