Norepinephrine and REM sleep
Pierre-Hervé Luppi , Christelle Peyron, Claire Rampon, Damien Gervasoni, Bruno Barbagli, Romuald Boissard and Patrice Fort
Rapid Eye Movement Sleep pp. 107-122B.N. Mallick, S. Inoue (Editors) Narosa Publishing House 1999
TABLE OF CONTENTS

Table of contents

1. Introduction

2. Effect of the application of gaba and glycine antagonists on the activity of the rat locus coeruleus neurons during sleep

3. Glycinergic and gaba-ergic afferent projections to the locus coeruleus

4. Physiological role of the glycinergic inputs to the LC

5. Physiological role of the gaba-ergic inputs to the LC

6. Conclusions and new hypothesis

5. Physiological role of the GABA-ergic inputs to the LC

Our electrophysiological data indicates the existence of a tonic GABA-ergic input on the LC cells during W, SWS and PS. Further, we found that when the same neuron was recorded during short successive periods of SWS and W during the bicuculline effect, its increases in discharge rate was not statistically different between W and SWS. These results highly suggest that GABA release is responsible for the inactivation of LC noradrenergic neurons during SWS. Unfortunately, due to the smaller number of LC cells recorded during PS, we were not able to make the same comparison between SWS and PS. However, with the microdialysis technique, Nitz and Siegel (1997) recently found an increase of the GABA release in the cat LC during SWS and moreover PS as compared to waking values. Based on these and our results, we therefore suggest that during W, the LC cells are under a tonic GABA-ergic inhibition which increases during SWS and even more during PS and is at least partly responsible for the inactivation of these neurons during these states.

Our results indicate that the LC receives GABA-ergic inputs from neurons located in a large number of distant regions from the forebrain to the medulla (Fig. 6). We also observed a substantial number of GAD+/CTb+ neurons in the pontine and mesencephalic periaqueductal gray. These results indicate that the GABA innervation of this nucleus arises from multiple distant GABA-ergic groups in addition to local GABAergic groups. Such result contrast with the classical concept that GABA is mainly contained in interneurons. They suggest that the NA neurons of the LC could be inhibited by multiple populations of GABA-ergic neurons located in different structures and raises the question of the functional role of such complexity. One possibility is that only some of these GABA-ergic afferents are destined to the noradrenergic neurons of the LC. This seems unlikely because the LC in rats contains nearly exclusively noradrenergic cells. Another possibility is that some of these afferents are postsynaptic and others presynaptic, but the more likely explanation is that each of these afferents is active only under specific physiological conditions.

Based on physiological and electrophysiological data (see above), we expect that one or several of these GABA-ergic afferents are "turned on" specifically during SWS and others during PS and are responsible for the progressive decrease of activity of noradrenergic neurons during these sleep states.

The most likely candidate for the inhibition of the noradrenergic neurons during SWS is the lateral preoptic area. Indeed, lesion of this structure in cats and rats induces an insomnia while its stimulation induced SWS (Asala et al., 1990; Lucas and Sterman, 1975; McGinty and Sterman, 1968; Sallanon et al., 1989; John et al., 1994; Sterman and Clemente, 1962). Neurons increasing their activity during SWS have been recorded in this area (Kaitin, 1984; Szymusiak and McGinty, 1986, Koyama and Hayaishi, 1994). Moreover, C-Fos positive cells were observed in the lateral preoptic area after long periods of SWS (Sherin et al., 1996) and it has been further shown that these neurons are in part GABA and galanin positive and project to the tuberomamillary nucleus which contains waking active neurons presumably histaminergic (Vanni-Mercier et al., 1984). From these and our results, we can therefore propose that GABA-ergic neurons in the lateral preoptic area increase their firing just before the onset and during SWS and induce SWS via their inhibitory projections to waking-inducing structures (tuberomamillary nucleus, DRN and LC among others).

Besides the lateral preoptic area, the posterior hypothalamic areas, the periaqueductal gray and the dorsal paragigantocellular nucleus provide substantial GABA inputs to the LC.

The strong GABA-ergic projection from the lateral hypothalamic area is rather puzzling. Indeed, since the initial demonstration that the lesion of the posterior hypothalamus induces somnolence (Von Economo, 1926), the histaminergic neurons of the posterior hypothalamus have been more specifically implicated in waking (Lin et al., 1996). These neurons are located in the tuberomamillary nucleus ventral and caudal to the GABA-ergic neurons from the lateral hypothalamic area projecting to the LC. Nevertheless, muscimol injections in cats in the lateral hypothalamic area in addition to those in the tuberomamillary nucleus induced hypersomnia (Lin et al., 1989). Additional experiments are therefore needed to determine whether the lateral hypothalamic area and its GABA-ergic neurons play a role in vigilance via their projections to the LC.

The GABAergic afferents responsible for the inhibition of noradrenergic neurons during PS should be located in the brainstem. Indeed, it is well known that PS-like episodes occur in pontine or decerebrate cats (Jouvet, 1972). Moreover, it has recently been shown that, in decerebrate animals, PS episodes induced by carbachol injections in the pons are still associated with a cessation of activity of serotonergic neurons of the raphe obscurus and pallidus nuclei (Woch et al., 1996).

In the brainstem, we observed GABA-ergic projections to the LC from the periaqueductal gray and the dorsal paragigantocellular nucleus. In agreement with this last result, local application of bicuculline blocked the dorsal paragigantocellular-evoked inhibition of LC neurons (Ennis and Aston-Jones, 1989). The GABAergic afferents from the periaqueductal gray and the dorsal paragigantocellular nucleus could therefore be responsible for the inhibition of noradrenergic neurons of the LC during PS.

The hypothesis that this inhibition is arising from neurons located in the periaqueductal gray is further supported by two recent studies. Indeed, Yamuy et al showed that after a long period of PS induced by pontine injection of carbachol, a large number of C-Fos positive cells are visible in the DRN and lateral to it (Yamuy et al., 1995). Moreover, Maloney and Jones (1997) observed after a PS rebound induced by deprivation an increase in c-Fos+/GAD+ neurons in the periaqueductal gray and the lateral tegmental nucleus.

Finally, it must be precised that although a number of arguments are in favor of a role of GABA in the inhibition of noradrenergic neurons of the LC during SWS and PS, other inhibitory neuroactive substances might also participate in this inhibition. Indeed, it has for example been shown that LC cells are inhibited by local application of enkephalin (Bird and Kuhar, 1977, Guyenet and Aghajanian, 1979). Moreover, it has been shown that adenosine release increases during wakefulness and decreases during SWS (Porkka-Heiskanen et al., 1997) and adenosine application is inhibitory on LC noradrenergic cells (Pan et al., 1995; Shefner and Chiu, 1986).

The removal during SWS or PS of some tonic excitatory inputs may be present during W (like acetylcholine or glutamate) might also participate in the decrease of activity of LC neurons during sleep.

Next page

REFERENCES
  1. Aghajanian, G.K. and VanderMaelen, C.P., Intracellular identification of central noradrenergic and serotonergic neurons by a new double labeling procedure, J. Neurosci., 2, 1786, 1982.
  2. Akaoka, H., Charléty, P.J., Saunier, C.F., Buda, M. and Chouvet, G., Combining in vivo volume-controlled pressure microinjection with extracellular unit recording, J. Neurosci. Meth., 42, 119, 1992.
  3. Asala, S.A., Okano, Y., Honda, K., Inoue, S., Effects of medial preoptic area lesions on sleep and wakefulness in unrestrained rats, Neurosci. Lett., 114, 300, 1990.
  4. Aston-Jones, G., Ennis, M., Pieribone, V.A., Nickell, W.T. and Shipley, M.T., The brain nucleus locus coeruleus : restricted afferent control of a broad efferent network, Science, 234, 734, 1986.
  5. Aston-Jones, G. and Bloom, F.E., Activity of norepinephrine-containing locus coeruleus neurons in behaving rats anticipates fluctuations in the sleep-waking cycle, J. Neurosci., 1, 876, 1981.
  6. Beitz, A., The Rat Nervous System, Second Edition, G. Paxinos (Ed), San Diego, 173, 1995.
  7. Bird, S.J. and Kuhar, M.J., Iontophoretic applications of opiates to the locus coeruleus, Brain Res., 122, 523, 1977.
  8. Cedarbaum, J.M. and Aghajanian, G.K., Afferent projections to the rat locus coeruleus as determined by a retrograde tracing technique, J.Comp.Neurol., 178, 1, 1978.
  9. Chase, M.H., Soja, P.J. and Morales, F.R., Evidence that glycine mediates the postsynaptic potentials that inhibit lumbar motoneurons during the atonia of active sleep, J. Neurosci., 9, 743, 1989.
  10. Cherubini, E., North, R. A. and Williams., J.T., Synaptic potentials in rat locus coeruleus neurons, J. Physiol. (London), 406, 431, 1988.
  11. Chouvet, G., Akaoka, H. and Aston-Jones, G., Serotonin selectively decreases glutamate-induced excitation of locus coeruleus neurons, C.R. Acad. Sci. (Paris), 306, 339, 1988.
  12. Dahlström, A. and Fuxe, K., Evidence for the existence of monoamine-containing neurons in the central nervous system. I. Demonstration in the cell bodies of brain stem neurons, Acta Physiol. Scand. (Suppl.), 232, 1, 1964.
  13. Darracq, L., Gervasoni, D., Soulière, F., Lin, J.S., Fort, P., Chouvet, G. and Luppi, P-H., Effect of strychnine on rat locus coeruleus neurons during sleep and wakefulness, NeuroReport , 8, 351, 1996.
  14. Ennis, M. and Aston-Jones, G., GABA-mediated inhibition of locus coeruleus from the dorsomedial rostral medulla, J. Neurosci., 9, 2973, 1989.
  15. Gaillard, J.-M., Principles and Practice of Sleep Medicine, M.H. Kryger, T. Roth and W.C. Dement (Eds), Philadelphia, 349, 1994.
  16. Gallager, D.W. and Aghajanian, G.K., Effect of antipsychotic drugs on the firing of dorsal raphe cells. II. Reversal by picrotoxin, Eur. J. Pharmacol., 39, 357, 1976.
  17. Gallager, D.W., Benzodiazepines : potentiation of a GABA inhibitory response in the dorsal raphe nucleus, Eur. J. Pharmacol., 49, 133, 1978.
  18. Gervasoni, D., Darracq, L., Fort P., Soulière F., Chouvet, G and Luppi, P.-H., Electrophysiological evidence that noradrenergic neurones of the rat locus coeruleus are tonically inhibited by GABA during sleep. Eur. J. Neurosci., 10, ,1998.
  19. Guyenet, P.G. and Aghajanian, G.K., Ach, Substance P and Met-Enkephalin in the locus coeruleus : pharmacological evidence for independent sites of action, Eur. J. Pharmacol., 53, 319, 1979.
  20. Henley K. and Morrison A.R., A re-evaluation of the effects of lesions of the pontine tegmentum and locus coeruleus on phenomena of paradoxical sleep in the cat. Acta Neurobiol. Exp (Warszawa), 34, 215, 1974.
  21. Hobson, J., McCarley, R. and Wyzinski, P., Sleep cycle oscillation : reciprocal discharge by two brainstem groups, Science, 189, 55, 1975.
  22. Holstege, J.C. and Bongers, C.M.H., A glycinergic projection from the ventromedial lower brainstem to spinal motoneurons. An ultrastructural double labeling study in rat, Brain Res., 566, 308, 1991.
  23. John, J., Kumar, V.M., Gopinath, G., Ramesh, V., Mallick, H., Changes in sleep-wakefulness after kainic acid lesion of the preoptic area in rats, Jpn. J. Physiol., 44, 231, 1994.
  24. Jones, B.E., Harper S.T., and Halaris A.E., Effects of locus coeruleus lesions upon cerebral monoamines content, sleep-wakefulness states and the response to amphetamine in the cat. Brain Res. 124, 473, 1977.
  25. Jones, B.E., Noradrenergic locus coeruleus neurons : their distant connections and their relationship to neighboring, including cholinergic and GABA-ergic neurons of the central gray and reticular formation, Prog. Brain Res., 88, 15, 1991.
  26. Jouvet, M., The role of monoamines and acetylcholine-containing neurons in the regulation of the sleep, Ergebn. Physiol., 64, 166, 1972.
  27. Jouvet, M. and Delorme F. Locus coeruleus et sommeil paradoxal. C.R. Soc. Biol. (Paris), 159, 895, 1965.
  28. Kaitin, K.I., Preoptic area unit activity during sleep and wakefulness in the cat, Exp. Neurol., 83, 347, 1984.
  29. Kaur, S., Saxena, R.N. and Mallick, B.N., GABA in locus coeruleus regulates spontaneous rapid eye movement sleep by acting on GABAA receptors in freely moving rats, Neurosci. Lett., 223, 105, 1997.
  30. King C.D. and Jewet R.E., The effects of a-methyl-tyrosine on sleep and brain norepinephrine in cats. J. Pharmacol. Exp. Ther., 177, 188, 1971.
  31. Koyama, Y. and Kayama, Y., Mutual interactions among cholinergic, noradrenergic and serotonergic neurons studied by iontophoresis of these transmitters in rat brainstem nuclei, Neuroscience, 55, 117, 1993.
  32. Koyama, Y. and Hayaishi, O., Firing of neurons in the preoptic/anterior hypothalamic areas in rat : its possible involvement in slow wave sleep and paradoxical sleep, Neurosci. Res., 19, 31, 1994.
  33. Lidbrink P., The effect of lesions of ascending noradrenaline pathways on sleep and waking in the rat. Brain Res.;74, 19, 1974
  34. Lin, J-S, Hou, Y., Sakai, K. and Jouvet, M., Histaminergic inputs to the mesopontine tegmentum and their role in the control of cortical activation and wakefulness in the cat, J. Neurosci., 15, 1523, 1996.
  35. Lin, J.S., Sakai, K., Vanni-Mercier, G. and Jouvet, M., A critical role of the posterior hypothalamus in the mechanisms of wakefulness determined by microinjections of muscimol in freely moving cats, Brain Res., 429, 225, 1989.
  36. Lucas, E.A. and Sterman, M.B., Effect of a forebrain lesion on the polycyclic sleep wake patterns in the cat, Exp. Neurol., 46, 368, 1975.
  37. Luppi, P-H, Charléty, P.J., Fort, P., Akaoka, H., Chouvet, G. and Jouvet, M., Anatomical and electrophysiological evidence for a glycinergic inhibitory innervation of the rat locus coeruleus, Neurosci. Lett., 128, 33, 1991.
  38. Luppi, P.H., Aston-Jones, G., Akaoka, H., Chouvet, G. and Jouvet, M. Afferent projections to the rat locus coeruleus demonstrated by retrograde and anterograde tracing with cholera-toxin B subunit and Phaseolus vulgaris leucoagglutinin, Neuroscience, 65, 119, 1995.
  39. Luppi, P-H., Fort, P., and Jouvet, M., Iontophoretic application of unconjugated cholera toxin B subunit CTb combined with immunohistochemistry of neurochemical substances : a method for transmitter identification of retrogradely labeled neurons, Brain Res., 534, 209, 1990.
  40. Luque, J.M., Malherbe, P. and Richards, J.G., Localization of GABAA receptor subunit mRNAs in the rat locus coeruleus, Mol. Brain Res., 24, 219, 1994.
  41. Maloney K.J. and Jones B.E., C-Fos expression in cholinergic, GABAergic and monoaminergic cell groups during paradoxical sleep deprivation and recovery, Abstr. Soc. Neurosci., 23, 2131, 1997.
  42. Maloney, K.J., Cape, E.G., Gotman, J. and Jones, B.E., High-frequency g- encephalogram activity in association with sleep-wake states and spontaneous behaviors in the rat, Neuroscience, 76, 541, 1997.
  43. McCarley R. and Hobson J.A., Single neuron activity in cat gigantocellular tegmental field: Selectivity of discharge in desynchronized sleep. Science, 174, 1250, 1971.
  44. McGinty, D.J and Stermann, M.B., Sleep suppression after basal forebrain lesions in the cat, Science, 160, 1253, 1968.
  45. McGinty, D.J. and Harper, R.M., Dorsal raphe neurons : depression of firing during sleep in cats, Brain Res., 101, 569, 1976.
  46. Masuko, S., Nakajima, Y., Nakajima, S. and Yamaguchi, K., Noradrenergic neurons from the locus coeruleus in dissociated cell culture : culture methods, morphology, and electrophysiology, J. Neurosci., 6, 3229, 1986.
  47. Mendelson, W.B., Neuropharmacology of sleep induction by benzodiazepines, Crit. Rev. Neurobiol., 622, 1, 1992
  48. Nitz, D.A. and Siegel, J.M., GABA release in the locus coeruleus as a function of sleep/wake state, Neuroscience, 78, 795, 1997.
  49. Osmanovic, S.S. and Shefner, S.A., g-aminobutyric acid responses in rat locus coeruleus neurons in vitro : a current-clamp and voltage-clamp study, J. Physiol. (London), 421, 151, 1990.
  50. Pan, W.J., Osmanovic, S.S. and Shefner, S.A., Characterization of the adenosine A1 receptor-activated potassium current in rat locus coeruleus neurons, J. Pharmacol. Exp. Ther., 273, 537, 1995.
  51. Pan, Z.Z. and Williams, J.T., GABA- and glutamate-mediated synaptic potentials in rat dorsal raphe neurons in vitro, J. Neurophysiol., 61, 719, 1989.
  52. Peyron, C., Luppi, P.-H., Fort, P., Rampon, C. and Jouvet, M., Lower brainstem catecholamine afferents to the rat dorsal raphe nucleus, J. Comp. Neurol., 364, 402, 1996.
  53. Peyron, C., Luppi, P-H., Rampon, C. and Jouvet, M., Location of the GABA-ergic neurons projecting to the dorsal raphe nucleus and the locus coeruleus of the rat, Soc. Neurosci. Abstr., 21, 373, 1995.
  54. Porkka-Heiskanen, T., Strecker, R.E., Thakkar, M., Bjorkum, A.A., Greene, R.W. and McCarley, R.W., Adenosine : a mediator of the sleep-inducing effects of prolonged wakefulness, Science, 276, 1265, 1997.
  55. Rampon, C., Peyron, C., Petit, J.M., Fort, P., Gervasoni, D.and Luppi, P.H., Origin of the glycinergic innervation of the rat trigeminal motor nucleus, NeuroReport, 7, 3081, 1996.
  56. Rampon, C., Peyron, C., Gervasoni, D., Cespuglio, R., Fort, P. and Luppi, P-H., Localization of the glycinergic neurons projecting to the rat locus coeruleus, dorsal raphe and trigeminal motor nuclei, Soc. Neurosci. Abstr., 22, 1838,1996.
  57. Sakai, K., Sleep : Neurotransmitters and Neuromodulators, A. Wauquier, J.M. Monti, J.M. Gaillard and M. Radulovacki (eds), New York, 29, 1985.
  58. Sastre, J.P., Buda, C., Kitahama, K. and Jouvet, M., Importance of the ventrolateral region of the periaqueductal gray and adjacent tegmentum in the control of paradoxical sleep as studied by muscimol microinjection in the cat, Neuroscience, 74, 415, 1996.
  59. Sallanon, M., Denoyer, M., Kitahama, K., Aubert, C., Gay, N. and Jouvet, M., Long lasting insomnia induced by preoptic neuron lesions and its transient reversal by muscimol injection into the posterior hypothalamus in the cat, Neuroscience, 32, 669, 1989.
  60. Shefner, S.A. and Chiu, T.H., Adenosine inhibits locus coeruleus neurons : an intracellular study in a rat brain slice preparation, Brain Res., 366, 364, 1986.
  61. Sherin, J.E., Shiromani, P.J., McCarley, R.W., Saper, C.B., Activation of ventrolateral preoptic neurons during sleep, Science, 271, 216, 1996.
  62. Shimizu N., Morikawa N. and Hokada M. Histochemical studies of monoamine oxidase of the brain of rodents. Zeitschrift für Zellforschung, 49, 389, 1959.
  63. Sterman, M.B. and Clemente, C.D., Forebrain inhibitory mechanisms, sleep pattern induced by basal forebrain stimulation in behaving cat, Exp. Neurol., 6, 103, 1962.
  64. Szymusiak, R. and McGinty, D.J., Sleep-related discharge in the basal forebrain of cats, Brain Res., 370, 82, 1986.
  65. Tononi G., Pompeiano M. and Pompeiano O., Modulation of desynchronized sleep through microinjection of beta-adrenergic agonists and antagonists in the dorsal pontine tegmentum of the cat. Pflugers Arch, 415, 142, 1989.
  66. Vanni-Mercier, G., Sakai, K., Salvert, D. and Jouvet, M., Waking-state specific neurons in the caudal hypothalamus of the cat, C.R. Acad. Sci. (Paris), 298, 195, 1984.
  67. Von Economo, C., Handbuch des Normalen und Patholigischen Physiologie, A. Von Bethe G.V., Bergman G., Embden and U.A. Ellinger (Eds), Berlin, 291, 1926.
  68. Wang, Q.P., Ochiai, H. and Nakai, Y., GABA-ergic innervation of serotonergic neurons in the dorsal raphe nucleus of the rat studied by electron microscopy double immunostaining, Brain Res. Bull., 6, 943, 1992.
  69. Williams, J.T., Bobker, D.H. and Harris, G.C., Synaptic potentials in locus coeruleus neurons in brain slices, Prog. Brain Res., 88, 167, 1991.
  70. Williams, J.T., North, R.A., Shefner, A., Nishi, S. and Egan, T.M., Membrane properties of rat locus coeruleus neurons, Neuroscience, 13, 137, 1984.
  71. Woch, G., Davies, R.O., Pack, A.I. and Kubin, L., Behavior of raphe cells projecting to the dorsomedial medulla during carbachol-induced atonia in the cat, J. Physiol. (London), 490, 745, 1996.
  72. Yamuy, J. Mancillas, J.R., Morales, F.R. and Chase, M.H., C-Fos expression in the pons and medulla of the cat during carbachol-induced active sleep, J. Neurosci., 13, 2703, 1993.
  73. Yamuy, J., Sampagna, S., Lopez-Rodriguez, F., Luppi, P-H., Morales, F.R. and Chase, M.H., Fos and serotonin immunoreactivity in the raphe nuclei of the cat during carbachol-induced active sleep : a double-labeling study, Neuroscience, 67, 211, 1995.