Zur Beziehung zwischen Phasenlage und Spontanfrequenz bei der endogenen Tagesperiodik

Abstract

The mechanism underlying the endogenous diurnal periodicity of biological processes can be considered a self-sustained oscillation, which can be entrained to an external cycle. In such oscillations the phase-angle of the entrained cycle depends upon the spontaneous frequency (free-running period) of the oscillator.

The activity rhythm of lizards kept in constant light, and in a sinusoidal 24-hour temperature cycle, showed entrainment to this cycle. The phase of the entrained rhythm depended on the spontaneous frequency which was expressed in constant conditions occurring immediately before or after the exposure to the extraneous cycle. This is the first experimental demonstration showing the dependence of phase on the free-running period in an endogenous diurnal rhythm.