Impact of a novel environment on alcohol-induced locomotor activity in Wistar rats

BCI Improves Alcohol-Induced Cognitive and Emotional Impairments by Restoring pERK-BDNF

Binge drinking causes a range of problems especially damage to the nervous system, and the specific neural mechanism of brain loss and behavioral abnormalities caused by which is still unclear. Extracellular regulated protein kinases (ERK) maintain neuronal survival, growth, and regulation of synaptic plasticity by phosphorylating specific transcription factors to regulate expression of brain-derived neurotrophic factor (BDNF). Dual-specific phosphatase 1 (DUSP1) and DUSP6 dephosphorylate tyrosine and serine/threonine residues in ERK1/2 to inactivate them. To investigate the molecular mechanism by which alcohol affects memory and emotion, a chronic intermittent alcohol exposure (CIAE) model was established. The results demonstrated that mice in the CIAE group developed short-term recognition memory impairment and anxiety-like behavior; meanwhile, the expression of DUSP1 and DUSP66 in the mPFC was increased, while the levels of p-ERK and BDNF were decreased. Micro-injection of DUSP1/6 inhibitor BCI into the medial prefrontal cortex (mPFC) restored the dendritic morphology by reversing the activity of ERK-BDNF and ultimately improved cognitive and emotional impairment caused by CIAE. These findings indicate that CIAE inhibits ERK-BDNF by increasing DUSP1/6 in the mPFC that may be associated with cognitive and emotional deficits. Consequently, DUSP1 and DUSP6 appear to be potential targets for the treatment of alcoholic brain disorders.

Effect of intermittent access to alcohol mixed in energy drink during adolescence on alcohol self-administration, anxiety, and memory during adulthood in rats

BACKGROUND

Mixing alcohol with caffeinated energy drinks is a common practice among young people. Consumption of alcohol mixed in energy drink is associated with increased risk of binge drinking and alcohol dependence. The purpose of this study was to determine whether voluntary intermittent access to alcohol mixed in energy drink in adolescent rats alters adult self-administration of alcohol, anxiety, and memory.

METHODS

For 10 weeks in the home-cage, two groups of adolescent female Sprague-Dawley rats had intermittent access to energy drink (ED) or 10% alcohol mixed in energy drink (AmED) with water concurrently available. Other rat groups had daily continuous access to ED or AmED. Anxiety was measured with an open field test and memory was assessed with a novel place recognition test. For self-administration, rats pressed levers for 10% alcohol alone on a fixed ratio (FR1) and on a progressive ratio (PR).

RESULTS

Intermittent access to AmED generated greater intake during the initial 30 min of access (AmED 1.70 ± 0.04 g/kg vs. ED 1.01 ± 0.06 g/kg) and during the subsequent 24 h (AmED 7.04 ± 0.25 g/kg vs. ED 5.60 ± 0.29 g/kg). Intermittent AmED caused a significant but small decrease in anxiety while neither ED nor AmED altered memory. During alcohol self-administration, group differences emerged only during PR testing during which intermittent AmED rats responded more than all other groups.

CONCLUSIONS

These findings suggest that intermittent access to AmED generates binge-like consumption that supports human findings that AmED generates greater alcohol consumption. Furthermore, experience with AmED may alter the motivational properties of alcohol into adulthood without necessarily causing a major impact on anxiety or memory.

Combining ecstasy and ethanol: higher risk for toxicity? A review

Ecstasy use is commonly combined with ethanol consumption. While combination drug use in general is correlated with a higher risk for toxicity, the risk of the specific combination of ecstasy (3,4-methylenedioxymethamphetamine (MDMA)) and ethanol is largely unknown. Therefore, we have reviewed the literature on changes in MDMA pharmacokinetics and pharmacodynamics due to concurrent ethanol exposure in human, animal and in vitro studies. MDMA pharmacokinetics appear unaffected: the MDMA blood concentration after concurrent exposure to MDMA and ethanol was comparable to lone MDMA exposure in multiple human placebo-controlled studies. In contrast, MDMA pharmacodynamics were affected: locomotor activity increased and body temperature decreased after concurrent exposure to MDMA and ethanol compared to lone MDMA exposure. Importantly, these additional ethanol effects were consistently observed in multiple animal studies. Additional ethanol effects have also been reported on other pharmacodynamic aspects, but are inconclusive due to a low number of studies or due to inconsistent findings. These investigated pharmacodynamic aspects include monoamine brain concentrations, neurological (psychomotor function, memory, anxiety, reinforcing properties), cardiovascular, liver and endocrine effects. Although only a single or a few studies were available investigating these aspects, most studies indicated an aggravation of MDMA-induced effects upon concurrent ethanol exposure. In summary, concurrent ethanol exposure appears to increase the risk for MDMA toxicity. Increased toxicity is due to an aggravation of MDMA pharmacodynamics, while MDMA pharmacokinetics is largely unaffected. Although a significant attenuation of the MDMA-induced increase of body temperature was observed in animal studies, its relevance for human exposure remains unclear.