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The Role of Serotonin in Alcohol’s
Effects on the Brain
Serotonin is an important brain chemical that acts as a neurotransmitterto communicate information among nerve cells. Serotonin’s actions have Department of MolecularPhysiology and Biophysics been linked to alcohol’s effects on the brain and to alcohol abuse. Alcoholics and experimental animals that consume large quantities of alcohol show evidence of differences in brain serotonin levels comparedwith nonalcoholics. Both short- and long-term alcohol exposures alsoaffect the serotonin receptors that convert the chemical signal producedby serotonin into functional changes in the signal-receiving cell.
Drugs that act on these receptors alter alcohol consumption in bothhumans and animals. Serotonin, along with other neurotransmitters,also may contribute to alcohol’s intoxicating and rewarding effects,and abnormalities in the brain’s serotonin system appear to play animportant role in the brain processes underlying alcohol abuse. Serotonin’s Functions
in the Brain
receptors that activateproteins within the cell molecules). Secondmessengers also can act Acute Alcohol Effects on the
on ion channels or travelto the nucleus to alter Brain’s Serotonin Systems
channels. Their activationdirectly excites neurons.
in several ways. Even single-episode(i.e., acute) alcohol exposure altersvarious aspects of serotonin’s synap- Receptor
Potential Role in the
p l e , t h e l eve l s o f se r ot o n in Subtypes
Development of Alcohol Abuse
May control consummatory behavior, including alcohol May contribute to alcohol’s intoxicating effects. May play a role in development of tolerance to alcohol’s effects.
This increase may reflect enhancedsignal transmission at serotonergic May contribute to development of alcohol withdrawal symptoms. May play a role in alcohol’s rewarding effects.
synapses. Animal studies also havefound that acute alcohol exposure May regulate alcohol consumption. May contribute to brain (6,7), suggesting either thatmore serotonin is released from theserotonergic axons or that the neuro- as changes in the cell’s electrical ac- genes (see F1). These changes can
HT2 and 5-HT3 receptors (see T1).
Serotonin’s Role in the
tinuous alcohol-induced alterations.
Development of Alcohol
Serotonin Levels
in Alcoholics
duced serotonin levels in the brain.
assess that receptor’s role in specific f ec ts (1 0 ) . I n t er e st i n g l y, t h e Effects of Chronic Alcohol
Exposure on Serotonergic
Synaptic Transmission
a l c o h o l i n g e s t i o n i n r od en t s Interactions Between
Serotonin and Other
Neurotransmitters
Effects of Serotonin
Uptake Inhibitors
ters also may be affected by alcohol.
Interactions with GABA
tribute to alcohol’s effects on the brain.
d o p a m i n e r e l e a s e ( 26 ) . T h e Interactions with Dopamine
uting to alcohol’s rewarding effects.
appeared in Alcohol Health & Res.
References
P. Griffiths and P.J. Cowen,Psychopharmacol. 112 (1993) 10. J.C. Crabbe, T.J. Phillips, D.J. Feller, , M.B. Sobell, Alcoholism: Clin. andExp. Res. 18 (1994) 879-885.
20. C.A. Naranjo and K.E. Kadlec, Biol.
11. S.C. Pandey, J.M. Davis and G.N.
and F. Weiss, EXS 71 (1994) 103-114.

Source: http://cepolmc.nawigraz.at/user_files/pc-seminary/2007/cs18-1d_serotonin-in-alcohol-affecting-the-brain.pdf