Enhanced hippocampal acetylcholine release in nociceptin-receptor knockout mice.
Nociceptin (NOC), an endogenous ligand of the opioid receptor-like 1 receptor, is thought to be involved in learning and memory processes. Since acetylcholine (ACh) is involved in hippocampal function, and the hippocampus plays a critical role on the learning and memory function, hippocampal ACh release in NOC-receptor knockout mice was examined using an in vivo microdialysis method. The release of hippocampal ACh was largely increased in the knockout mice. Furthermore, in the knockout mice, an enhanced hippocampal theta rhythm, which is known to be linked to hippocampal memory function, was also observed. Immunohistochemically, in septum, co-existence of NOC receptor with cholinergic, but not with GABAergic neurons, was verified. The findings demonstrate that the NOC receptor is involved in hippocampal cholinergic function.
Uezu
Kayoko
K
Department of Integrative Physiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503, Japan.
Sano
Atsuko
A
Sei
Hiroyoshi
H
Toida
Kazunori
K
Houtani
Takeshi
T
Sugimoto
Tetsuo
T
Suzuki-Yamamoto
Toshiko
T
Takeshima
Hiroshi
H
Ishimura
Kazunori
K
Morita
Yusuke
Y
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017551:Microdialysis; D009474:Neurons / Q000378:metabolism; D011957:Receptors, Opioid / Q000235:genetics* / Q000378:metabolism; D013826:Theta Rhythm; D005680:gamma-Aminobutyric Acid / Q000378:metabolism; D000094942:Nociceptin Receptor
D011957:Receptors, Opioid; D005680:gamma-Aminobutyric Acid; D000109:Acetylcholine; D000094942:Nociceptin Receptor; C000722287:Oprl1 protein, mouse