Do excitatory and inhibitory conditioning processes underlie psychomotor sensitization to amphetamine? An analysis using simple and multiple regressions.

Excitatory or inhibitory conditioning processes have been proposed to account for the context-dependent establishment of amphetamine psychomotor sensitization in rodents. The purpose of this study was to test the predictions of these theories in mice. We first assessed the consequence of the extinction of post-sensitization conditioned activity (CR) on the ulterior expression of sensitization.

Gender and age at drinking onset affect voluntary alcohol consumption but neither the alcohol deprivation effect nor the response to stress in mice.

Background: Epidemiological studies suggest that initiation of alcohol drinking at an early age is associated with an increased risk of developing an alcohol use disorder later in life. Nevertheless, relatively few studies using animal models have investigated the relationship between age of onset of drinking and ethanol drinking patterns in adulthood. Besides age at drinking onset, other factors such as gender could also affect the pattern of development of alcohol consumption.

Effects of cyanamide and acetaldehyde accumulation on the locomotor stimulant and sedative effects of ethanol in mice.

Ethanol administration induces both locomotor stimulant and sedative effects depending upon blood ethanol concentrations. Recent studies in rats and mice suggest that acetaldehyde, the first product of ethanol metabolism, might be involved in the expression of both the stimulant and the sedative effects of ethanol. A number of studies have used the drug cyanamide in an attempt to clarify the role of acetaldehyde in the behavioral effects of ethanol.

Preclinical and clinical pharmacology of alcohol dependence.

In recent years, advances in neuroscience led to the development of new medications to treat alcohol dependence and especially to prevent alcohol relapse after detoxification. Whereas the earliest medications against alcohol dependence were fortuitously discovered, recently developed drugs are increasingly based on alcohol's neurobiological mechanisms of action. This review discusses the most recent developments in alcohol pharmacotherapy and emphasizes the neurobiological basis of anti-alcohol medications.

Locomotor effects of ethanol and acetaldehyde after peripheral and intraventricular injections in Swiss and C57BL/6J mice.

Several studies have suggested that acetaldehyde, the first product of ethanol metabolism, is involved in the locomotor stimulant effects of ethanol in mice, although it has never been formally tested whether acetaldehyde injected directly into the brain of mice has stimulant properties. Recently, it was also shown in rats that both ethanol and acetaldehyde can induce opposite locomotor effects according to the route of administration. Whereas peripheral administrations of ethanol and acetaldehyde induced locomotor depressant effects, their infusions directly into the brain produced locomotor stimulation.

Dissociation between the locomotor and anxiolytic effects of acetaldehyde in the elevated plus-maze: evidence that acetaldehyde is not involved in the anxiolytic effects of ethanol in mice.

Acetaldehyde, the first product of ethanol metabolism, has been suggested to play a major role in many behavioral effects of ethanol. However, very few studies have directly tested the behavioral effects of the acute administration of acetaldehyde. In particular, the role of this metabolite in ethanol-induced anxiolytic effects has never been extensively tested.

The role of acetaldehyde in the neurobehavioral effects of ethanol: a comprehensive review of animal studies.

Acetaldehyde has long been suggested to be involved in a number of ethanol's pharmacological and behavioral effects, such as its reinforcing, aversive, sedative, amnesic and stimulant properties. However, the role of acetaldehyde in ethanol's effects has been an extremely controversial topic during the past two decades. Opinions ranged from those virtually denying any role for acetaldehyde in ethanol's effects to those who claimed that alcoholism is in fact "acetaldehydism".

The role of acetaldehyde in the central effects of ethanol.

This article represents the proceedings of a symposium at the 2004 annual meeting of the Research Society on Alcoholism in Vancouver, Canada. The symposium was organized by Etienne Quertemont and chaired by Kathleen A. Grant.

Behavioral characterization of acetaldehyde in C57BL/6J mice: locomotor, hypnotic, anxiolytic and amnesic effects.

Rationale: Acetaldehyde, the first metabolite of ethanol, was recently suggested to contribute to many behavioral effects of ethanol, although few studies have directly investigated the behavioral effects of acetaldehyde itself.

Objectives: The aim of the present study was to characterize the locomotor, hypnotic, anxiolytic-like and amnesic effects of acetaldehyde in C57BL/6J mice.

Methods: Increasing doses of acetaldehyde (0-300 mg/kg) were injected intraperitoneally and their effects on a series of representative behaviors were investigated.

The magnitude and the extinction duration of the cocaine-induced conditioned locomotion-activated response are related to the number of cocaine injections paired with the testing context in C57BL/6J mice.

Behavioural activation repeatedly induced by a stimulant in rodents can persist in the absence of the drug if the animals are tested in the context where the drug was previously given, a phenomenon often explained in terms of Pavlovian conditioning. The aim of this study was to verify whether the amplitude of the putative CR (the drug-like activity) increases with the number of the US-CS associations (the number of drug-context pairings), one of the most representative rules of Pavlovian conditioning. The effect of the number of trials on the speed of extinction was also considered.

Sensitised locomotion does not predict conditioned locomotion in cocaine-treated mice: further evidence against the excitatory conditioning model of context-dependent sensitisation.

The excitatory conditioning model of contextual sensitisation proposes that the progressive emergence of the locomotion-activating effect of cocaine (or any other stimulant drug) characterising that phenomenon is due to a growing conditioned response (the test context cues) that mimics the unchanging unconditioned response (the drug effect). The present study aimed at verifying whether the relationship between the amplitude of sensitisation and the size of the conditioned response was positive, a direct implication of that view. Sensitisation to the locomotion-activating effect of cocaine (10 mg/kg, s.

Quasi-asymptotic development of conditioned hyperactivity induced by intermittent injections of cocaine in C57BL/6J mice.

The emergence of a conditioned cocaine-induced hyperlocomotion was examined in C57BL/6J mice using a procedure that has not been used previously. Two days after a session of preexposure to the test chambers under saline, a first group of mice (cocaine-cued) received five once-daily injections of 10-mg/kg s.c.