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. Author manuscript; available in PMC: 2011 Sep 30.
Published in final edited form as: J Neurosci. 2011 Mar 30;31(13):4991–4999. doi: 10.1523/JNEUROSCI.5216-10.2011

Figure 1.

Figure 1

Fear response and fos expression in infant rats with intact mPFC. (A) Percent time freezing (mean ± SEM) during exposure to an adult female rat, cat fur odor, or an adult male rat. Controls were exposed to an empty cage. Male-exposed rats froze significantly more than cat odor, female or control exposed rats (p<.001 for all). Pups exposed to the cat odor froze more than pups exposed to either the control or female (p<.05 for each). (B) Representative micrograph to show FOS staining in the medial amygdala of a male exposed 14 day old pup. (C) FOS expression in the mPFC subdivisions in infant rats with intact mPFC. There were no differences in the number of FOS positive cells (mean ± SEM) in infralimbic and prelimbic mPFC. (D) Activation of the amygdala and PAG in infant rats with intact mPFC. Exposure to the non-threatening stimulus (adult female) or the threatening stimulus (adult male), but not the cat odor, increased the number of FOS positive cells in the medial amygdala and dPAG. Exposure to the adult male and to a lesser extent the cat odor increased FOS in the ventrolateral PAG. MA: medial amygdala, BL/LA: basolateral/lateral amygdala, dPAG: dorsolateral PAG, vPAG: ventrolateral PAG. N=6–9 for all conditions. *** p < 0.001, **P<.01 compared to controls; ^ p<.05 compared to control or female exposed. Note the Y-axis scale differs for Figures 1, 3, and 5 for the prefrontal cortex FOS counts.