An abnormal annual rhythm in adrenaline excretion and grooming reflexes in cats with pontile lesions

Abstract

Cats with pontile lesions exhibit grooming reflexes (e.g., the scratch reflex), and the receptive field for the grooming reflexes (the area on the body surface whose stimulation elicits the grooming reflexes) systematically varies in size, exhibiting long‐term rhythmic changes during a year. Several lines of evidence suggested that the rhythms in adrenaline may be altered in the cats with lesions and underlie the changes in the size of the receptive field. Therefore, the size of the receptive field for grooming reflexes and adrenomedullary function (as measured by the urinary excretion of adrenaline) were monitored for one year in eight normal cats and six cats with pontile lesions. Periodic regression, analysis of variance, and correlational methods revealed a lesion‐induced change in the annual adrenaline rhythm. No changes in amplitude or overall mean value were detected, but the annual peak in adrenaline excretion occurred approximately four months late, in June instead of February. The abnormality in the adrenaline rhythm was inversely and significantly correlated with the size of the receptive field for the grooming reflexes. Chronopathological changes in rhythmic parameters are discussed as important considerations in the behavioral abnormalities which appear following lesions of the central nervous system.

Abstracting Keywords:

• cats
• behavior
• central nervous system
• annual rhythms
• adrenaline

Notes

Department of Psychology, Carroll College, Waukesha, Wisconsin 53186, USA

Department of Psychology, University of Iowa, Iowa City, Iowa 52242, USA