Rw. Moyer et Dj. Kennaway, Serotonin depletion decreases light induced c-fos in the rat suprachiasmatic nucleus, NEUROREPORT, 11(5), 2000, pp. 1021-1024
The suprachiasmatic nucleus (SCN) is the locus of the biological clock in m
ammals. Daily light cycles entrain the endogenous circadian rhythms in mamm
als through direct and indirect neural pathways from the retinae to the sup
rachiasmatic nucleus. We have studied the effect of serotonin depletion on
the photic induction of the early response gene c-fos in the SCN of rats. S
erotonin depletion, verified by immunohistochemistry, produced a significan
t decrease (42%) in the number of c-FOS positive cells in the ventrolateral
portion of the SCN. These results support the involvement of serotonin as
a mediator of photic information to the SCN through the retinal projection
to the dorsal raphe nucleus. NeuroReport 11:1021-1024 (C) 2000 Lippincott W
illiams & Wilkins.