Optogenetic Stimulation of Arcuate Nucleus Kiss1 Neurons Reveals a Steroid-Dependent Glutamatergic Input to POMC and AgRP Neurons in Male Mice.
Kisspeptin (Kiss1) neurons are essential for reproduction, but their role in the control of energy balance and other homeostatic functions remains unclear. Proopiomelanocortin (POMC) and agouti-related peptide (AgRP) neurons, located in the arcuate nucleus (ARC) of the hypothalamus, integrate numerous excitatory and inhibitory inputs to ultimately regulate energy homeostasis. Given that POMC and AgRP neurons are contacted by Kiss1 neurons in the ARC (Kiss1(ARC)) and they express androgen receptors, Kiss1(ARC) neurons may mediate the orexigenic action of testosterone via POMC and/or AgRP neurons. Quantitative PCR analysis of pooled Kiss1(ARC) neurons revealed that mRNA levels for Kiss1 and vesicular glutamate transporter 2 were higher in castrated male mice compared with gonad-intact males. Single-cell RT-PCR analysis of yellow fluorescent protein (YFP) ARC neurons harvested from males injected with AAV1-EF1α-DIO-ChR2:YFP revealed that 100% and 88% expressed mRNAs for Kiss1 and vesicular glutamate transporter 2, respectively. Whole-cell, voltage-clamp recordings from nonfluorescent postsynaptic ARC neurons showed that low frequency photo-stimulation (0.5 Hz) of Kiss1-ChR2:YFP neurons elicited a fast glutamatergic inward current in POMC and AgRP neurons. Paired-pulse, photo-stimulation revealed paired-pulse depression, which is indicative of greater glutamate release, in the castrated male mice compared with gonad-intact male mice. Group I and group II metabotropic glutamate receptor agonists depolarized and hyperpolarized POMC and AgRP neurons, respectively, which was mimicked by high frequency photo-stimulation (20 Hz) of Kiss1(ARC) neurons. Therefore, POMC and AgRP neurons receive direct steroid- and frequency-dependent glutamatergic synaptic input from Kiss1(ARC) neurons in male mice, which may be a critical pathway for Kiss1 neurons to help coordinate energy homeostasis and reproduction.
Department of Physiology and Pharmacology (C.CN., J.Q., C.Z., M.A.B., S.A.A., O.K.R., M.J.K.) and Anesthesiology and Perioperative Medicine and Knight Cardiovascular Institute (W.F.), Oregon Health & Science University, Portland, Oregon 97239; Division of Neuroscience (O.K.R., M.J.K.), Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon 97006; and Howard Hughes Medical Institute (S.L.P., R.D.P.), University of Washington, Seattle, Washington 98195.
Casey C
CC
Nestor
Department of Physiology and Pharmacology (C.CN., J.Q., C.Z., M.A.B., S.A.A., O.K.R., M.J.K.) and Anesthesiology and Perioperative Medicine and Knight Cardiovascular Institute (W.F.), Oregon Health & Science University, Portland, Oregon 97239; Division of Neuroscience (O.K.R., M.J.K.), Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon 97006; and Howard Hughes Medical Institute (S.L.P., R.D.P.), University of Washington, Seattle, Washington 98195.
Jian
J
Qiu
Department of Physiology and Pharmacology (C.CN., J.Q., C.Z., M.A.B., S.A.A., O.K.R., M.J.K.) and Anesthesiology and Perioperative Medicine and Knight Cardiovascular Institute (W.F.), Oregon Health & Science University, Portland, Oregon 97239; Division of Neuroscience (O.K.R., M.J.K.), Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon 97006; and Howard Hughes Medical Institute (S.L.P., R.D.P.), University of Washington, Seattle, Washington 98195.
Stephanie L
SL
Padilla
Department of Physiology and Pharmacology (C.CN., J.Q., C.Z., M.A.B., S.A.A., O.K.R., M.J.K.) and Anesthesiology and Perioperative Medicine and Knight Cardiovascular Institute (W.F.), Oregon Health & Science University, Portland, Oregon 97239; Division of Neuroscience (O.K.R., M.J.K.), Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon 97006; and Howard Hughes Medical Institute (S.L.P., R.D.P.), University of Washington, Seattle, Washington 98195.
Chunguang
C
Zhang
Department of Physiology and Pharmacology (C.CN., J.Q., C.Z., M.A.B., S.A.A., O.K.R., M.J.K.) and Anesthesiology and Perioperative Medicine and Knight Cardiovascular Institute (W.F.), Oregon Health & Science University, Portland, Oregon 97239; Division of Neuroscience (O.K.R., M.J.K.), Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon 97006; and Howard Hughes Medical Institute (S.L.P., R.D.P.), University of Washington, Seattle, Washington 98195.
Martha A
MA
Bosch
Department of Physiology and Pharmacology (C.CN., J.Q., C.Z., M.A.B., S.A.A., O.K.R., M.J.K.) and Anesthesiology and Perioperative Medicine and Knight Cardiovascular Institute (W.F.), Oregon Health & Science University, Portland, Oregon 97239; Division of Neuroscience (O.K.R., M.J.K.), Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon 97006; and Howard Hughes Medical Institute (S.L.P., R.D.P.), University of Washington, Seattle, Washington 98195.
Wei
W
Fan
Department of Physiology and Pharmacology (C.CN., J.Q., C.Z., M.A.B., S.A.A., O.K.R., M.J.K.) and Anesthesiology and Perioperative Medicine and Knight Cardiovascular Institute (W.F.), Oregon Health & Science University, Portland, Oregon 97239; Division of Neuroscience (O.K.R., M.J.K.), Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon 97006; and Howard Hughes Medical Institute (S.L.P., R.D.P.), University of Washington, Seattle, Washington 98195.
Sue A
SA
Aicher
Department of Physiology and Pharmacology (C.CN., J.Q., C.Z., M.A.B., S.A.A., O.K.R., M.J.K.) and Anesthesiology and Perioperative Medicine and Knight Cardiovascular Institute (W.F.), Oregon Health & Science University, Portland, Oregon 97239; Division of Neuroscience (O.K.R., M.J.K.), Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon 97006; and Howard Hughes Medical Institute (S.L.P., R.D.P.), University of Washington, Seattle, Washington 98195.
Richard D
RD
Palmiter
Department of Physiology and Pharmacology (C.CN., J.Q., C.Z., M.A.B., S.A.A., O.K.R., M.J.K.) and Anesthesiology and Perioperative Medicine and Knight Cardiovascular Institute (W.F.), Oregon Health & Science University, Portland, Oregon 97239; Division of Neuroscience (O.K.R., M.J.K.), Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon 97006; and Howard Hughes Medical Institute (S.L.P., R.D.P.), University of Washington, Seattle, Washington 98195.
Oline K
OK
Rønnekleiv
Department of Physiology and Pharmacology (C.CN., J.Q., C.Z., M.A.B., S.A.A., O.K.R., M.J.K.) and Anesthesiology and Perioperative Medicine and Knight Cardiovascular Institute (W.F.), Oregon Health & Science University, Portland, Oregon 97239; Division of Neuroscience (O.K.R., M.J.K.), Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon 97006; and Howard Hughes Medical Institute (S.L.P., R.D.P.), University of Washington, Seattle, Washington 98195.
Martin J
MJ
Kelly
D000200:Action Potentials / Q000187:drug effects / Q000528:radiation effects; D054369:Agouti-Related Protein / Q000378:metabolism*; D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D002369:Castration; D000075402:Channelrhodopsins / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism*; D059648:Kisspeptins / Q000378:metabolism*; D008027:Light; D008297:Male; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D062308:Optogenetics; D011333:Pro-Opiomelanocortin / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists / Q000378:metabolism; D013256:Steroids / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects / Q000528:radiation effects; D050599:Vesicular Glutamate Transport Protein 2 / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D054369:Agouti-Related Protein; D000075402:Channelrhodopsins; D005971:Glutamates; D059648:Kisspeptins; D012333:RNA, Messenger; D018094:Receptors, Metabotropic Glutamate; D013256:Steroids; D050599:Vesicular Glutamate Transport Protein 2; C108822:metabotropic glutamate receptor 2; D005680:gamma-Aminobutyric Acid; D011333:Pro-Opiomelanocortin