The involvement of calmodulin and Ca2+/calmodulin-dependent protein kinase II in the circadian rhythms controlled by the suprachiasmatic nucleus

Tatsuto Fukushima, Takao Shimazoe, Shigenobu Shibata, Akihito Watanabe, Michiko Ono, Toshiyuki Hamada, Shigenori Watanabe

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    We investigated the involvement of calmodulin and Ca2+/calmodulin- dependent protein kinase II (CaMKII) in the photic entrainment of circadian rhythms using calmodulin inhibitors such as calmidazolium (CMZ) and trifluoperazine (TFP), and a CaMKII inhibitor, KN-62, in rats. Fos expression in the suprachiasmatic nucleus (SCN) of rats induced by photic stimulation (300 lux, 1 h) during the early subjective night of the rats was inhibited by treatment with CMZ (10 mg/kg i.p.) or TFP (20 mg/kg i.p.) 30 min before photic stimulation. With respect to the neuronal firing rate in the rat SCN slice, KN-62 and CMZ application during the early subjective night attenuated the glutamate (10 μM)-induced phase shift. The present results suggest that calmodulin and CaMKII are involved in the photic entrainment mechanism in the rodent SCN.

    Original languageEnglish
    Pages (from-to)45-48
    Number of pages4
    JournalNeuroscience Letters
    Issue number1
    Publication statusPublished - 1997 May 9



    • Ca/calmodulin-dependent protein kinase II
    • Calmodulin
    • Circadian rhythm
    • Photic entrainment
    • Suprachiasmatic nucleus

    ASJC Scopus subject areas

    • Neuroscience(all)

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