How and why we sleep are central unsolved questions in medicine. Nearly 40 million people in the United States are estimated to experience chronic or intermittent sleep disorders such as narcolepsy, sleep apnea, restless leg syndrome and insomnia. Traditional approaches have identified several neuronal populations whose interplay is important in generating sleep and wakefulness. How that interplay is established, how it is altered and its cellular and molecular consequences, remain poorly understood. The long-term objective of this proposal is to determine the molecular identity and function of ion channels and receptors expressed by sleep-related neurons in order to understand the molecular mechanisms controlling sleep generation. This application focuses on the identity and function of a family of K+ channels subunit genes in controlling activity of mesopontine cholinergic neurons which are believed to play a pivotal role in the generation of wakefulness and REM sleep. Our central hypothesis is that K+ channels formed by Kv3 subunits regulate action potential shape, intracellular Ca2+ levels, repetitive firing and the release of transmitter from mesopontine cholinergic neurons. To test this hypothesis we will use pharmacological methods with whole-cell patch clamp recordings in brain slices from wild-type and Kv3 knock-out mice. The results of these studies will 1) identify and verify the intrinsic electrophysiological properties of important REM-sleep related neurons in mouse; 2) determine the molecular identity and function of native K+ channels formed by Kv3 subunits; 3) elucidate new mechanisms controlling the activity and release of transmitter by REM sleep-related neurons; 4) identify novel functions of Kv3 channels which have previously been associated with the fast-spiking phenotype rather than broad-spiking phenotype of brainstem cholinergic neurons. These results will contribute to our understanding of the molecular basis of sleep regulation as well as advancing the mouse as a platform for future sleep research.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZHL1-CSR-R (S1))
Program Officer
Twery, Michael
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
New York Medical College
Schools of Medicine
United States
Zip Code
Ishibashi, Masaru; Gumenchuk, Iryna; Miyazaki, Kenichi et al. (2016) Hypocretin/Orexin Peptides Alter Spike Encoding by Serotonergic Dorsal Raphe Neurons through Two Distinct Mechanisms That Increase the Late Afterhyperpolarization. J Neurosci 36:10097-115
Christensen, Mark H; Ishibashi, Masaru; Nielsen, Michael L et al. (2014) Age-related changes in nicotine response of cholinergic and non-cholinergic laterodorsal tegmental neurons: implications for the heightened adolescent susceptibility to nicotine addiction. Neuropharmacology 85:263-83
Leonard, C S; Kukkonen, J P (2014) Orexin/hypocretin receptor signalling: a functional perspective. Br J Pharmacol 171:294-313
Kukkonen, J P; Leonard, C S (2014) Orexin/hypocretin receptor signalling cascades. Br J Pharmacol 171:314-31
Kohlmeier, Kristi A; Tyler, Christopher J; Kalogiannis, Mike et al. (2013) Differential actions of orexin receptors in brainstem cholinergic and monoaminergic neurons revealed by receptor knockouts: implications for orexinergic signaling in arousal and narcolepsy. Front Neurosci 7:246
Kohlmeier, Kristi A; Ishibashi, Masaru; Wess, Jurgen et al. (2012) Knockouts reveal overlapping functions of M(2) and M(4) muscarinic receptors and evidence for a local glutamatergic circuit within the laterodorsal tegmental nucleus. J Neurophysiol 108:2751-66
Kalogiannis, Mike; Hsu, Emily; Willie, Jon T et al. (2011) Cholinergic modulation of narcoleptic attacks in double orexin receptor knockout mice. PLoS One 6:e18697
Kalogiannis, M; Grupke, S L; Potter, P E et al. (2010) Narcoleptic orexin receptor knockout mice express enhanced cholinergic properties in laterodorsal tegmental neurons. Eur J Neurosci 32:130-42
Ishibashi, Masaru; Leonard, Christopher S; Kohlmeier, Kristi A (2009) Nicotinic activation of laterodorsal tegmental neurons: implications for addiction to nicotine. Neuropsychopharmacology 34:2529-47
Kohlmeier, K A; Watanabe, S; Tyler, C J et al. (2008) Dual orexin actions on dorsal raphe and laterodorsal tegmentum neurons: noisy cation current activation and selective enhancement of Ca2+ transients mediated by L-type calcium channels. J Neurophysiol 100:2265-81

Showing the most recent 10 out of 19 publications