Characterizing cortical neuron injury with Fluoro-Jade labeling after a neurotoxic regimen of methamphetamine.

We used Fluoro-Jade, a recently-developed fluorescent indicator of neuronal damage, to identify neurons injured 1-21 days after repeated injections of methamphetamine (m-AMPH) or saline. The m-AMPH-treated rats showed Fluoro-Jade positive neurons in parietal cortex (layers III and IV) and had less striatal tyrosine hydroxylase immunoreactivity than did saline-injected controls. Fluoro-Jade positive neurons were greatest in number 3 days post-treatment; some fluorescent neurons displayed bud-like surface protrusions. These observations support the hypothesis that certain neocortical neurons degenerate after m-AMPH.