Formula omitted] effects in thirteen-lined ground squirrels and golden hamsters: Evidence for serotonergic regulation of hibernation

Abstract

1. 1. PCPA ( dl -p- chlorophenylalanine ) inhibition of serotonin synthesis resulted in a marked reduction in occurrence of hypothermia in thirteen-lined ground squirrels ( Citellus tridecemlineatus). 2. 2. The ground squirrels also showed a significant loss in body weight. 3. 3. Golden hamsters ( Mesocricetus auratus) injected with PCPA had significant losses in body weight and fat pad weight, but increases in weights of paired ovaries and paired oviducts. 4. 4. The changes induced by inhibition of serotonin synthesis are generally incompatible with entrance into hibernation. 5. 5. The literature on serotonergic processes provides evidence for endocrine mediation of these seasonal adaptations.