N(omega)-nitro-L-arginine methyl ester attenuates lithium-induced c-Fos, but not conditioned taste aversion, in rats.
Lithium chloride (LiCl) at doses sufficient to induce conditioned taste aversion (CTA) causes c-Fos expression in the relevant brain regions and activates the hypothalamic-pituitary-adrenal (HPA) axis. It has been suggested that nitric oxide (NO) in the central nervous system may play a role not only in the activation of HPA axis but also in CTA learning, and that LiCl may activate the brain NO system. To determine the role of NO in lithium-induced CTA, we examined the lithium-induced CTA, brain c-Fos expression, and plasma corticosterone level with Nomega-nitro-L-arginine methyl ester (L-NAME) pretreatment. Intraperitoneal L-NAME (30 mg/kg) given 30 min prior to LiCl significantly decreased lithium-induced c-Fos expression in the brain regions implicated in CTA learning, such as the hypothalamic paraventricular nucleus (PVN), central nucleus of amygdala (CeA), and nucleus tractus of solitarius. However, either the lithium-induced CTA acquisition or the increase in plasma corticosterone was not attenuated by l-NAME pretreatment. These results suggest that NO may be involved in lithium-induced neuronal activation of the brain regions, but not in the CTA acquisition or the HPA axis activation.
Jahng
Jeong Won
JW
Department of Pharmacology, BK21 Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, Korea. jyjahng@yumc.yonsei.ac.kr
Lee
Jong-Ho
JH
Lee
Seoul
S
Lee
Joo Young
JY
Kim
Gun Tae
GT
Houpt
Thomas A
TA
Kim
Dong Goo
DG
D000679:Amygdala / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D003213:Conditioning, Psychological / Q000187:drug effects* / Q000502:physiology; D003345:Corticosterone / Q000097:blood; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000378:metabolism; D007274:Injections, Intraperitoneal; D008094:Lithium / Q000037:antagonists & inhibitors*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D026602:Nitrergic Neurons / Q000187:drug effects* / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017552:Solitary Nucleus / Q000187:drug effects / Q000378:metabolism; D013649:Taste / Q000187:drug effects* / Q000502:physiology
D004791:Enzyme Inhibitors; D016760:Proto-Oncogene Proteins c-fos; D009569:Nitric Oxide; D008094:Lithium; D019331:NG-Nitroarginine Methyl Ester; D003345:Corticosterone