Differential patterns of regional c-Fos induction in the rat brain by amphetamine and the novel wakefulness-promoting agent modafinil.
We examined the neuronal targets in the rat brain for the novel wakefulness-promoting agent modafinil and for amphetamine using c-Fos immunohistochemistry. Both modafinil and amphetamine induced neuronal expression of c-Fos-like immunoreactivity in the paraventricular nucleus of the hypothalamus, anterior hypothalamus and central nucleus of the amygdala. Modafinil also increased c-Fos-like immunoreactivity in the suprachiasmatic nucleus, while amphetamine had no effect. Brain regions in which amphetamine increased c-Fos-like immunoreactivity, but modafinil had no effect, included frontal cortex, striatum, lateral habenula, supraoptic nucleus and basolateral nucleus of the amygdala. These findings suggest that the mechanism of action of modafinil is different from that of amphetamine and that the neuronal targets for modafinil in the brain include nuclei of the hypothalamus and amygdala.
Engber
T M
TM
Department of Pharmacology, Cephalon Inc., West Chester, PA 19380, USA. tengber@cephalon.com
Koury
E J
EJ
Dennis
S A
SA
Miller
M S
MS
Contreras
P C
PC
Bhat
R V
RV
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001559:Benzhydryl Compounds / Q000494:pharmacology*; D001921:Brain / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D007150:Immunohistochemistry; D008297:Male; D000077408:Modafinil; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014851:Wakefulness
D001559:Benzhydryl Compounds; D000697:Central Nervous System Stimulants; D016760:Proto-Oncogene Proteins c-fos; D000661:Amphetamine; D000077408:Modafinil