Fig. 3.

Methamphetamine (METH)-treated mice with RESDs have acidophilic neurons in the left piriform cortex (C) that are morphologically distinct from apoptotic neurons (D and E). The control mouse and one without RESDs have normal neuronal nuclei (A and B). C shows acidophilic neurons with shrunken, condensed nuclei and eosinophilic cytoplasm. By way of comparison, (D) and (E) show apoptotic neurons in the retrosplenial cortex of postnatal day 8 (P8) rat pups. In (D) the apoptotic neuron, stained with H&E, shows large, round chromatin clumps that are basophilic; the cytoplasm is eosinophilic. In (E) the apoptotic neuron is TUNEL-positive (yellowish brown), with large, round chromatin clumps that are TUNEL-negative but are stained with the counterstain, methyl green. The double-stranded DNA fragments stained with TUNEL spill out into the entire cell body because the nuclear membrane is disrupted relatively early in apoptotic neurons. The scale bars in (A) and (E) are 10 μm and in (D) the scale bar is 5 μm.