title: Circadian rhythms of occipital-cortex temperature and motor activity in young and old rats under chronic protein malnutrition.
abstract: The circadian rhythm of cortical temperature registered in the right occipital cortex and the circadian rhythm of motor activity were studied in young and old rats submitted to a chronic malnutrition paradigm. Circadian rhythms of cortical temperature and motor activity in Control (25% casein) and Malnourished (6% casein) Sprague-Dawley male rats were registered by telemetry along different lighting conditions. Results indicate that: (1) there are masking effects of light upon the period of cortical temperature in malnourished-old rats, (2) cortical temperature and motor-activity rhythms, show endogenous periods different from 24-h under free-running conditions, (3) protein malnutrition increases the amplitude and the mean value of cortical-temperature rhythm in malnourished-young rats, (4) aging decreases the amplitude and mean value of the motor-activity rhythm, (5) the acrophase of cortical temperature is delayed in malnourished-old rats, and (6) the temporal relationship between cortical temperature and motor-activity circadian rhythms is altered in malnourished-young and old rats. Therefore, this study provides evidence that protein malnutrition produces long-lasting alterations in the architecture of the circadian system, particularly affecting cortical-temperature oscillation. These changes might indicate thermoregulatory differences in the brain of malnourished rats that could be related to metabolic and behavioral alterations due to protein malnutrition.
authors.affiliation: Lab. EEG y Cronobiología, Instituto de Neurobiología, UNAM-UAQ Juriquilla, Querétaro, México.
authors.forename: O
authors.initials: O
authors.lastname: Castañón-Cervantes
authors.forename: L
authors.initials: L
authors.lastname: Cintra
mesh_terms: D000375:Aging; D000818:Animals; D002940:Circadian Rhythm; D008297:Male; D009043:Motor Activity; D009778:Occipital Lobe / Q000503:physiopathology*; D011488:Protein Deficiency / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley