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RATIONALE AND OBJECTIVES Footshock stress reliably reinstates heroin seeking in rats, but the time course of the development of this effect following drug withdrawal is not known. Here we studied the effect of intermittent footshock stress on reinstatement of heroin seeking following different withdrawal periods (1-66 days). We also studied whether changes(More)
RATIONALE Behavioral sensitization has been proposed as a process that is important in compulsive drug use and in psychotic disorders. OBJECTIVE The present experiments examine the relationship between behavioral sensitization, induced by either social defeat or amphetamine, and intravenous cocaine self-administration in mice. MATERIALS AND METHODS Male(More)
The impact of ostensibly aversive social stresses on triggering, amplifying and prolonging intensely rewarding drug taking is an apparent contradiction in need of resolution. Social stress encompasses various types of significant life events ranging from maternal separation stress, brief episodes of social confrontations in adolescence and adulthood, to(More)
RATIONALE Intermittent footshock reinstates drug-taking behavior in rats, but not behaviors previously maintained by food reinforcers. Here we tested further the generality of this phenomenon by determining whether restraint and food deprivation stressors would reinstate heroin seeking, whether the environment in which footshock is given modulates(More)
Studies in rats have shown that intermittent footshock stress reinstates drug seeking after prolonged drug-free periods. Recently, we found that another environmental stressor, acute 1 d food deprivation, potently reinstates heroin seeking in rats. Here we report that this effect of food deprivation can be blocked by leptin, a hormone involved in the(More)
Stressful experiences can affect hippocampal structure and function and can suppress new cell birth in the adult hippocampus in several species. Here we examine how repeated intermittent social defeat affects cell proliferation in the dentate gyrus (DG) in mice. Adult male CFW mice were subjected to 10 daily social defeat episodes, 3 defeat episodes within(More)
Alpha-2 adrenoceptor agonists (lofexidine, clonidine) are used to alleviate short-term opioid withdrawal in humans. In rats, acute injections of these agents attenuate stress-induced reinstatement of heroin and cocaine seeking at time points that are beyond the acute drug withdrawal phase. Here, we studied whether exposure to lofexidine would attenuate(More)
RATIONALE Repeated administration of psychostimulants progressively augments the behavioral response to and increases self-administration behavior of these drugs. Experience of repeated intermittent social defeat stress episodes also leads to a sensitized locomotor response following psychostimulant challenge. Both metabotropic and ionotropic glutamate(More)
Stress can trigger, intensify, and prolong drug consumption, as well as reinstate previously extinguished drug-taking behavior by directly impacting a neural circuit often referred to as a reward pathways. Animal models of drug abuse have been used to understand these neural circuits mediating stress-induced drug intake and relapse through examination of(More)
INTRODUCTION Dysregulation of GABAergic inhibition and glutamatergic excitation has been implicated in exaggerated anxiety. Mouse pups emit distress-like ultrasonic vocalizations (USVs) when they are separated from their dam/siblings, and this behavior is reduced by benzodiazepines (BZs) which modulate GABAergic inhibition. The roles of glutamate receptors(More)