Modeling human methamphetamine use patterns in mice: chronic and binge methamphetamine exposure, reward function and neurochemistry

Different methamphetamine use patterns in human subjects may contribute to inconsistent findings regarding the effects of methamphetamine abuse on brain and behavior. The present study investigated whether human‐derived chronic and binge methamphetamine use patterns have differential effects on reward and neurochemistry in mice. Brain reward function in mice was evaluated during acute/prolonged withdrawal, and in response to methamphetamine challenge using the intracranial self‐stimulation procedure. Brain dopaminergic, serotonergic and glutamatergic neurochemistry was determined with high‐performance liquid chromatography. Chronic and binge regimens induced withdrawal‐related decreases in reward function that were more severe during the binge regimen during cycles 1–2. Despite large differences in methamphetamine dose, both regimens induced similar reward deficits during cycles 3–4. Neither methamphetamine regimen led to persistent alterations in the sensitivity to the reward‐enhancing effects of acute methamphetamine challenge. The binge regimen severely depleted striatal dopamine levels and increased brain glutamine levels. The chronic regimen had milder effects on striatal dopamine levels and altered cortical dopamine and serotonin levels. This work highlights that the magnitude of acute/prolonged withdrawal may not reflect amount or frequency of methamphetamine intake. In contrast, the array of underlying neurochemical alterations was methamphetamine regimen dependent. Thus, stratifying methamphetamine‐dependent individuals based on use pattern may help to cater therapeutic interventions more appropriately by targeting use pattern‐specific neurotransmitter systems. We examined human‐derived binge and chronic methamphetamine use patterns in mice. Both regimens induced a similar magnitude of reward deficits during withdrawal and methamphetamine‐challenge‐induced reward enhancement. The binge regimen depleted dopamine levels in the striatum and increased glutamine levels throughout the brain. The chronic regimen moderately decreased dopamine levels in the striatum and altered cortical dopamine and serotonin levels. This study demonstrates that aspects of reward and neurochemistry can be either independent or dependent on methamphetamine use parameters.