"Bath Salts" and methamphetamine have a different toxicological profile?

There have been a number of news reports recently about people who display abnormal aggression while using "bath salts".  The putative active ingredient in these preparations is mephedrone, a combination of methamphetamine and cathinone.  While methamphetamine is neurotoxic to the terminal button of striatal neurons, a report in The Journal of Neurochemistry suggests that mephedrone lacks methamphetamine's impact in this model.   Despite the similarities between mephedrone and methamphetamine, mephedrone does not produce methamphetamine's change in dopamine, dopamine transporter, or tyrosine hydroxylase.

Reference - Angoa-Perez et al. (2012). Mephedrone, an abused psychoactive component of 'bath salts' and methamphetamine congener, does not cause neurotoxicity to dopamine nerve endings of the striatum  J Neurosci 120(6): 1097

Donepezil (Aricept) blocks cocaine's, but not methamphetamine's, effects

Donepezil is used to manage the early symptoms of Alzheimer's Disease and is available as the Aricept preparation.  It is a cholinesterase inhibitor, and increases acetylcholine levels in brain.  Our lab group recently reviewed a paper by Takamatsu and colleages on donepezil's efficacy to block the conditioned reinforcing (place preference) and locomotor activating properties of cocaine and methamphetamine in mice.  While it diminished the effects of cocaine, it was ineffective to alter methamphetamine's effects in this study.  Considering the efficacy of other cholinergic ligands (e.g., lobeline) to alter methamphetamine's effects, these findings were surprising to us.

Reference - Takamatus Y. et al. (2006) Differential effects of donepezil on methamphetamine and cocaine depedencies.  Ann NY Acad Sci 1074: 418

Methamphetamine place preference

Our laboratory at the University of Missouri is working to develop a place preference assay to evaluate the conditioned-rewarding properties of methamphetamine in mice.  We were able to develop a cocaine place preference procedure, but have been struggling with methamphetamine.  Any suggestions would be appreciated!