Figure 7.

Chemical ablation of the olfactory epithelium of naive partners prevents the transmission of metaplastic LTD from stressed subjects to naive partners. A, Schematic showing the experimental design and timeline. In the experiment, the partner mouse received dichlobenil (150 mg/kg) by intraperitoneal injection on day 1 and the olfactory preference test was used to assess of olfaction on day 9. On day 14, the subject mouse was removed, exposed to a restraint–tailshock stress paradigm for 90 min, and then returned to its home cage and allowed to freely interact with the dichlobenil-treated partner for 30 min before slice preparation. B, Bar graph comparing the total exploratory time spent with the peanut butter subtracted from the time spent with distilled water in the olfactory preference test between control and dichlobenil-treated mice performed at day 9 after lesion. Numbers in parenthesis represent animals examined. C, Representative images of OMP immunostaining in the glomerular layer (GL) of the olfactory bulb of control and lesioned mice. Data were replicated in five mice of each group. D, Summary of experiments showing the induction of hippocampal CA1 LTD by LFS at Schaffer collateral–CA1 synapses in slices from stressed mice. E, Summary of experiments showing the induction of hippocampal CA1 LTD by LFS at Schaffer collateral–CA1 synapses in slices from naive partners. F, Bar graph comparing serum corticosterone levels in stressed mice and naive partners. G, Bar graph illustrating the proportion of individuals that express LTD or no LTD in stressed and naive partner groups. Representative traces of fEPSPs were taken at the time indicated by number. Dashed lines show the level of baseline. Data represent the mean ± SEM. **p < 0.01, ***p < 0.001 compared with control or LTD-expressing stress mice by two-tailed unpaired Student's t test.