Circadian rhythm of serotonin N-acetyltransferase activity in organ culture of chicken pineal gland

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Science  23 Mar 1979:
Vol. 203, Issue 4386, pp. 1245-1247
DOI: 10.1126/science.424750


When chicken pineal glands were organ-cultured in darkness, serotonin N-acetyltransferase activity was low during daytime, increased at midnight, and decreased on the next morning. The autonomous increase of N-acetyltransferase activity was suppressed by illumination of the glands. When pineal glands were cultured under a light-dark cycle (LD 12:12), the change of N-acetyltransferase activity continued to oscillate in phase with the light-dark cycle for 3 days.