Dual effect of glycine on isolated rat suprachiasmatic neurons

C. Ito, M. Wakamori, N. Akaike

Research output: Contribution to journalArticlepeer-review

49 Citations (Scopus)


Pharmacological properties of strychnine-sensitive and -insensitive glycine receptors have been investigated in rat suprachiasmatic nucleus (SCN) neurons. Because the SCN neurons were too small for stable intracellular recordings by the glass-microelectrode technique was employed on the acutely dissocited SCN neurons. Dissociated SCN neurons were morphologically heterogeneous and could be distinguished into several types. All cells responded to glycine in a concentration-dependent manner. The glycine-induced current was primarily Cl- sensitive and competitively blocked by strychnine. The SCN neurons also responded to excitatory amino acids: glutamate, quisqualate, kainate, and N-methyl-D-aspartate (NMDA). Responses to glutamate and aspartate, which are endogenous neurotransmitter candidates, were ehanced by adding glycine. Glycine especially augmented the maximum response to NMDA in a full concentration range. 6-Cyano-7-nitroquinoxaline-2,3-dione (CNQX) did not suppress the strychnine-sensitive glycine response but did suppress the strychnine-insensitive NMDA response in a competitive manner for glycine. The results suggest that glycine influences neural activity in the SCN as a classical inhibitory neurotransmitter and an excitatory neuromodulator.

Original languageEnglish
Pages (from-to)C213-C218
JournalAmerican Journal of Physiology - Cell Physiology
Issue number2 29-2
Publication statusPublished - 1991


  • Circadian rhythm
  • N-methyl-D-aspartate
  • Rat suprachiasmatic nucleus
  • Whole cell voltage clamp

ASJC Scopus subject areas

  • Physiology
  • Cell Biology


Dive into the research topics of 'Dual effect of glycine on isolated rat suprachiasmatic neurons'. Together they form a unique fingerprint.

Cite this