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 in pathology 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. Building on our findings from the previous funding period, this application focuses on the identity and function of voltage-gated calcium channels 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 the calcium influx through distinct calcium channels are differentially regulated by cholinergic and monoaminergic inputs and thereby play different roles in altering the integrative properties of mesopontine cholinergic neurons across behavioral state. To test this hypothesis we will use pharmacological methods with whole-cell patch clamp and single- and two-photon calcium imaging and laser uncaging methods in brain slices from wild-type, calcium channel knockout and muscarinic receptor knock-out mice. The results from these studies will 1) determine if Cav2.3 containing calcium channels are inhibited by cholinergic """"""""auto"""""""" receptors in the soma and dendrites of important arousal-related neurons in mouse; 2) determine which of the multiple muscarinc receptors expressed by these neurons inhibit these calcium channels. 3) determine which Ca2+ channels are inhibited by noradrenalin, serotonin and adenosine in the soma and dendrites of these neurons; 4) Determine the role of calcium influx through Cav2.3 channels in regulating dendritic and somatic excitability. These results will contribute to our understanding of the molecular basis of sleep regulation as well as continue to advance the mouse as a platform for future sleep research. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL064150-05A1
Application #
7259915
Study Section
Special Emphasis Panel (ZRG1-IFCN-D (02))
Program Officer
Twery, Michael
Project Start
1999-09-30
Project End
2012-03-31
Budget Start
2007-05-01
Budget End
2008-03-31
Support Year
5
Fiscal Year
2007
Total Cost
$355,500
Indirect Cost
Name
New York Medical College
Department
Physiology
Type
Schools of Medicine
DUNS #
041907486
City
Valhalla
State
NY
Country
United States
Zip Code
10595
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
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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

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