Fig. 4.
Mean number of Fos-IR neurons within nuclear regions of the pontomesenphalic tegmentum (PMT) in controls and during postcarbachol days 01, 03, 05, and 07 of LTPE. (A) LDT, (B) PPT, (C) PBN, (D) L/MVN. The number of Fos-IR neurons within the vicinity of the drug injection site in the PBN increases only on day 01 (*P < 0.0001) followed by a decrease over the course of the LTPE effect. Conversely, the number of Fos-IR neurons in the LDT, PPT, and L/MVN increases after day 01 reaching a peak on day 03 (*P < 0.0001). This distinctly different distribution and time course of Fos-IR neurons is also seen in Fig. 3. There are significantly more Fos-IR neurons ipsilateral to the microinjection site in the PBN and only on day 01. In all other cell groups, there is no significant difference (P > 0.05) in the number of Fos-IR neurons between ipsilateral and contralateral regions.