Effect of a neurotoxic dose regimen of (+)-methamphetamine on behavior, plasma corticosterone, and brain monoamines in adult C57BL/6 mice.
BACKGROUND
In rats, neurotoxic doses of methamphetamine (MA) induce astrogliosis, long lasting monoamine reductions, reuptake transporter down-regulation, and learning impairments.


OBJECTIVE
We tested whether comparable effects occur in C57BL/6 mice.


METHODS
C57BL/6 mice were treated with 10mg/kgs.c.x4 MA on a single day and evaluated at various intervals thereafter.


RESULTS
The neurotoxic dose regimen of MA caused the predicted acute hyperthermia and increased striatal glial fibrillary acidic protein and reduced neostriatal dopamine. The MA-treated mice were hypoactive 24h later but not 48h later. MA-treated mice also showed exaggerated initial hyperactivity after a pharmacological dose of MA used to stimulate locomotion followed by a later phase of hypoactivity compared to saline-treated mice. No differences were observed on learning or memory tests (novel object recognition, egocentric, or spatial learning/memory). MA-treated mice showed a trend toward increased prepulse inhibition but not baseline acoustic startle reactivity. After testing, MA-treated mice showed reduced neostriatal dopamine and increased basal plasma corticosterone.


CONCLUSIONS
A neurotoxic/binge regimen of MA in mice that produces the typical pattern of neurotoxic changes to those seen in rats, results in few behavioral changes. This may limit the utility of C57BL/6 mice for modeling the cognitive and behavioral effects described in human MA users who show such changes even after prolonged abstinence.
Grace
Curtis E
CE
Division of Neurology, Dept. of Pediatrics, Cincinnati Children's Research Foundation, Cincinnati, Ohio, United States.
Schaefer
Tori L
TL
Herring
Nicole R
NR
Graham
Devon L
DL
Skelton
Matthew R
MR
Gudelsky
Gary A
GA
Williams
Michael T
MT
Vorhees
Charles V
CV
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D015306:Biogenic Monoamines / Q000378:metabolism*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003345:Corticosterone / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008694:Methamphetamine / Q000737:chemistry / Q000633:toxicity*; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects; D020258:Neurotoxicity Syndromes / Q000097:blood / Q000209:etiology* / Q000378:metabolism / Q000523:psychology; D055139:Sensory Gating / Q000187:drug effects
D015306:Biogenic Monoamines; D005904:Glial Fibrillary Acidic Protein; D008694:Methamphetamine; D003345:Corticosterone