Deleterious Effects of Ethanol, Δ(9)-Tetrahydrocannabinol (THC), and Their Combination on the Spatial Memory and Cognitive Flexibility in Adolescent and Adult Male Rats in the Barnes Maze Task

Abstract

<jats:p>Research demonstrates that adolescents differ from adults in their response to drugs of abuse. The aim of the present study was to examine the influence of ethanol, Δ9-tetrahydrocannabinol hydrochloride (THC), and a combination of these drugs given during adolescence on spatial memory in adolescent and adult rats. Thus, adolescent rats (postnatal day (PND) 30) were subjected to the following groups: 0.9% NaCl; 1.5 g/kg ethanol; 1.0 mg/kg THC; 1.5 g/kg ethanol + 1.0 mg/kg THC. Rats received drug injection four times at three-day intervals. One day after the last injection, half of the treated animals were tested in the Barnes maze task, whereas the remaining animals were tested on PND 70. Results show that there was a significant age effect on spatial memory in the Barnes maze task after these drug administrations. Adolescent animals demonstrated more potent deficits in the spatial learning and memory (probe trial) and in cognitive flexibility (reversal learning) than did adults. However, in adult rats that received these drugs in adolescence, memory decline was observed only after ethanol and ethanol + THC administration. Thus, our results are important in understanding the deleterious impact of THC and/or ethanol abuse during adolescence on memory function across the lifespan (adolescent versus adult).</jats:p>

Rapamycin Improves Spatial Learning Deficits, Vulnerability to Alcohol Addiction and Altered Expression of the GluN2B Subunit of the NMDA Receptor in Adult Rats Exposed to Ethanol during the Neonatal Period

“…The Barnes maze task was conducted as published previously [ 34 , 35 , 36 , 37 , 38 ]. This test consisted of the following phases: adaptation phase (habituation), acquisition phase, test phase (probe trial) and reversal learning.…”

Reversing the Psychiatric Effects of Neurodevelopmental Cannabinoid Exposure: Exploring Pharmacotherapeutic Interventions for Symptom Improvement

“…Similarly, short-term and working memory performances were altered when specific tasks (e.g., novel and spatial object recognition, radial arm maze, T maze, Morris water maze) were carried out in both males and females [59][60][61][62][63]. These THC-induced effects on memory have not been reported consistently among studies [64][65][66][67]. However, the route of administration and dosing regimen of THC used across study protocols, as well as variations in behavioral paradigm techniques may account for such discrepancies.…”

Alcohol Consumption during Adulthood Does Not Impair Later Go/No-Go Reversal Learning in Male Rats

“…Our failure to observe an effect in go/no-go reversal learning adds to the mixed literature on the effects of prior alcohol exposure on reversal learning tasks, with some experiments finding alcohol-induced impairments [9,[11][12][13][14][15][16][17][18][19]35,36] and other experiments finding no impairment (with some experiments even finding an improvement [19][20][21][22][23][24][25]). Differences in the method of alcohol exposure, the dose of alcohol given (and present in the blood), or in the specifics of the reversal task may be responsible for the differing results in the literature and in our current experiment.…”

“…The reinforced and non-reinforced responses are then switched in a second phase. In some rodent models, prior alcohol exposure has impaired both the initial discrimination and the later reversal [9][10][11][12], whereas other experimental conditions found the original discrimination unimpaired and found a selective deficit in reversal learning [9,[13][14][15][16][17][18]. However, many studies have instead found that prior alcohol exposure does not lead to a discrimination or a reversal learning impairment [19][20][21][22][23][24][25].…”