Social influences on conditioned cortisol secretion in the squirrel monkey.

Area of Science:

• Neuroendocrinology
• Behavioral Neuroscience
• Primate Social Behavior

Background:

• Social buffering describes how group membership can reduce stress responses.
• The neuroendocrine stress response, particularly involving cortisol, is a key indicator of stress.
• Previous research suggests social housing can mitigate stress in squirrel monkeys.

Purpose of the Study:

• To investigate the effects of social housing conditions on stress-induced cortisol responses in squirrel monkeys.
• To determine if social buffering is dependent on housing conditions during or after stress exposure.

Main Methods:

• An experimental design involving paired (stress + cue) and control (cue only) groups of male squirrel monkeys.
• Exposure to a conditioned stimulus (CS) paired with footshock for the experimental group.
• Testing under individual, dyad, and group housing conditions across four experimental phases.

Main Results:

• Neither group exhibited cortisol responses to the CS before training.
• Following training, only the paired group showed elevated cortisol in response to the CS.
• This stress-induced cortisol elevation in the paired group was observed exclusively under individual housing conditions.

Conclusions:

• Social buffering effects on stress neuroendocrine responses are context-dependent.
• The presence of conspecifics may ameliorate stress responses, but this effect is contingent on housing conditions post-stress.
• These findings highlight the complex interplay between social environment and physiological stress regulation in primates.