Effects of a hard or soft diet on the expression of Fos-ir cells in Pr5, PTg and SNc.

A: A schematic transmission pathway of oral sensation from the mouth to the SVZ. The principal sensory trigeminal nucleus (Pr5), which receive intraoral touch information via the trigeminal nerve, transmits to the pedunculopontine tegmental nucleus (PTg) via the thalamus [24], somatosensory cortex [25], and motor cortex [26]. Neurons of the PTg innervate to the substantia nigra pars compacta (SNc) [27], [28], [47], in which dopaminergic neurons innervate to the SVZ [29], [30]. The number of Fos-ir cells in 100 µm thickness in Figure 115 of the mouse atlas (lateral 1.68 mm) of the Pr5 (B), 100 µm thickness in Figure 111 of the mouse atlas (lateral 1.20 mm) of PTg (C), and 200 µm thickness from Figure 106 of the mouse atlas (lateral 0.60 mm) of SNc (D) to the lateral side of mice after the ingestion of a hard diet (black column), soft diet fed (white column) or no diet (gray column). n = 4 (white and gray column in B). n = 5 (C). n = 10 (black and gray column in D). n = 11 (white column in D). *: p<0.05; **: p<0.005.