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Extraneuronal noradrenaline in the prefrontal cortex of morphine-dependent rats : tolerance and withdrawl mechanism
No full textProfound decrement of mesolimbic dopaminergic neuronal-activity during ethanol withdrawal syndrome in rats - electrophysiological and biochemical-evidence.
No full textActivity of the mesolimbic dopaminergic system was investigated in rats withdrawn from chronic ethanol administration by single-cell extracellular recordings from dopaminergic neurons of the ventrotegmental area, coupled with antidromic identification from the nucleus accumbens, and by microdialysis-technique experiments in the nucleus accumbens. Spontaneous firing rates, spikes per burst, and absolute burst firing but not the number of spontaneously active neurons were found drastically reduced; whereas absolute and relative refractory periods increased in rats withdrawn from chronic ethanol treatment as compared with chronic saline-treated controls. Consistently, dopamine outflow in the nucleus accumbens and its acid metabolites were reduced after abruptly stopping chronic ethanol administration. All these changes, as well as ethanol-withdrawal behavioral signs, were reversed by ethanol administration. This reversal suggests that the abrupt cessation of chronic ethanol administration plays a causal role in the reduction of mesolimbic dopaminergic activity seen in the ethanol-withdrawal syndrome. Results indicate that during the ethanol-withdrawal syndrome the mesolimbic dopaminergic system is tonically reduced in activity, as indexed by electrophysiological and biochemical criteria. Considering the role of the mesolimbic dopaminergic system in the reinforcing properties of ethanol, the depressed activity of this system during the ethanol-withdrawal syndrome may be relevant to the dysphoric state associated with ethanol withdrawal in humans
A tryptophan-free diet markedly reduces frontocortical 5-HT release, but fails to modify ethanol preference in alcohol-preferring (sP) and non-preferring (sNP) rats
No full textMARKED DECREASE OF A10-DOPAMINE NEURONAL FIRING DURING ETHANOL WITHDRAWAL SYNDROME IN RATS
No full textReciprocal antagonism between ACTH 1-24 and b-endorphin in rats
No full textACTH1-24 and beta-endorphin simultaneously injected at 5-10 microgram dose into the lateral ventricle, reciprocally suppress most of their respective behavioural effects (stretching-yawning syndrome, sexual excitement and hyperalgesia for ACTH1-24 and catalepsy and analgesia for beta-endorphin). The results obtained support the hypothesis that ACTH1-24 and beta-endorphin might interact antagonistically at CNS level
Dramatic depletion of mesolimbic extracellular dopamine after withdrawal from morphine, alcohol or cocaine: a common neurochemical substrate for drug dependence
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