Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: FRIDAY, September 22, 1995 TAG: 9509220100
SECTION: NATIONAL/INTERNATIONAL PAGE: A1 EDITION: METRO
SOURCE: ASSOCIATED PRESS
DATELINE: WASHINGTON LENGTH: Short
Researchers at Columbia-Presbyterian Medical Center in New York have located the cellular mechanism in the brain that is activated by nicotine. The discovery gives new insight into how the tobacco chemical exerts such a powerful influence on the mood, thinking, alertness and addiction of smokers.
Lorna W. Role, senior author of a study to be published today in the journal Science, said nicotine does its work by speeding up and intensifying the flow of glutamate, a neurotransmitter chemical that is a key signal carrier within the brain.
The effect of this faster flow, said Role, ``is like turning up the volume on a radio. It increases the signal. This study gives a better molecular understanding as to why nicotine is such a stimulant.''
Daniel S. McGehee, first author in the study, said the discovery is the initial step toward finding a drug that will block the addictive effects of nicotine and help smokers kick the habit.
Using chicken brain cells kept alive in test tubes, the researchers exposed neurons to extremely small amounts of nicotine and then observed the effects on synaptic transmission, the sending of signals across nerve connections.
McGehee said the nicotine effects were found in the limbic, a key part of the brain that includes ``a reward system'' that encourages some behavior by stimulating neurotransmitter flow.
Role said, ``These pathways in the brain encode information that essentially says, `That was good. Do it again.'"
by CNB