Amphetamine use is associated with dysphoric states, including heightened anxiety, that emerge within 24h of withdrawal from the drug. Corticotropin-releasing factor increases serotonin release in the central nucleus of the amygdala, and this neurochemical circuitry may play a role in mediating fear and anxiety states. We have previously shown that chronic amphetamine treatment increases cortic...

Previous research using outbred rats indicates that individual differences in activity in a novel environment predict sensitivity to the reinforcing effect of psychostimulant drugs. The current study examined if the link between responses related to novelty and amphetamine self-administration is heritable. Twelve inbred rat strains were assessed for locomotor activity in a novel environment, pr...

Studies in laboratory rodents suggest that previously neutral stimuli repeatedly paired with the administration of drugs of abuse can acquire the ability to increase striatal dopamine release. This conditioned neurochemical response is believed to prompt drug seeking in animals and has been hypothesized to contribute to drug craving and relapse in substance abusers. In the present study, we use...

Fragments of beta-endorphin and amphetamine cause similar effects in some tests of maze behavior in rats. The present study served to compare the influence of amphetamine and two beta-endorphin fragments [beta-endorphin (beta E)-(2-9) and beta E-(2-16)] on maze behavior in more detail. In Experiment I no significant effects of amphetamine and the peptides on behavioral performance in three sele...

The stimulant drug amphetamine is postulated to enhance dopamine release through the plasmalemmal dopamine transporter by an exchange diffusion with synaptosomal dopamine. Because protein kinase C has been shown to have an effect on dopamine transporter activity, we examined the effect of protein kinase C inhibitors on endogenous dopamine release stimulated by amphetamine in perfused rat striat...

Rationale: Amphetamine abuse by adolescents predicts long-term drug dependence. Heightened vulnerability to drug abuse could be due to higher sensitivity to drug’s reinforcing effects. Rodents are used to study age-related sensitivities to drugs. Objective: We compared intravenous amphetamine self-administration between adolescent and adult male rats on an operant schedule of reinforcement meas...

Previous work in our laboratory has demonstrated a potentiation of the psychomotor effects of amphetamine in animals with a history of sodium depletion, a process referred to as cross-sensitization. The present studies were done to further develop this finding by assessing multiple effects of amphetamine in rats with and without a history of sodium depletion. For Experiments 1-3, rats were depl...

Intraventricular adrenal medulla grafts were found to produce dissociable effects on rotational behavior induced by amphetamine and apomorphine in rats with unilateral striatal dopamine depletions. Some animals showed a decrease in the behavioral response to apomorphine, some showed a decrease to amphetamine, and some showed a decrease to both amphetamine and apomorphine. Using in uiuo microdia...

The effects of acute administration of amphetamine on membrane potentials and evoked postsynaptic potentials of caudate neurons in cats were assessed using intracellular recording. High doses of amphetamine (0.5 mg/kg, i.v.) produced a reversible depolarization of the cell membrane in 78% of cells tested. Low doses (0.1 mg/kg) had no effect on the resting membrane potential. Long-lasting increa...

We report a case of silent acute ST-elevation myocardial infarction associated with amphetamine use in a 62 years old diabetic man. The patient was devoid of chest pain and had a normal cardiac enzyme analysis at the initial presentation. A routine electrocardiogram demonstrated acute inferior wall ST-elevation myocardial infarction. Coronary angiography confirmed a total occlusion of the poste...