Fig. 4. Photomicrographs illustrating the striking effects of cocaethylene on brain IEGs. Cocaethylene is derived from the combined ingestion of cocaine and ethanol. This neuroactive metabolite induces the expression of Fos-like protein in dopaminoreceptive neurons of the caudate putamen (cdP). Top, Schematic illustration drawn through a comparable level of the cdP, where induction of Fos-like immunoreactivity is persistently observed after acute cocaethylene treatment. Middle, Representative photomicrograph through the cdP of a rat injected with sterile NaCl. Note the relative absence of Fos-like protein on medium-sized spiny neurons. Bottom, Representative photomicrograph through the cdP of a rat injected with cocaethylene (20 mg/kg). Note the distribution pattern and relative strength of the transcription factor protein. Asterisk indicates unreactive myelinated bundles of corticofugal fibers coursing through the cdP.
