Adult hemiparkinsonian rats do not benefit from tactile stimulation

Tactile stimulation (TS) applied to adult rats after cortical injury (medial frontal cortex aspiration or sensorimotor pial stripping stroke model) has been previously shown to ameliorate behavioral impairments and to improve morphological parameters like dendritic length of prefrontal cortical neurons (Gibb et al., 2010). The purpose of this study was to examine the effect of TS on healthy and hemiparkinsonian adult rats. Therefore, the animals received TS for 14 days and 15 min three times daily. At different time points rats were tested in various behavioral tests (amphetamine-induced rotation, cylinder test, staircase test). Finally, rats were sacrificed, their brains removed, and processed for Golgi-Cox analyses, tyrosine hydroxylase immunohistochemistry and quantitative RT-PCR. We found that the striatal 6-OHDA lesion itself induced a long-term increase of astroglial Fgf2 transcript levels, but was not further increased by TS. In contrast TS applied to healthy rats elicited a transient short-term increase of Fgf2 in the striatum and Bdnf, Grin1, and Fgf2 in the hippocampus. Moreover, behavioral and histological analyses do not support a beneficial effect of TS for hemiparkinsonian rats, applied for two weeks starting one day after partial striatal 6-OHDA lesion.