Age-dependent modulation of circadian parameters in the field mouseMus booduga

✍ Scribed by Sharma, Vijay Kumar; Chandrashekaran, Maroli K.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 227 KB
• Volume: 280
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/(sici)1097-010x(19980401)280:5<321::aid-jez1>3.0.co;2-q

✦ Synopsis

The locomotor activity of the field mouse Mus booduga was monitored under continuous darkness (DD) for extended periods of 275 to 388 days. Free-running period (τ), activity time (α) and rest time (ρ) were computed from the activity records for all the animals (n = 10). Decreases in the circadian period (τ) with age were observed in some of the animals at an early age (<ca. 100 days) and then τ remained relatively constant for rest of their life span. The activity time (α), rest time (ρ), and their ratio (α/ρ), however, did not show any consistent trend of increase/decrease. The initial decrease in τ is consistent with previous models suggesting a timedependent increase in the number of cells generating oscillations in the suprachiasmatic nucleus (SCN) and/or increase in the strength of coupling between these cells. In such models, after an optimal number of cells launch themselves into a state of self-sustained oscillation, τ stabilizes, achieving relative constancy, a pattern similar to the one observed in our study.