ISSN:
1432-1351
Keywords:
Calliphora vicina
;
Circadian rhythms
;
Phase response curve
;
RH 5849
;
Ecdysteroids
;
Computer modelling
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract RH 5849, a non-steroidal ecdysteroid mimic, was found to cause consistent phase shifts in the circadian rhythm of locomotor activity of the blowfly, Calliphora vicina. This compound causes phase advances in the early subjective night and phase delays in the late subjective night. This effect is the opposite, but not the mirror image of the phase response curve obtained for 1 h light pulses. This suggests that ecdysteroids might act as entraining agents via the output pathway by feedback to “clock” neurons in the brain. A computer model based on 12 pacemaker neurons with circadian periods (τ values) from short to long without simulated feedback from the ecdysteroid system becomes arrhythmic; with feedback, the oscillators become synchronized to a common period. The possible role of ecdysteroids as endogenous synchronizing agents in the insect circadian system is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00214719
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