Ethanol modulates mammalian circadian clock phase resetting through extrasynaptic gaba receptor activation

doi:10.1016/j.neuroscience.2009.08.020

Neuroscience

Volume 164, Issue 2, 1 December 2009, Pages 842-848

https://doi.org/10.1016/j.neuroscience.2009.08.020 Get rights and content

Abstract

Ethanol modulates the actions of multiple neurotransmitter systems, including GABA. However, its enhancing effects on GABA signaling typically are seen only at high concentrations. In contrast, although GABA is a prominent neurotransmitter in the circadian clock of the suprachiasmatic nucleus (SCN), we see ethanol modulation of clock phase resetting at low concentrations (<50 mM). A possible explanation is that ethanol enhances GABAergic signaling in the SCN through activating GABA_A receptors that contain the δ subunit (GABA_Aδ receptors), which are sensitive to low ethanol concentrations. Therefore, we investigated whether ethanol acts on GABA_Aδ receptors in the SCN. Here we show that acute application of the GABA_Aδ receptor antagonist, RO15-4513, to mouse hypothalamic slices containing the SCN prevents ethanol inhibition of nighttime glutamate-induced (photic-like) phase delays of the circadian clock. Diazepam, which enhances activity of GABA_A receptors containing the γ subunit (GABA_Aγ receptors), does not modulate these phase shifts. Moreover, we find that RO15-4513 prevents ethanol enhancement of daytime serotonergic (non-photic) phase advances of the circadian clock. Furthermore, diazepam phase-advances the SCN circadian clock when applied alone in the daytime, while ethanol has no effect by itself at that time. These data support the hypothesis that ethanol acts on GABA_Aδ receptors in the SCN to modulate photic and non-photic circadian clock phase resetting. They also reveal distinct modulatory roles of different GABA_A receptor subtypes in circadian clock phase regulation.

Section snippets

Brain slice preparation

Coronal brain slices (500 μm) containing the SCN were prepared during the daytime from adult, male C57BL/J6 mice, housed in a 12-h light/dark cycle, as reported previously (Prosser and Gillette 1989, Prosser et al 1993, Prosser 1998). All experimental protocols were approved by the University of Tennessee Knoxville Institutional Animal Care and Use Committee, and experiments were designed to minimize the use and suffering of the animals. Slices were prepared between zeitgeber time (ZT) 0–4

Ethanol inhibition of glutamate-induced phase shifts is dose-dependently blocked by RO15-4513

We have shown previously that 1 mM glutamate applied at ZT 16 phase delays the SCN neuronal activity rhythm by about 3 h, and these phase delays are completely blocked by co-treatment with 20 mM ethanol (ED₅₀ ≈10 mM) (Prosser et al., 2008). Here we show (Fig. 1A) that when we applied the GABA_Aδ receptor antagonist, RO15-4513, together with glutamate and ethanol, it completely reversed the inhibition by ethanol. The reversal effect of RO15-4513 was dose-dependent, with an ED₅₀ of about 75 nM (

Discussion

Ethanol modulation of GABA signaling is a well documented phenomenon. For example, ethanol increases GABA_A chloride currents and GABA-induced membrane hyperpolarization (Hanchar et al 2005, Wallner et al 2003, Carta et al 2004, Nusser and Mody 2002, Sigel et al 1993, Borghese et al 2006). Treatments that increase GABAergic tone enhance ethanol actions, while those that decrease GABAergic activity inhibit ethanol actions (Weiner and Valenzuela 2006, Vengeliene et al 2008). More controversial

Conclusion

Ethanol at low concentrations modulates glutamatergic and serotonergic phase shifts of the SCN circadian clock in vitro at least in part through activating GABA_Aδ receptors. These actions of ethanol within the SCN are distinct from those of the benzodiazepine, diazepam. Diazepam, which enhances GABA_Aγ receptor activity, phase-advances the SCN circadian clock when applied alone during the daytime and does not inhibit nighttime phase delays induced by glutamate. The difference between these two

Acknowledgments

We gratefully acknowledge the advice of Dr. Kimberly Nixon. This research was supported by National Institutes of Health grant AA015948 and the University of Tennessee.

References (57)

M.A. Belenky et al.
Presynaptic and postsynaptic GABA_A receptors in rat suprachiasmatic nucleus
Neuroscience
(2003)
C.M. Borghese et al.
Studies of ethanol actions on recombinant δ-containing γ-aminobutyric acid type A receptors yield contradictory results
Alcohol
(2007)
P. Botta et al.
Modulation of GABA_A receptors in cerebellar granule neurons by ethanol: a review of genetic and electrophysiological studies
Alcohol
(2007)
C.S. Colwell et al.
Photic induction of Fos in the hamster suprachiasmatic nucleus is inhibited by baclofen but not by diazepam or bicucullin
Neurosci Lett
(1993)
B. Gao et al.
GABA_A-receptor subunit composition in the circadian timing system
Brain Res
(1995)
C.F. Gillespie et al.
GABA_A and GABA_B agonists and antagonists alter the phase-shifting effects of light when microinjected into the suprachiasmatic area
Brain Res
(1997)
G.I. Hatton et al.
Brain slice preparation: hypothalamus
Brain Res Bull
(1980)
F. Kawahara et al.
Pharmacological characteristics of GABA_A responses in postnatal suprachiasmatic neurons in culture
Neurosci Lett
(1993)
C. Liu et al.
GABA synchronizes clock cells within the suprachiasmatic circadian clock
Neuron
(2000)
E.M. Mintz et al.
GABA interacts with photic signaling in the suprachiasmatic nucleus to regulate circadian phase shifts
Neuroscience
(2002)

B.F. O'Hara et al.

GABA_A GABA_C, and NMDA receptor subunit expression in the suprachiasmatic nucleus and other brain regions

Mol Brain Res

(1995)

R.W. Olsen et al.

GABA_A receptor subtypes: the “one glass of wine” receptors

Alcohol

(2007)

R.W. Olsen et al.

GABA_A receptors: subtypes provide diversity of function and pharmacology

Neuropharmacology

(2009)

R.A. Prosser

Neuropeptide Y blocks serotonergic phase shifts of the suprachiasmatic circadian clock in vitro

Brain Res

(1998)

R.A. Prosser

Serotonin phase-shifts the mouse suprachiasmatic circadian clock in vitro

Brain Res

(2003)

R.A. Prosser et al.

Serotonergic pre-treatments block in vitro serotonergic phase shifts of the mouse suprachiasmatic nucleus circadian clock

Neuroscience

(2006)

R.A. Prosser et al.

Acute ethanol modulates glutamatergic and serotonergic phase shifts of the mouse circadian clock in vitro

Neuroscience

(2008)

M.R. Ralph et al.

Bicuculline blocks circadian phase delays but not advances

Brain Res

(1985)

M.R. Ralph et al.

Effects of diazepam on circadian phase advances and delays

Brain Res

(1986)

V. Santhakumar et al.

Ethanol acts directly on extrasynaptic subtypes of GABA_A receptors to increase tonic inhibition

Alcohol

(2007)

A. Semyanov et al.

Tonically active GABA_A receptors: modulating gain and maintaining the tone

Trends Neurosci

(2004)

E. Sigel et al.

Recombinant GABA_A receptor function and ethanol

FEBS Lett

(1993)

K. Tominaga et al.

GABA_A receptor agonist muscimol can reset the phase of neural activity rhythm in the rat suprachiasmatic nucleus in vitro

Neurosci Lett

(1994)

J.L. Weiner et al.

Ethanol modulation of GABAergic transmission: the view from the slice

Pharmacol Ther

(2006)

C.M. Borghese et al.

The δ subunit of γ-aminobutyric acid type A receptors does not confer sensitivity to low concentrations of ethanol

J Pharmacol Exp Ther

(2006)

A.J. Brager et al.

Acute ethanol disrupts in vivo photic and nonphotic phase-resetting of the mouse circadian clock

Soc Neurosci

(2009)

M. Carta et al.

Alcohol enhances GABAergic transmission to cerebellar granule cells via an increase in golgi cell excitability

J Neurosci

(2004)

D.-S. Choi et al.

Protein kinase Cδ regulates ethanol intoxication and enhancement of GABA-stimulated tonic current

J Neurosci

(2008)

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Systems NeuroscienceResearch PaperEthanol modulates mammalian circadian clock phase resetting through extrasynaptic gaba receptor activation

Abstract

Section snippets

Brain slice preparation

Ethanol inhibition of glutamate-induced phase shifts is dose-dependently blocked by RO15-4513

Discussion

Conclusion

Acknowledgments

Neuroscience

Alcohol

Alcohol

Neurosci Lett

Brain Res

Brain Res

Brain Res Bull

Neurosci Lett

Neuron

Neuroscience

Mol Brain Res

Alcohol

Neuropharmacology

Brain Res

Brain Res

Neuroscience

Neuroscience

Brain Res

Brain Res

Alcohol

Trends Neurosci

FEBS Lett

Neurosci Lett

Pharmacol Ther

The δ subunit of γ-aminobutyric acid type A receptors does not confer sensitivity to low concentrations of ethanol

J Pharmacol Exp Ther

Acute ethanol disrupts in vivo photic and nonphotic phase-resetting of the mouse circadian clock

Soc Neurosci

Alcohol enhances GABAergic transmission to cerebellar granule cells via an increase in golgi cell excitability

J Neurosci

Protein kinase Cδ regulates ethanol intoxication and enhancement of GABA-stimulated tonic current

J Neurosci

Systems Neuroscience
Research Paper
Ethanol modulates mammalian circadian clock phase resetting through extrasynaptic gaba receptor activation