Intermittent ethanol binge exposure impairs object recognition but spares contextual and tone fear memory in adolescent rats.

Abstract

Adolescent brain development seems to be important for the maturation of brain structures and behavior. Intermittent binge ethanol drinking is common among adolescents, and this type of drinking can induce brain damage and cognitive deficits. In addition, emotional changes are frequently seen in alcoholics and rodents treated with ethanol. Considering the close relation between emotional arousal and cognitive responses, the present work investigates if intermittent ethanol binge exposure could differentially alter the performance of adolescent rats in aversive and non-aversive motivated tests. Male adolescent rats were submitted to ethanol treatment (2.5 or 5.0 g/Kg, o.a.) at 48-h intervals over postnatal day (PND) 30 to 60. Control animals were exposed to a similar administration protocol with saline administration. At PND61-PND63 animals were submitted to one-trial object recognition or contextual and tone fear conditioning paradigms. Binge ethanol drinking (at both 2.5 and 5.0 g/Kg) did not change freezing response in the contextual and tone fear conditioning. However, all doses impaired recognition rates 24h after training in object recognition test. In addition, despite a diminution of horizontal locomotion in the open field (only for the 5.0 g/Kg dose), no difference was detected regarding time in immobility, time in grooming and number of rearing in this paradigm. The present results show that the cognitive impairment resulting from intermittent binge ethanol exposure has a negative correlation with learning-associated emotional arousal Keyword: ethanol, binge drinking, adolescent rats, learning and memory, emotional arousal.

Adolescent but not adult ethanol binge drinking modulates cocaine withdrawal symptoms in mice

“…In agreement with earlier reports, we observed that our EtOH treatment during adolescence induced both short- (i.e., when measured 5 days after its administration; Study 2) and long-term (i.e., when measured 37 days after its administration; Study 1) memory impairments in the OR task (Figs 3 and 4B respectively) [ 6 , 42 , 55 – 57 ]. In addition, in Study 3 we found the same long-lasting effects when EtOH was given during adulthood ( Fig 5 ).…”

Long‐Lasting Effects of Chronic Intermittent Alcohol Exposure in Adolescent Mice on Object Recognition and Hippocampal Neuronal Activity

“…Impairment of object discrimination had already been shown for short interval in adolescent rats exposed to a CIA (ISI: 1 minute, 3 g/kg, i.p., for 2 consecutive days at 48‐hour intervals over 14 days; Pascual et al., ) or longer interval in adolescent mice (ISI: 1 hour; 2.5, 2.5, and 2 g/kg; i.p., at 2‐hour intervals every 5 days over 15 days; Lacaille et al., ), or rats (ISI: 24 hours; 2.5 or 5 g/kg at 48‐hour intervals over PND 30 to 60; Schaaffhausen et al., ), suggesting deleterious effects of alcohol exposure in adolescence on object recognition performances with both short and long ISI. Discrimination deficits after a shorter retention delay (1 minute) often suggest impairment of encoding.…”