Both Prevention of Physical Contact and Removal of Distal Cues Mediate Cortisol and Vocalization Responses of Guinea Pig Pups to Maternal Separation in a Novel Environment

Exposure of guinea pig pups to a test cage for 30 min evoked more vocalizations, and among females, higher levels of plasma cortisol if the pups were tested alone than if the mother was present behind a wire-mesh partition. Exposure with the mother behind the partition evoked more vocalizations at the oldest of three test ages, and among females, higher levels of plasma cortisol than did exposure to the test cage with the mother freely accessible. These results indicate that the deprivation of both contact-derived and distal maternal cues contribute to the vocalization response of separated guinea pig pups, and for female pups, to the plasma cortisol elevations evoked by the separation procedure