Do the suprachiasmatic nuclei oscillate in old rats as they do in young ones?
| Autor: | M. Medanic, Evelyn Satinoff, Angela J. McArthur, Martha U. Gillette, Hua Li, Chen Liu, T. K. Tcheng |
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| Rok vydání: | 1993 |
| Předmět: |
Male
Aging medicine.medical_specialty Physiology Central nervous system Drinking Behavior In Vitro Techniques Motor Activity Biology Body Temperature Rhythm Slice preparation Physiology (medical) Internal medicine Computer Graphics medicine Animals Homeostasis Premovement neuronal activity Circadian rhythm Suprachiasmatic nucleus Brain Circadian Rhythm Rats medicine.anatomical_structure Endocrinology nervous system Light effects on circadian rhythm Hypothalamus Female Suprachiasmatic Nucleus sense organs Neuroscience |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 265:R1216-R1222 |
| ISSN: | 1522-1490 0363-6119 |
| Popis: | The basis of the decline in circadian rhythms with aging was addressed by comparing the patterns of three behavioral rhythms in young and old rats with the in vitro rhythm of neuronal activity in the suprachiasmatic nuclei (SCN), the primary circadian pacemaker. In some old rats, rhythms of body temperature, drinking, and activity retained significant 24-h periodicities in entraining light-dark cycles; in others, one or two of the rhythms became aperiodic. When these rats were 23-27.5 mo old they were killed, and single-unit firing rates in SCN brain slices were recorded continuously for 30 h. There was significant damping of mean peak neuronal firing rates in old rats compared with young. SCN neuronal activities were analyzed with reference to previous entrained behavioral rhythm patterns of individual rats as well. Neuronal activity from rats with prior aperiodic behavioral rhythms was erratic, as expected. Neuronal activity from rats that were still maintaining significant 24-h behavioral rhythmicity at the time they were killed was erratic in most cases but normally rhythmic in others. Thus there was no more congruence between the behavioral rhythms and the brain slice rhythms than there was among the behavioral rhythms alone. These results, the first to demonstrate aberrant SCN firing patterns and a decrease in amplitude in old rats, imply that aging could either disrupt coupling between SCN pacemaker cells or their output, or cause deterioration of the pacemaking properties of SCN cells. |
| Databáze: | OpenAIRE |
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