Biomedical subjects

T L Wall

Publications and source records attributed to T L Wall.

40 records · Page 3Linked to original sources

PubMedDate not supplied

Rapid induction of tolerance to the antipunishment effects of ethanol.

Tolerance to ethanol was tested with 24 adult, male, Wistar rats using a modified Geller-Seifter paradigm. This design consisted of three components: an unpunished random interval-30 sec (RI-30) schedule, a time-out period, and a punished plus continuous reinforcement (conflict) schedule. This procedure allowed for a distinction to be made between the sedative and the "anxiolytic" effects of ethanol. Rats were trained on this procedure until response rates stabilized. They were then randomly divided into three groups. One group served as a control group for two experiments. In the first experiment, the test group received ethanol (0.75 g/kg IP) on days 2-8 and saline on days 1 and 9. For the second experiment, the control group received saline and the test group received ethanol three times in one day at three hour intervals. The "anxiolytic" action (defined as an increase in the rate of punished responding or antipunishment effect) was observed to undergo rapid tolerance (by day 4 in experiment one and by the second session in experiment two), while tolerance to the sedative action (defined as a decrease in the rate of unpunished responding) developed more slowly (only by day 7 in experiment one, but by the third session in experiment two). These results suggest that rapid tolerance develops to the "anxiolytic" actions of ethanol and this may have important implications for the development of ethanol abuse.

Animals↗

PubMedDate not supplied

Picrotoxinin receptor ligand blocks anti-punishment effects of alcohol.

Ethanol at low doses produces a release of punished responding in an operant rat conflict test similar to that observed for benzodiazepines and phenobarbital. It has been hypothesized that these anti-punishment effects are mediated via the GABA-benzodiazepine receptor-ionophore complex but not at the benzodiazepine binding site. In the present study isopropylbicyclophosphate (IPPO), which binds at the picrotoxinin site, reversed the release of punished responding produced by ethanol, pentobarbital and chlordiazepoxide; at low doses IPPO (less than 10 micrograms/kg) appeared to be most effective against ethanol but at higher doses (greater than 15 micrograms/kg) was also effective against pentobarbital and chlordiazepoxide. At still higher doses IPPO produced a decrease in punished and unpunished responding. These results suggest that the "anxiolytic" actions of ethanol may involve a direct action on the GABA-benzodiazepine receptor-ionophore complex and this action may underlie some of the intoxicating effects of ethanol.

Animals↗

PubMedDate not supplied

EEG alpha activity and personality traits.

Comparisons between EEG spectral power in the fast alpha (9-12 Hz) range and scores obtained on the Millon Clinical Personality Inventory (MCMI) were made in two populations of subjects. The first was a group of 60 individuals who reported no personal or family history of alcoholism. The second was a subgroup of 13 sons of alcoholics and 13 matched control subjects. In the first population, 30% of the subjects were classified as "high" alpha based on the criteria that their EEG in the 9-12 Hz range was over 75 microV2/octave in amplitude. Using this same criteria, 69% of the sons of alcoholics and 31% of their matched controls were also classified as "high" alpha. In both populations, subjects with high amplitude fast frequency EEG alpha activity in lead P4-O2 scored significantly higher on the Histrionic-Gregarious scale of the MCMI than subjects with low amplitude activity in this lead. These results are consistent with some previous studies showing a positive relationship between EEG alpha activity and extroverted personality traits. These results suggest that fast frequency alpha activity may be associated with some definable personality traits.

Adult↗

PubMedDate not supplied

Alcohol dehydrogenase polymorphisms in Native Americans: identification of the ADH2*3 allele.

Alcohol dehydrogenase (ADH) polymorphisms were evaluated among 95 Native American Mission Indians. Approximately equal frequencies of ADH3*1 and ADH3*2 alleles were found. Twelve individuals were heterozygous for ADH2*3, an allele previously identified only in persons of African origin. None of the individuals with ADH2*3 alleles was of purely Native American descent, although none had known African ancestry. These results suggest that these candidate genes deserve broader study among Native Americans and may provide increased understanding of the likely polygenic contributions to alcohol-related disorders in this population.

Alcohol Dehydrogenase↗