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Ethanol (EtOH), the main psychoactive ingredient of alcoholic drinks, is widely considered to be responsible for alcohol abuse and alcoholism through its positive motivational properties, which depend, at least partially, on the activation of the mesolimbic dopaminergic system. However, acetaldehyde (ACD), the first metabolite of EtOH, has been classically(More)
The intravenous administration of the psychoactive constituent of marijuana, delta9-tetrahydrocannabinol (delta9-THC) (62.5-1000 microg/kg), and the synthetic cannabinoid agonist WIN 55212,2 (WIN) (62.5-500 microg/kg), produced a dose-related increase in the firing rate and burst firing in the majority of antidromically identified meso-prefrontal(More)
The spontaneous neuronal activity of meso-accumbens dopaminergic neurons was recorded in unanesthetized rats withdrawn from chronic morphine administration (15 days) by means of single cell extracellular recording techniques coupled with antidromic identification from the nucleus accumbens. Twenty-four h after last morphine administration, firing rate and(More)
Acetaldehyde (ACD) has been postulated to mediate some of the neurobehavioral effects of ethanol (EtOH). In this study we sought to evaluate whether the stimulatory effects of EtOH on mesolimbic dopamine (DA) transmission are affected by the administration of ACD-sequestering agent D-penicillamine (Dp). To this end we studied the effect of EtOH and ACD in(More)
The present study was designed to determine if cannabinoids share with other drugs of abuse the ability to stimulate mesolimbic dopaminergic neurons and if this effect is mediated by cannabinoid receptors. To this end, the effects of the prototypical cannabinoid, delta9 tetrahydrocannabinol ¿(-)-trans-(6aR,10aR)-6a,7,8,10a-tetrahydro-6,6,9-trimethyl-(More)
Depolarization-induced suppression of inhibition (DSI) and depolarization-induced suppression of excitation (DSE) are two related forms of short-term synaptic plasticity of GABAergic and glutamatergic transmission, respectively. They are induced by calcium concentration increases in postsynaptic cells and are mediated by the release of a retrograde(More)
The mesolimbic dopamine system has recently been implicated in the long-term aversive consequences of withdrawal from major drugs of abuse. In the present study we sought to determine whether mesolimbic dopamine neurons are involved in the neurobiologic mechanisms underlying withdrawal from chronic cannabinoid exposure. Rats were treated chronically with(More)
Morphine withdrawal is characterized by functional alterations at the level of the ventrotegmental area. We investigated the effects of chronic morphine administration and withdrawal on the morphological properties of immuno-labelled tyrosine hydroxylase-positive neurons of the rat ventrotegmental area with a confocal laser scanning microscope.(More)
The activity of mesolimbic dopaminergic neurons was investigated in rats at various times after a chronic regimen of morphine, which produced, upon suspension, a marked somatic withdrawal syndrome. Single-cell extracellular recording techniques, coupled with antidromic identification from the nucleus accumbens, were used to monitor neuronal activity while(More)
Withdrawal of rats from chronic ethanol (2-5 g/kg, every 6 hr for 6 days) resulted in withdrawal symptomatology and dramatic fall in extracellular dopamine (DA) in the ventral striatum as measured by microdialysis. The changes in DA output paralleled the withdrawal symptomatology and both phenomena were reversed by a challenge ethanol dose (5 g/kg orally).(More)