Lesion-induced sprouting in the rat dentate gyrus is inhibited by repeated ethanol administration.

The effect of ethanol on hippocampal axonal sprouiting was studied with a histochemical technique for identifying acetylcholinesterase. Unilateral lesion of the entorhinal cortex in adult rats produced an increase in the density of acetylcho-linesterase staining in the outer molecular layer and a concomitant increase in the width of the pale-staining commissural-associational zone of the dentate gyrus. Other rats were given ethanol (11.3 +/- 0.45 grams per kilogram) for 2 weeks before and 9 days after receiving the lesion. Ethanol abolished the expansion of the commissural-associational zone. The effect of ethanol on sprouting axons suggests that it may inhibit recovery of function after brain injury.

Lesion-induced sprouting in the rat dentate gyrus is inhibited by repeated ethanol administration.

The effect of ethanol on hippocampal axonal sprouting was studied with a histochemical technique for identifying acetylcholinesterase. Unilateral lesion of the entorhinal cortex in adult rats produced an increase in the density of acetylcholinesterase staining in the outer molecular layer and a concomitant increase in the width of the pale-staining commissural-associational zone of the dentate gyrus. Other rats were given ethanol (11.3 +/- 0.45 grams per kilogram) for 2 weeks before and 9 days after receiving the lesion. Ethanol abolished the expansion of the commissural-associated zone. The effect of ethanol on sprouting axons suggests that it may inhibit recovery of function after brain injury.

Alcohol's effect on some formal aspects of verbal social communication.

The effects of alcohol on formal aspects of social communication were studied by scoring transcripts of verbal discussions between dyads in alcohol and placebo sessions. At a low dose (3.83 to 1.0 ml/kg), alcohol significantly (P Less than .01) increased the amount of and overlap in communications, and tended to decrease subjects' acknowledgement of their partners' statements. At a high dose (1.5 ml/kg), the rate of overlap in speech was additionally increased, but there was a leveling off or reversal of the drug's effect on amount of communication. The subjects' blood alcohol levels were not related to the drug's effect.

Relationship between neuropsychological performance and alcohol consumption in alcoholics.

Cognitive performance in drug-free alcoholic patients (n = 95) within 7 days of their last drink was significantly predicted by chronic and recent drinking practices. Conceptually distinct cognitive functions were differentially influenced by various combinations of drinking variables. Consideration of curvilinear relationships enhanced the amount of variance explained, and it is suggested that certain patterns of consumption may accelerate the alcohol-induced decline of brain function.

Changes in neuropsychological performance during treatment for alcoholism.

A battery of 24 neuropsychological tests was administered to drug-free alcoholic inpatients (n = 91) within 7 days of their last drink and again 17 days later. Comparisons between this group and a nonalcoholic group of medical inpatients (n = 20) also given the same test battery twice indicated very little improvement due to abstinence (short-term improvement) in the alcoholics after controlling for practice effects. Similarly, when early postwithdrawal performance of the alcoholics was compared to an alcoholic control group (n = 32), which took the test battery only once 21 days after their last drink, little evidence for short-term recovery of cognitive functions was obtained. Insofar as decisions about the initiation of therapeutic treatments which rely on cognitive processes are based on neuropsychological performance, we conclude that such treatments may commence as soon as the clinical symptoms associated with acute withdrawal have subsided.

Cognitive function in asymptomatic HIV infection.

OBJECTIVE: To determine the nature and extent of cognitive deficits in early stage (asymptomatic) human immunodeficiency virus (HIV)-positive homosexual and bisexual men. DESIGN: A cross-sectional design was used to compare 27 HIV-positive, asymptomatic (Centers for Disease Control and Prevention stages 2 and 3) homosexual and bisexual men, who were designated as the seropositive group, with 29 seronegative homosexual and bisexual men, who were designated as the control group. METHODS: The participant groups were closely matched on a number of demographic and lifestyle variables. Participants were carefully and repeatedly screened for substance abuse, a history of psychiatric problems, use of psychoactive medications, and neurological problems. All participants completed an extensive neuropsychological battery and a computerized information processing battery to identify cognitive deficits. RESULTS: No significant between-group differences were found on either the neuropsychological assessments or the information processing tests. Additionally, we found no evidence of a subgroup of seropositive, asymptomatic individuals with general cognitive slowing. CONCLUSIONS: Educated, HIV-positive asymptomatic individuals may show little difference in cognitive performance compared with a group of matched controls when the groups are carefully screened and matched. Additionally, computerized tests may be no more sensitive than neuropsychological tests to cognitive decrements for these types of participants.

Memory facilitation by post-training injection of ethanol.

Immediate post-training IP injection of ethanol (0.75--4.5 g/kg) significantly enhanced retention of a one-trial passive avoidance task in mice compared to saline controls. Ethanol (4.5 g/kg) in the absence of footshock did not affect test performance. The memory facilitation may reflect ethanol's effects on neurotransmitter, macromolecular, or hormonal systems, or a reduction in interference.

Sequence of alcohol presentation is important in the potentiation of long-term events.

Animal and human studies have demonstrated that, depending upon the sequence of alcohol presentation, long-term memory of events can either be enhanced or diminished. In the present study a similar phenomenon is demonstrated in the neuronal excitability of slices of hippocampus from guinea pig brains. Alcohol given after, but not before, 3 days of pentylenetetrazol (PTZ) administration to the intact animal produced kindling equivalent to 5 days of PTZ given by itself. This effect appears to be independent of the known withdrawal effects of alcohol and lasts for at least 14 days after the alcohol and PTZ administration have been discontinued.

Reversal of ethanol intoxications in humans: an assessment of the efficacy of propranolol.

The effect of post-ethanol ingestion of a single dose of propranolol on acute intoxication was studied in 13 healthy male volunteers. A within subjects, double-blind, crossover design was employed. Each subject participated in two experimental sessions. In each session, subjects took a battery of tests under three conditions: Sober, Alcohol (0.8 g/kg) and Alcohol (1.1 g/kg) + Pill, in that order. The pill contained propranolol (40 mg) in one session and placebo in the other. Ethanol significantly reduced motor coordination, memory and divided attention performance and altered mood scores. Propranolol significantly increased ethanol's effects on divided attention, inebriation ratings and the electroencephalogram without significantly altering blood alcohol concentrations. There was no indication that propranolol antagonized any of ethanol's effects. These results agree with studies indicating that ethanol's effects are increased by a reduction in the functional capacity of central catecholamine systems. It is suggested that central catecholamine-stimulating drugs may reverse some of ethanol's effects.

Reversal of ethanol intoxication in humans: an assessment of the efficacy of L-dopa, aminophylline, and ephedrine.

The effect of postethanol treatment with L-Dopa, aminophylline and/or ephedrine was investigated. In one experiment, healthy, male, moderate drinkers ingested ethanol (0.8 g/kg) and then either L-Dopa (1.5 g), or placebo. In a second experiment, subjects ingested ethanol followed by aminophylline (200 mg), ephedrine (50 mg), aminophylline (200 mg) plus ephedrine (50 mg), or placebo. Double-blind, within-subjects, crossover designs were employed. Treatment with L-Dopa significantly reduced ethanol's effect on the electroencephalogram, motor coordination, and divided attention performance (t-test for paired data). Treatment with aminophylline and/or ephedrine also significantly reduced ethanol's effects on the electroencephalogram and motor coordination. The ethanol-antagonism may result from central noradrenergic stimulation.

Retrograde enhancement of human memory with alcohol.

In two experiments with normal male subjects, the ingestion of alcohol (1 ml/kg) immediately after learning significantly improved subsequent remembering. By comparison, marijuana (15 mg) had no significant post-acquisition effect. Facilitation of visual and verbal memory with alcohol under these conditions has implications for the interference and consolidation views of memory.

The alcohol facilitation effect on memory: a dose-response study.

Sixteen normal male subjects participated in four sessions where they studied a set of pictures followed by either placebo, 0.025, 0.50, or 1.0 ml/kg alcohol. Later, when sober, recognition memory was tested. These doses resulted in peak blood alcohol concentrations (BAC) of 0.00, 0.018, 0.034, and 0.067 g/100 ml, respectively. The 1.0 and 0.50 ml/kg doses significantly improved memory for pictures studied before drinking. Alcohol appears to enhance memory directly rather than indirectly via a reduction in interference. It is suggested that a particular phase of the rising blood alcohol curve (0.02-0.03 g/100 ml) facilitates trace consolidation. The facilitating and possibly excitatory effects of alcohol may be important for understanding the rewarding aspects of drinking.

Intact retention in acute alcohol amnesia.

Research on alcohol amnesia has focused on memory processes that are disrupted during intoxication. The present experiment examined the possibility that certain memory processes might be resistant to the amnesic effects of alcohol. Intoxicated and sober subjects studied a list of 29 words. They were then given one of three different retention tests: free recall, identification of degraded words based on the procedure used by Warrington and Weiskrantz (1970), and yes/no recognition. As expected, free recall was significantly impaired by alcohol intoxication. In contrast, in the identification test, intoxicated subjects benefited to the same degree as sober subjects from prior exposure to the items. The two groups did not differ in immediate recognition memory. The results of the free-recall and identification tasks are similar to findings with chronic amnesic patients and suggest that perceptual fluency is not affected by alcohol, whereas elaborative processes supporting recall are particularly sensitive to disruption during intoxication. The failure to find recognition impairment at the level of intoxication used in this study distinguishes temporary alcohol amnesia from chronic amnesia.

Neuropsychological consequences of posttreatment drinking behavior in male alcoholics.

A prospective study was designed to determine the neuropsychological consequences of continued alcohol consumption after treatment for alcoholism. Performance on 24 commonly used clinical neuropsychological tests was examined in 56 male alcoholics approximately 7 months after completion of an inpatient alcoholism treatment program. Abstainers (n = 17) performed better than those who resumed alcohol consumption. Although there was a significant decrease in alcohol consumption, posttreatment drinking behavior still predicted cognitive performance, with increased frequency and quantity per occasion having more deleterious consequences even at consumption levels that are deemed by some to be socially acceptable. It is concluded that alcohol consumption by former alcoholics might serve to maintain cognitive performance at reduced levels, and that this possibility should be considered in determining appropriate treatment goals for alcoholic patients.

Alcohol consumption and cognitive functioning in social drinkers.

Performance by social drinkers on tests of abstracting and adaptive abilities was negatively associated with the amount of alcohol consumed per drinking occasion. The pattern was strongest in heavy drinkers but was also evident in light and moderate drinkers.

Alcohol and the aging process in social drinkers.

Social drinkers' performance on tests of abstracting and concept formation declined significantly as a function of age and of the quantity of alcohol consumed per drinking occasion.

Specifying the relationship between alcohol use and cognitive loss: the effects of frequency of consumption and psychological distress.

Previous research has found a relationship between increased quantity of alcohol usually consumed per drinking occasion and decreased sober cognitive performance. It has been suggested that the effects of quantity of alcohol consumed may be conditional upon the frequency of alcohol use and that decreased performance in social drinkers may be a consequence of psychological distress (i.e., anxiety and depression). An analysis of data from a representative sample of employed men and women in metropolitan Detroit indicates that the relation between quantity of alcohol consumed per occasion and abstraction performance is conditional upon the frequency of alcohol use but that the relationship cannot be accounted for by psychological distress.

An atypical neurocognitive profile in alcoholic fathers and their sons.

Prepubescent boys and their recovering alcoholic fathers exhibited an Atypical Neurocognitive Profile consisting of (1) a reduction in amplitude of the late positive complex (LPC) of the event-related potential (ERP) during a complex visual discrimination task, and (2) reduced visuoperceptual performance evidenced by significantly lower scores on the Object Assembly, Block Design and Picture Completion subtests of the WISC-R and the Embedded Figures Test. Low LPC amplitudes were significantly correlated with poorer visuoperceptual performance. This Atypical Neurocognitive Profile may represent a marker for alcoholism.

Drinking practices and cognitive functioning.

The relationships between drinking practices and cognitive functioning were examined in a non-patient sample. Neither the amount of alcohol consumed over a lifetime nor current frequency of drinking occasions was significantly (ps greater than .05) correlated with cognitive test scores. However, the quantity of alcohol consumed per drinking occasion was inversely related to performance on tests of abstraction, adaptive abilities and concept formation. The results suggest that social drinking may have deleterious effects on cognitive processes.

The impact of fathers' drinking on cognitive loss among social drinkers.

This chapter examines cognitive loss in social drinkers. The question of concern is whether the relationship between increased levels of alcohol consumption and reduced sober cognitive performance is misspecified. In particular, does reduced abstraction performance in social drinkers result from parental heavy drinking rather than, as we have proposed, from social drinkers' current use of alcohol. Because offspring of alcoholics may be at high risk for cognitive deficits even in childhood, these deficits may be transmitted in alcoholic families. Thus, the relationship between increased drinking and sober cognitive loss might be eliminated if parental drinking is controlled. We report here, however, that the effects of current alcohol use on abstraction performance in a representative sample of employed men and women cannot be accounted for by fathers' drinking. Our findings indicate the need for further research on both the cognitive effects of parental drinking and current alcohol use.