FIGURE 1.

Experimental design. Female and male adult rats were exposed to female and male experimenters in four distinct experiments (Exp1–4). In Experiments 1–2, rats were exposed to opposite-sex experimenters or their T-shirts, whereas rats in the Experiments 3–4 were required to be handled and/or tested by same-sex experimenters. In all experiments animals were manipulated for handling (A), pre-stress open field testing (B), stress (C), stress and post-stress open field testing (D), and blood sampling (E). Rats’ thermal responses to the experimental procedures were recorded by an infrared (IR) thermographic camera in the presence or absence of the experimenters.