TTX blocks baclofen-induced phase shifts of the mammalian circadian pacemaker in vitro

doi:10.1016/S0006-8993(99)01791-6

Brain Research

Volume 841, Issues 1–2, 11 September 1999, Pages 193-196

https://doi.org/10.1016/S0006-8993(99)01791-6 Get rights and content

Abstract

The mammalian circadian pacemaker, located in the suprachiasmatic nucleus (SCN), expresses 24-h rhythms when isolated in vitro. The GABA_A agonist, muscimol, induces phase advances during the mid-subjective day, while the GABA_B agonist, baclofen, induces both daytime phase advances and nighttime phase delays. Here, we present evidence that tetrodotoxin (TTX) completely blocks baclofen-induced phase shifts in vitro, but does not block in vitro phase advances induced by muscimol. These results suggest that GABA_A, but not GABA_B, receptors are located on SCN pacemaker cells.

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Acknowledgements

This research was supported by NIH grant MH53317 to R.A.P.

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Short communicationTTX blocks baclofen-induced phase shifts of the mammalian circadian pacemaker in vitro

Abstract

Section snippets

Acknowledgements

Brain Res.

TINS

Neurochem. Int.

Brain Res.

Brain Res.

Neurosci. Lett.

Neurosci. Lett.

Neurosci. Lett.

Ultrastructural evidence for intra- and extranuclear projections of GABAergic neurons of the suprachiasmatic nucleus

J. Comp. Neurol.

Short communication
TTX blocks baclofen-induced phase shifts of the mammalian circadian pacemaker in vitro