Enduring effects of periadolescent alcohol exposure on passive avoidance performance in rats

Abstract

Rats were administered alcohol during periadolescence (age 30-40 days) and then tested, beginning at 60 days of age, in an aversive-noise passive avoidance task. Relative to a low-dose group and to controls, the animals that had received a high dose were found to be impaired in this task. These results suggest that the developing juvenile is vulnerable to enduring effects of this drug. Thus, risk of impaired development due to alcohol may not be limited to the fetal and neonatal periods but may extend through later postnatal periods as well. Chester F. Bergman constructed the figures. Technical assistance was provided by Janice Hauser, Danny Garland, and Mike Alvis. We thank W. F. Caul and the reviewers for helpful comments on earlier drafts of this paper, Bob Blaszezyk for providing some of the equipment, and M. B. Fletcher for his continued support and encouragement. Correspondence may be sent to G.

The adolescent brain and age-related behavioral manifestations

“…For instance, voluntary ethanol consumption [494] and chronic cocaine exposure [229] during adolescence both were found to significantly increase later aggressive behavior in male Golden hamsters. Chronic exposure of adolescent rodents to alcohol has been reported to induce later alterations in emotionality [474] and cognitive functioning [393] as well as to disrupt pubertyassociated increases in reproductive endocrinology in both males [89] and females [118]. In most cases, it is not clear, however, as to whether exposure during adolescence is critical for these effects or whether similar effects would be evident with comparable drug exposure in adulthood.…”

Adolescent Rats Exposed to Repeated Ethanol Treatment Show Lingering Behavioral Impairments

“…The literature on the effects of adolescent ethanol exposure on subsequent behavior has been inconsistent. Osborne and Butler (1983) administered ethanol to periadolescent rats and studied effects on passive avoidance beginning 20 days after treatment when rats had become adults. Ethanol-treated rats showed impairment in the avoidance task.…”

“…Salimov et al (1996) reported that adolescent ethanolpreferring rats injected with ethanol and tested after an 8-week abstinence period showed less exploratory behavior and greater immobility than ethanol-preferring control rats. Osborne and Butler (1983) treated adolescent rats with a high dose of ethanol (6 g/kg) on alternate days from postnatal day (PD) 30 to PD 40 and tested them in a passive avoidance task starting on PD 60. Rats treated with ethanol had shorter cumulative latencies than the control group, both during training trial and when tested as adults, indicating persistent deficits following adolescent ethanol exposure.…”

Supplemental choline during the periweaning period protects against trace conditioning impairments attributable to post-training ethanol exposure in adolescent rats.

“…However, delay fear conditioning, a non-hippocampal variant of the procedure, was unaffected by post-training ethanol. Binge-like alcohol exposure is known to produce profound changes in hippocampal memory, whether that alcohol exposure occurs during the neonatal period (Goodlett & Johnson, 1997), adolescence (Osborne & Butler, 1983) or adulthood (Obernier, White, Swartzwelder & Crews, 2002). Such exposure can result in changes in cell numbers and densities in hippocampal regions (Bonthius & West, 1990; Crews, Braun, Hoplight, Switzer & Knapp, 2000), as well as changes in hippocampal neurogenesis (Crews, Mdzinarishvili, Kim, He & Nixon, 2006; Hamilton et al, 2011).…”