TY - JOUR
T1 - Calcium-activated SK potassium channels are key modulators of the pacemaker frequency in locus coeruleus neurons
AU - Matschke, Lina A
AU - Rinné, Susanne
AU - Snutch, Terrance P
AU - Oertel, Wolfgang H
AU - Dolga, Amalia M
AU - Decher, Niels
N1 - Copyright © 2017. Published by Elsevier Inc.
PY - 2018/4
Y1 - 2018/4
N2 - The physiological, intrinsic activity of noradrenergic locus coeruleus (LC) neurons is important for the control of sleep/wakefulness, cognition and autonomous body functions. Dysregulations of the LC-noradrenergic network contribute to the pathogenesis of psychiatric disorders and are key findings in early stages of neurodegenerative diseases. Therefore, identifying ion channels mediating the intrinsic pacemaking mechanism of LC neurons, which is in turn directly coupled to Ca2+homeostasis and cell survival signaling pathways, can help to foster our understanding of the vulnerability of these neurons in neurodegenerative diseases. Small-conductance Ca2+-activated K+(SK) channels regulate the intrinsic firing patterns in different central neurons and are essential regulators of the intracellular Ca2+homeostasis. However, the role of SK channels for the intrinsic pacemaking of LC neurons in mice is still unclear. Therefore we performed qPCR expression analysis as well as patch clamp recordings of in vitro brainstem slices, for instance testing SK channel blockers and activators like apamin and NS309, respectively. Although we found a transcriptional expression of SK1, SK2 and SK3 channels, SK2 was the predominantly expressed subunit in mouse LC neurons. Using perforated-patch clamp experiments, we found that SK channels are essential regulators of the intrinsic pacemaking of LC neurons, mediating a large fraction of the afterhyperpolarization (AHP) in these cells. Consistent with previous observations that a concerted action of L- and T-type Cav channels is essential for the pacemaking of LC neurons, we found that SK channel activation, and the respective AHP amplitude, is primarily coupled to Ca2+influx via these types of Ca2+channels. Our study identified SK2 channels as drug targets for the tuning of the pacemaker frequency in disorders involving a dysregulation of the LC.
AB - The physiological, intrinsic activity of noradrenergic locus coeruleus (LC) neurons is important for the control of sleep/wakefulness, cognition and autonomous body functions. Dysregulations of the LC-noradrenergic network contribute to the pathogenesis of psychiatric disorders and are key findings in early stages of neurodegenerative diseases. Therefore, identifying ion channels mediating the intrinsic pacemaking mechanism of LC neurons, which is in turn directly coupled to Ca2+homeostasis and cell survival signaling pathways, can help to foster our understanding of the vulnerability of these neurons in neurodegenerative diseases. Small-conductance Ca2+-activated K+(SK) channels regulate the intrinsic firing patterns in different central neurons and are essential regulators of the intracellular Ca2+homeostasis. However, the role of SK channels for the intrinsic pacemaking of LC neurons in mice is still unclear. Therefore we performed qPCR expression analysis as well as patch clamp recordings of in vitro brainstem slices, for instance testing SK channel blockers and activators like apamin and NS309, respectively. Although we found a transcriptional expression of SK1, SK2 and SK3 channels, SK2 was the predominantly expressed subunit in mouse LC neurons. Using perforated-patch clamp experiments, we found that SK channels are essential regulators of the intrinsic pacemaking of LC neurons, mediating a large fraction of the afterhyperpolarization (AHP) in these cells. Consistent with previous observations that a concerted action of L- and T-type Cav channels is essential for the pacemaking of LC neurons, we found that SK channel activation, and the respective AHP amplitude, is primarily coupled to Ca2+influx via these types of Ca2+channels. Our study identified SK2 channels as drug targets for the tuning of the pacemaker frequency in disorders involving a dysregulation of the LC.
KW - Journal Article
U2 - 10.1016/j.mcn.2018.03.002
DO - 10.1016/j.mcn.2018.03.002
M3 - Article
C2 - 29524627
VL - 88
SP - 330
EP - 341
JO - Molecular and Cellular Neuroscience
JF - Molecular and Cellular Neuroscience
SN - 1044-7431
ER -