Figure 4.

Within CVLM, repeated METH administration reduces TH immunopositive cells without affecting GAD immunopositive cells. Immunohistochemical analysis for TH was performed in dissected brains of mice subjected to repeated injections of saline or METH (5 mg/kg, i.p., for 5 days) and then sacrificed 60 min after the challenge, carried out on day 11. Representative images or TH-positive neurons in A1/C1 within the CVLM of mice treated with saline or METH are shown in (A). The graph in (B) shows the TH-positive cell density (n/mm²) counted in saline- and METH-treated mice. Values are the means ± S.E.M. * p < 0.05 (unpaired two-tailed Student’s t-test). The correlation analysis between values of TH-positive cell density in A1/C1 of the CVLM and the respective SBP values monitored 30 min after the fifth repeated saline/METH injection or following the challenge carried out on day 11 is shown in (C,D), respectively. * p < 0.05, Pearson correlation test. (E) Representative images of double immunostaining for TH and GAD in the CVLM of mice following repeated injections of saline or METH (5 mg/kg, i.p., for 5 days). These mice were sacrificed 60 min following the METH/saline challenge, carried out on day 11. The densitometry (OD: Optical Density) of GAD65/67 immunoreactivity (ir) is shown in (F). Values are the means ± S.E.M. * p < 0.05 (two-tailed Mann-Whitney test).