The repeated intermittent administration of amphetamine (AMP) produces an enduring enhancement in the response of dopamine (DA) systems in the brain to a subsequent "challenge" with amphetamine. However, former amphetamine addicts are not only hypersensitive to amphetamine, but also to "physical or psychological stress". This suggests that sensitization to amphetamine may change the response of...

By increasing dopamine (DA) release and activating feedback mechanisms, amphetamine and related psychostimulants are known to inhibit DA cell firing. Here, we report that D-amphetamine also has an excitatory effect on DA cells, which under control conditions, is masked by the inhibitory effect of D-amphetamine and is revealed when D2-like receptors are blocked. Thus, using in vivo single-unit r...

Behavioral sensitization to psychomotor stimulants has been shown to be accompanied by a number of alterations in the mesoaccumbens dopamine (DA) system, including DA autoreceptor subsensitivity in the ventral tegmental area (VTA), postsynaptic D1 receptor supersensitivity in the nucleus accumbens (NAc), and augmentation of the DA-releasing effects of stimulants in the NAc. The present study ex...

This study examined glucocorticoid-adrenergic interactions in modulating acquisition and memory storage for inhibitory avoidance training. Systemically (s.c.) administered amphetamine (1 mg/kg), but not epinephrine (0.1 mg/kg) or the peripherally acting amphetamine derivative 4-OH amphetamine (2 mg/kg), given to rats shortly before training facilitated acquisition performance in a continuous mu...

The identification of isomeric drugs is gaining increasing importance in forensics and doping control. Isomers vary terms safety, effectiveness, regulation, particularly for amphetamine-related (ARDs). This study developed validated a pseudo-isocratic UPLC-qTOF-MS analytical method the Amphetamine-related (ARDs) blood following mixed-mode solid-phase extraction (MMSPE). procedure requires 250 ?...

The effects on food intake of repeated administration of d-amphetamine and fenfluramine were examined in rats adapted to a 4 hr/day feeding schedule. Control rats given daily injections of amphetamine before food access rapidly developed a partial tolerance to the food intake reducing effect of amphetamine. However, rats given a 6-hydroxydopamine (6-HDA) treatment which produced a large selecti...

Midkine (MK) is a cytokine that modulates amphetamine-induced striatal astrogliosis, suggesting a possible role of MK in neuroinflammation induced by amphetamine. To test this hypothesis, we studied astrogliosis and microglial response induced by amphetamine (10 mg/kg i.p. four times, every 2 h) in different brain areas of MK-/- mice and wild type (WT) mice. We found that amphetamine-induced mi...

We have shown recently that the psychomotor activating effects of amphetamine in the rat are much greater when this drug is administered in association with environmental novelty than when it is given in a home environment. The main purpose of the present study was to explore the neural basis of this phenomenon. We found, using in situ hybridization of c-fos mRNA, that the pattern of neuronal a...

Previous work has shown that individual differences in locomotor activity in an inescapable novel environment can predict acquisition of amphetamine self-administration. The current study examined whether individual differences in approach to novelty in a free choice test could also predict amphetamine self-administration. Further, the current study examined whether individual differences in ei...