title: IK1 channels do not contribute to the slow afterhyperpolarization in pyramidal neurons.
abstract: In pyramidal neurons such as hippocampal area CA1 and basolateral amygdala, a slow afterhyperpolarization (sAHP) follows a burst of action potentials, which is a powerful regulator of neuronal excitability. The sAHP amplitude increases with aging and may underlie age related memory decline. The sAHP is due to a Ca(2+)-dependent, voltage-independent K(+) conductance, the molecular identity of which has remained elusive until a recent report suggested the Ca(2+)-activated K(+) channel, IK1 (KCNN4) as the sAHP channel in CA1 pyramidal neurons. The signature pharmacology of IK1, blockade by TRAM-34, was reported for the sAHP and underlying current. We have examined the sAHP and find no evidence that TRAM-34 affects either the current underling the sAHP or excitability of CA1 or basolateral amygdala pyramidal neurons. In addition, CA1 pyramidal neurons from IK1 null mice exhibit a characteristic sAHP current. Our results indicate that IK1 channels do not mediate the sAHP in pyramidal neurons.
authors.affiliation: Vollum Institute, Oregon Health and Science University, Portland, United States.
authors.forename: Kang
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
authors.forename: Pedro
authors.initials: P
authors.lastname: Mateos-Aparicio
authors.affiliation: Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hönigsperger
authors.affiliation: Vollum Institute, Oregon Health and Science University, Portland, United States.
authors.forename: Vijeta
authors.initials: V
authors.lastname: Raghuram
authors.affiliation: Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, United States.
authors.forename: Wendy W
authors.initials: WW
authors.lastname: Wu
authors.affiliation: Queensland Brain Institute, The University of Queensland, Brisbane, Australia.
authors.forename: Margreet C
authors.initials: MC
authors.lastname: Ridder
authors.affiliation: Queensland Brain Institute, The University of Queensland, Brisbane, Australia.
authors.forename: Pankaj
authors.initials: P
authors.lastname: Sah
authors.affiliation: Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, United States.
authors.forename: Jim
authors.initials: J
authors.lastname: Maylie
authors.affiliation: Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
authors.forename: Johan F
authors.initials: JF
authors.lastname: Storm
authors.affiliation: Vollum Institute, Oregon Health and Science University, Portland, United States.
authors.forename: John P
authors.initials: JP
authors.lastname: Adelman
mesh_terms: D000200:Action Potentials; D000818:Animals; D051660:Intermediate-Conductance Calcium-Activated Potassium Channels / Q000235:genetics / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017966:Pyramidal Cells / Q000502:physiology*; D011720:Pyrazoles / Q000378:metabolism; D017208:Rats, Wistar
chemical_list: D051660:Intermediate-Conductance Calcium-Activated Potassium Channels; C496925:Kcnn4 protein, mouse; D011720:Pyrazoles; C411671:TRAM 34
keywords: Afterhyperpolarization; HEK293; IK1; KCNN4; TRAM-34; mouse; neuroscience; rat; sAHP