Repeated administration of psychostimulants such as cocaine leads to the development of behavioral sensitization. Extracellular signal-Regulated Kinase (ERK), an enzyme important for long-term neuronal plasticity, has been implicated in such effects of these drugs. Although the nucleus accumbens (NAcc) is the site mediating the expression of behavioral sensitization by drugs of abuse, the preci...

Cocaine was administered daily (15 mg/kg, i.p. x 1 d followed by 30 mg/kg, i.p. x 5 d) to produce behavioral sensitization. Using microdialysis in the ventral tegmental area and medial substantia nigra, the effect of repeated cocaine was examined on the extracellular levels of dopamine. One day after discontinuing repeated cocaine injections, an acute challenge with cocaine (15 mg/kg, i.p.) pro...

The Synergistic Effects of Methylphenidate on the Behavioral Effects of Nicotine by Kristen K. Leedy One of the most common childhood disorders, attention-deficit hyperactivity disorder (ADHD) places individuals at a higher risk for nicotine (NIC) dependence. Approximately 37.2% of individuals with ADHD currently smoke compared to the 18.3% of individuals with no record of mental illness. Methy...

The prevalence of smoking in schizophrenia patients far exceeds that in the general population. Increased vulnerability to nicotine and other drug addictions in schizophrenia may reflect the impact of developmental limbic abnormalities on cortical-striatal mediation of behavioral changes associated with drug use. Rats with neonatal ventral hippocampal lesions (NVHLs), a neurodevelopmental model...

Some people who repeatedly use stimulant drugs, such as amphetamine (AMPH), develop an AMPH-induced psychosis that is similar to paranoid schizophrenia. There has been, therefore, considerable interest in characterizing the effects of chronic stimulant drug treatment on brain and behavior in non-human animals, and in developing an animal model of AMPH psychosis. A review of this literature show...

Repeated administration of haloperidol (HAL) and olanzapine (OLZ) causes a progressively enhanced disruption of the conditioned avoidance response (CAR) and a progressively enhanced inhibition of phencyclidine (PCP)-induced hyperlocomotion in rats (termed antipsychotic sensitization). Both actions are thought to reflect intrinsic antipsychotic activity. The present study examined the extent to ...

BACKGROUND The N-methyl-D-aspartate (NMDA) receptors play a role in behavioral abnormalities observed after administration of the psychostimulant, methamphetamine (METH). Serine racemase (SRR) is an enzyme which synthesizes D-serine, an endogenous co-agonist of NMDA receptors. Using Srr knock-out (KO) mice, we investigated the role of SRR on METH-induced behavioral abnormalities in mice. METH...

These experiments were designed to assess the role of neurotrophins and the Ras/mitogen-activated protein kinase (MAP) signal transduction cascade in behavioral sensitization to cocaine. The first experiments evaluated the effect of three daily intra-ventral tegmental area (VTA) microinjections of neurotrophin-3 (NT-3) or brain-derived neurotrophic factor (BDNF) on the behavioral-activating eff...

Several lines of evidence indicate that the use of stimulant drugs, including methylphenidate (MPD), increases tobacco smoking. This has raised concerns that MPD use during adolescence could facilitate nicotine abuse. Preclinical studies have shown that repeated treatment with an addictive drug produces sensitization to that drug and usually cross-sensitization to other drugs. Behavioral sensit...

Conditioned place preference (CPP) is a model to study the role of drug conditioning properties. In outbred strains, individual variability may affect some behavioral measures. However, there are few studies focusing on understanding how different phenotypes of ethanol conditioned behavior may influence its extinction, reinstatement, and behavioral adaptation measures. We used male Swiss Webste...