FIG. 4.

Photomicrographs of matched coronal sections from the (A) N₄ and (B) T₄ groups located in the rostral part of the left somatosensory cortex (Paxinos Rat Brain Atlas: corresponding to Fig. #16; stereotaxic parameters: bregma 0.48 mm, interaural 9.48 mm). Sections were stained with a 1:2000 dilution of Fos antibody, and Fos-like immunoreactivity was visualized by the avidin–biotin complex method using Nickel peroxidase intensification. The darkly stained nuclei represent the nuclear expression of Fos-like immunoreactivity at 30 min following exposure to a hot plate shown at 5× magnification (scale = 400 μm). Greater cortical expression of Fos-like immunoreactivity occurred at 30 min after hot plate exposure in the T₄ group (B) compared with the N₄ group (A).