Abstract
Injections of kappa (k) opioid agonists into the A10 ventral tegmental area (VTA) induce behavioral inhibitions and decreased interest in incentive stimuli, behavioral changes indicative of decreased mesolimbic dopamine (DA) transmission. In seeming contrast, three separate laboratories have recently reported that intra-VTA injections of k agonists do not affect nucleus accumbens septi (NAS) basal levels of extracellular DA. In the present experiment, we investigated whether intra-VTA injections of a k agonist would decrease pharmacologically-stimulated increased levels of extracellular NAS DA. It was found that intra-VTA injections of the k agonist U-50,488H significantly attenuated haloperidol-induced elevations of DA, as measured by in vivo microdialysis.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
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3,4-Dihydroxyphenylacetic Acid / metabolism
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Analgesics / administration & dosage
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Analgesics / pharmacology*
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Animals
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Dialysis
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Dopamine / metabolism*
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Haloperidol / antagonists & inhibitors*
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Haloperidol / pharmacology
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Homovanillic Acid / metabolism
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Hydroxyindoleacetic Acid / metabolism
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Injections, Intraventricular
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Male
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Nucleus Accumbens / drug effects
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Nucleus Accumbens / metabolism*
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Pyrrolidines / administration & dosage
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Pyrrolidines / pharmacology*
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Rats
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Rats, Wistar
Substances
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Analgesics
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Pyrrolidines
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3,4-Dihydroxyphenylacetic Acid
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Hydroxyindoleacetic Acid
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3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
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Haloperidol
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Dopamine
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Homovanillic Acid