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Reduced Serotonergic Immunoreactive Fibers in the Forebrain of Alcohol‐Preferring Rats
Author(s) -
Zhou Feng C.,
Bledsoe Sharon,
Lumeng Larry,
Li TingKai
Publication year - 1994
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/j.1530-0277.1994.tb00912.x
Subject(s) - immunocytochemistry , serotonergic , endocrinology , medicine , hippocampus , forebrain , alcohol , hippocampal formation , chemistry , serotonin , anatomy , biology , central nervous system , biochemistry , receptor
Our previous study indicated that 5‐hydroxytryptamine (5‐HT) immunoreactive fiber densities were decreased in specific areas of the brain in alcohol‐preferring rats (P) when compared with alcohol‐nonpreferring rats (NP). The results of our current study show that there are quantitative and qualitative differences in 5‐HT innervation in other selected regions of the forebrains of P rats. The 5‐HT fiber density in the brains of young adult P and NP rats was measured by immunocytochemistry and quantitative image analysis. A routine error of two‐dimensional quantitation of nerve fiber was addressed and an adjustment was made. The amount of 5‐HT fibers was significantly lower in CA4 and fasciola cinereum of the dorsal hippocampus, caudate‐putamen, and hypothalamus of the P as compared with NP rats (unpaired Student's t tests). In examining the fiber types, we found that, in the frontal cortical and hippocampal regions, where normally fine 5‐HT fibers with small varicosities and thick 5‐HT fibers with large varicosities coexist, fewer fine 5‐HT fibers were seen in P rats as compared with NP rats the fine fibers are known to be vulnerable to abusive drugs. These observations indicate that (a) there are quantitative differences in 5‐HT innervation or that the 5‐HT in some 5‐HT fibers is reduced to a level undetectable by immunocytochemistry, and (b) the fine 5‐HT fibers are specifically reduced to a greater degree in the selected brain regions of P rats when compared with that of NP rats. The involvement of the 5‐HT system in the alcohol abuse is discussed.