6533b7d9fe1ef96bd126c1db

RESEARCH PRODUCT

Day/night changes of pineal gland volume and pinealocyte nuclear size assessed over 10 consecutive days

H. A. WelkerLutz VollrathU. HeidbüchelB. J. M. Diehl

subject

MalePeriodicitymedicine.medical_specialtyLightKaryometryPeriod (gene)BiologyPineal GlandPinealocytePineal glandRhythmInternal medicineTestismedicineAnimalsNuclear volumeCircadian rhythmBiological PsychiatryCell NucleusBody WeightRats Inbred StrainsOrgan SizeCircadian RhythmRatsPsychiatry and Mental healthmedicine.anatomical_structureEndocrinologyNeurologyVolume (thermodynamics)sense organsNeurology (clinical)

description

Previous studies aimed at elucidating day/night changes of pineal gland size and pinealocyte nuclear volume have yielded contradictory results. The aim of the present investigation was to examine the above parameters over a period of 10 successive days, at 6-hour intervals under a lighting regimen of LD 12:12 (7 a.m. to 7 p.m.). It was found that changes in pineal gland volume could not be correlated with the light/dark phases; instead, a rhythm with a two-day period was encountered. Pinealocyte nuclear volume, by contrast, showed clear circadian changes, exhibiting troughs during photophase and peaks during scotophase. In this experimental series, the karyometric results conformed to the melatonin forming rhythm in the rat pineal gland as reported in the literature.

https://doi.org/10.1007/bf01254762