Masaaki Tagawa1, Michiko Kano1, Nobuyuki Okamura2,
Masatoshi Itoh2, Eiko Sakurai1,
Takehiko Watanabe1 and Kazuhiko Yanai1,*
1Departmentﾊof Pharmacology, Tohoku University School of Medicine,
2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
2Divisionﾊof Nuclear Medicine, Cyclotron and Radioisotope Center,
Tohoku University,
Aramaki Azaaoba, Aoba-ku, Sendai 980-8578, Japan
*ﾊTo whom correspondence should be addressed.
Abstract: Ethanol is a social drug and has been generally known
to be a CNS depressant. A large fluctuation of blood alcohol concentration
(BAC) is well-known to occur due to main factors such as the genetic polymorphism
of the main alcohol metabolizing enzymes and the effect of blood. Few studies
have substantially discussed the relationship between impaired CNS activities
and BAC. In this study, focusing on the correlation of BAC, we investigated
the acute effects of alcohol intake on cognitive performance in humans by
objective evaluation methods consisting of the attention-demanding cognitive
tasks. Tasks were administered to ten healthy male volunteers before and
after ingesting established amounts of alcohol. With increased BAC, we observed
prolongation of reaction time performances and lowering of a coordination
performance. From the results, we concluded that cognitive performance deteriorates
with an increase of BAC. Additionally, the BAC threshold that causes significant
impairment of cognitive performance was estimated to be approximately 50ﾊmg/dl
(ca. 10ﾊmM).
Keywords: Alcohol, Ethanol, Blood alcohol concentration, Cognition, Coordination