Fig. 2.

Effects of shipping on burst firing and stress responses. A: RI plotted for each plane of section for animals shipped at postnatal days 7–8 (P7–8) and P13. Horizontal lines indicate the median. Inset: box and whisker plot of RI from recordings at 34°C grouped by shipping date. **P < 0.005, n = 57 P7–8, n = 26 P13. RI values for interpositus were greater than lateral nucleus in P13-shipped animals (P < 0.01, two-tailed test, corrected for multiple comparisons). Other nucleus-nucleus comparisons, including within P7–8-shipped animals, were not significant. B, left: maternal corticosterone levels in dams of P14 pups shipped 1 day (P13) or 1 wk (P7) previously. Middle: pup body weight. Right: the fraction of TBs under P7–8-shipped, P13-shipped, and after phorbol 12-myristate-13-acetate (PMA) treatment in P13-shipped animals. *P < 0.05, **P < 0.002, ***P < 10⁻⁴.