Premium
Tetrodotoxin resets the clock
Author(s) -
Noguchi Takako,
Watanabe Kazuto
Publication year - 2005
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2005.04180.x
Subject(s) - tetrodotoxin , circadian rhythm , suprachiasmatic nucleus , neuroscience , circadian clock , evening , nmda receptor , hypothalamus , morning , rhythm , vasopressin , light effects on circadian rhythm , biology , medicine , endocrinology , physics , receptor , astronomy
In mammals, circadian rhythms are driven by a pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus. We measured the rhythm of arginine vasopressin release in rat organotypic SCN slices following application of tetrodotoxin (TTX) or N ‐methyl‐ d ‐aspartate (NMDA) at various times throughout the circadian cycle. TTX resets the clock in a manner similar to dark pulses. A 4‐h application of TTX starting in mid subjective day, at around circadian time (CT) 7.0, induced phase advances, while TTX treatment started in early subjective morning, at about CT 2.0, induced phase delays. On the other hand, NMDA resets the clock in a manner similar to a light pulse; that is, NMDA treatment in the early evening induced phase delays while treatment in the late night induced phase advances. The data indicate that deprivation of neuronal firing changes the circadian rhythm.