title: Involvement of hippocampal CA3 K(ATP) channels in contextual memory.
abstract: This paper evaluates the involvement of hippocampal ATP-sensitive potassium channels (K(ATP)) in learning and memory. After confirming expression of the Kir6.2 subunit in the CA3 region of C57BL/6J mice, we performed intra-hippocampal pharmacological injections of specific openers and blockers of K(ATP) channels. The opener diazoxide, the blocker tolbutamide, or a mixture of both, were bilaterally injected in the CA3 region before we subjected the animals to a fear conditioning paradigm. Diazoxide strongly impaired contextual memory of mice at both doses tested. This impairment was specifically reversed by co-injecting the blocker tolbutamide. Moreover, we studied the mnemonic abilities of mice deleted for the Kir6.2 subunit. These mice were backcrossed to C57BL/6J mice and tested in two learning paradigms. We found a significant impairment of contextual and tone memories in the Kir6.2 knock-out mice when compared with heterozygous or wild-type animals. Furthermore, these animals were also slightly impaired in a spatial version of the Morris water maze task. Our data suggest a specific involvement of hippocampal K(ATP) Kir6.2/SUR1 channels in memory processes.
authors.affiliation: Université de Toulouse, Centre de Recherches sur la Cognition Animale, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Betourne
authors.forename: Ambre M
authors.initials: AM
authors.lastname: Bertholet
authors.forename: Elodie
authors.initials: E
authors.lastname: Labroue
authors.forename: Hélène
authors.initials: H
authors.lastname: Halley
authors.forename: Hong Shuo
authors.initials: HS
authors.lastname: Sun
authors.forename: Anne
authors.initials: A
authors.lastname: Lorsignol
authors.forename: Zhong-Ping
authors.initials: ZP
authors.lastname: Feng
authors.forename: Robert J
authors.initials: RJ
authors.lastname: French
authors.forename: Luc
authors.initials: L
authors.lastname: Penicaud
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Lassalle
authors.forename: Bernard
authors.initials: B
authors.lastname: Frances
mesh_terms: D000818:Animals; D003981:Diazoxide / Q000494:pharmacology; D005239:Fear; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D054086:KATP Channels / Q000819:agonists* / Q000037:antagonists & inhibitors*; D008124:Locomotion; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D024661:Potassium Channels, Inwardly Rectifying / Q000235:genetics; D014044:Tolbutamide / Q000494:pharmacology; D000099161:Kcnj11 Channel
chemical_list: D003981:Diazoxide; D054086:KATP Channels; D024661:Potassium Channels, Inwardly Rectifying; D014044:Tolbutamide; D000099161:Kcnj11 Channel