Figure 4

Oral application of Methylphenidate (MPH) – Effects on Prefrontal Cortex (PFC). Dopamine (DA) fibre density + S.E.M. is presented in lamina I, III and V of the PFC. Three effects are noteworthy. First, methamphetamine (MA) (= MA-H₂O) impaired the maturation of DA fibres in layer V, as had been shown before [78]. Second, MPH treatment for 30 days returned DA fibre densities to control values in MA-traumatised (= MA-MPH) animals. In control animals, in contrast, MPH (= saline-MPH) did not change the DA fibre densities, or even rather reduced them. Third, application of water (= saline-H₂O), i.e., pure handling, was highly effective in increasing the DA fibre densities in all layers. As isolated rearing by itself allows only for a suppressed maturation of DA fibres, this latter finding suggests that handling is a beneficial, "therapeutic" intervention (Lehmann, Grund et al., unpublished observations). For biostatistics two-way ANOVA with post-hoc contrast analysis among treated groups or pairwise comparisons with t-tests for untreated controls vs. treated groups were used for each lamina; significance values: *p < 0,05, **p < 0,01, ***p < 0,001.