TY - JOUR
T1 - Investigation of mechanisms mediating 8-OH-DPAT-induced impairment of spatial memory
T2 - Involvement of 5-HT1A receptors in the dorsal hippocampus in rats
AU - Egashira, Nobuaki
AU - Yano, Akiko
AU - Ishigami, Noriko
AU - Mishima, Kenichi
AU - Iwasaki, Katsunori
AU - Fujioka, Masayuki
AU - Matsushita, Michihiko
AU - Nishimura, Ryoji
AU - Fujiwara, Michihiro
N1 - Funding Information:
This study was in part supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan (No. 16591174).
PY - 2006/1/19
Y1 - 2006/1/19
N2 - The purpose of this study was to identify mechanisms that mediate the impairment of spatial memory induced by 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a 5-HT1A/5-HT7 receptor agonist, in the eight-arm radial maze in rats. WAY-100635 and NAN-190, 5-HT1A receptor antagonists, reversed the impairment of spatial memory induced by systemic injection of 8-OH-DPAT (1 mg/kg, i.p.). On the other hand, the α1-adrenoceptor antagonist prazosin and a selective 5-HT 7 receptor antagonist SB269970 had no effect on 8-OH-DPAT-induced impairment of spatial memory. Bilateral microinjection of 8-OH-DPAT (4 μg/side) impaired spatial memory when injected into the dorsal hippocampus (DH). Contrastingly, spatial memory was unaffected by microinjections of 8-OH-DPAT into the other six areas examined: ventral hippocampus (VH), central amygdaloid nucleus (ACE), lateral hypothalamus (LH), nucleus accumbens (NAc), and dorsal (DR) and median (MR) raphe nucleus. Furthermore, NAN-190 significantly reversed the impairment of spatial memory induced by intra-DH injection of 8-OH-DPAT. These findings suggest that 5-HT1A receptors in the DH play an important role in the mechanisms underlying the 8-OH-DPAT-induced impairment of spatial memory in rats.
AB - The purpose of this study was to identify mechanisms that mediate the impairment of spatial memory induced by 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a 5-HT1A/5-HT7 receptor agonist, in the eight-arm radial maze in rats. WAY-100635 and NAN-190, 5-HT1A receptor antagonists, reversed the impairment of spatial memory induced by systemic injection of 8-OH-DPAT (1 mg/kg, i.p.). On the other hand, the α1-adrenoceptor antagonist prazosin and a selective 5-HT 7 receptor antagonist SB269970 had no effect on 8-OH-DPAT-induced impairment of spatial memory. Bilateral microinjection of 8-OH-DPAT (4 μg/side) impaired spatial memory when injected into the dorsal hippocampus (DH). Contrastingly, spatial memory was unaffected by microinjections of 8-OH-DPAT into the other six areas examined: ventral hippocampus (VH), central amygdaloid nucleus (ACE), lateral hypothalamus (LH), nucleus accumbens (NAc), and dorsal (DR) and median (MR) raphe nucleus. Furthermore, NAN-190 significantly reversed the impairment of spatial memory induced by intra-DH injection of 8-OH-DPAT. These findings suggest that 5-HT1A receptors in the DH play an important role in the mechanisms underlying the 8-OH-DPAT-induced impairment of spatial memory in rats.
UR - http://www.scopus.com/inward/record.url?scp=31344437862&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=31344437862&partnerID=8YFLogxK
U2 - 10.1016/j.brainres.2005.10.103
DO - 10.1016/j.brainres.2005.10.103
M3 - Article
C2 - 16386718
AN - SCOPUS:31344437862
SN - 0006-8993
VL - 1069
SP - 54
EP - 62
JO - Brain Research
JF - Brain Research
IS - 1
ER -