Fig. 9.

Low-power transmission electron micrograph from the cortex (upper panel) and thalamus (lower panel) showing neuronal nuclear (a, c, e) and axonal changes (b, d, f) in control (a, b), METH-23° C (c, d) and METH-29° C (e, f) groups. The neuronal nucleus in control rat shows a smooth nuclear envelop with dark granular karyoplasm containing a central nucleolus (a, arrow). The nerve cell cytoplasm is compact and condensed without any vacuoles. On the other hand, less electron-dense karyoplasm with an eccentric nucleolus showing degenerative changes is seen in the METH-23°C group (c, arrow). The nuclear membrane showed irregular foldings and vacuolation (*) in the neuropil including cytoplasm. These changes in the cell nucleus were much more aggravated in rat treated with METH at 29°C (e); degeneration of nuclear membrane and surrounding neurnal cytoplasm is clearly evident in this slice. The nucleolus is further degenerated (arrow) and became more eccentric (e). Bar: a–c = 1 µm. Axonal changes in the thalamus of METH-treated rats at 23°C (d) show profound myelin vesiculation (arrow) and edematous swelling (*, d). These changes were stronger in rats treated with METH at 29° C (f). In this group, the myelin vesiculation (arrows) and degeneration of axons were clearly evident (*, f). On the other hand, normal rat exhibited a compact neuropil with normal myelinated axons (arrow heads, b). Signs of vacuolation and edema are largely absent in control group (a, b). Bars: b = 1500 nm, d = 800 nm; f = 600 nm.