TY - JOUR
T1 - Involvement of 5-HT(1A) receptor mechanisms in the inhibitory effects of methamphetamine on photic responses in the rodent suprachiasmatic nucleus
AU - Moriya, Takahiro
AU - Yamanouchi, Shiro
AU - Fukushima, Tatsuto
AU - Shimazoe, Takao
AU - Shibata, Shigenobu
AU - Watanabe, Shigenori
PY - 1996/11/18
Y1 - 1996/11/18
N2 - We examined the role of serotonin 1A (5-HT(1A)) receptors in the inhibitory effects of methamphetamine (MA) on photic entrainment to the circadian pacemaker in the suprachiasmatic nucleus (SCN) of rodents. MA inhibited optic nerve stimulation-evoked field potential in the SCN, light-induced Fos expression in the SCN and light-induced phase shift of hamster wheel-running rhythm. NAN-190, a 5-HT(1A) receptor antagonist, eliminated the inhibitory effects of MA. NAN-190 has also been reported to antagonize α1 adrenergic receptors. However, prazosin, which selectively antagonizes α1 adrenergic receptors, did not affect the inhibitory action of MA on light-induced Fos expression. In addition, parachloroamphetamine, which is known to be a 5-HT releaser, dose-dependently inhibited light-induced phase shift of wheel-running rhythm. These findings suggest that elevation of endogenous 5-HT levels by MA inhibits the photic entraining responses of the circadian pacemaker in the SCN via 5-HT(1A) receptor stimulation of the 5-HT released by MA.
AB - We examined the role of serotonin 1A (5-HT(1A)) receptors in the inhibitory effects of methamphetamine (MA) on photic entrainment to the circadian pacemaker in the suprachiasmatic nucleus (SCN) of rodents. MA inhibited optic nerve stimulation-evoked field potential in the SCN, light-induced Fos expression in the SCN and light-induced phase shift of hamster wheel-running rhythm. NAN-190, a 5-HT(1A) receptor antagonist, eliminated the inhibitory effects of MA. NAN-190 has also been reported to antagonize α1 adrenergic receptors. However, prazosin, which selectively antagonizes α1 adrenergic receptors, did not affect the inhibitory action of MA on light-induced Fos expression. In addition, parachloroamphetamine, which is known to be a 5-HT releaser, dose-dependently inhibited light-induced phase shift of wheel-running rhythm. These findings suggest that elevation of endogenous 5-HT levels by MA inhibits the photic entraining responses of the circadian pacemaker in the SCN via 5-HT(1A) receptor stimulation of the 5-HT released by MA.
KW - 5-HT(1A) receptor
KW - NAN-190
KW - circadian rhythm
KW - methamphetamine
KW - serotonin
KW - suprachiasmatic nucleus
UR - http://www.scopus.com/inward/record.url?scp=0030592587&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030592587&partnerID=8YFLogxK
U2 - 10.1016/S0006-8993(96)00860-8
DO - 10.1016/S0006-8993(96)00860-8
M3 - Article
C2 - 8973823
AN - SCOPUS:0030592587
VL - 740
SP - 261
EP - 267
JO - Brain Research
JF - Brain Research
SN - 0006-8993
IS - 1-2
ER -