title: Exercise-induced behavioral recovery and neuroplasticity in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned mouse basal ganglia.
abstract: Physical activity has been shown to be neuroprotective in lesions affecting the basal ganglia. Using a treadmill exercise paradigm, we investigated the effect of exercise on neurorestoration. The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model provides a means to investigate the effect of exercise on neurorestoration because 30-40% of nigrostriatal dopaminergic neurons survive MPTP lesioning and may provide a template for neurorestoration to occur. MPTP-lesioned C57 BL/6J mice were administered MPTP (four injections of 20 mg/kg free-base, 2 hr apart) or saline and divided into the following groups: (1). saline; (2). saline + exercise; (3). MPTP; and (4) MPTP + exercise. Mice in exercise groups were run on a motorized treadmill for 30 days starting 4 days after MPTP lesioning (a period after which MPTP-induced cell death is complete). Initially, MPTP-lesioned + exercise mice ran at slower speeds for a shorter amount of time compared to saline + exercise mice. Both velocity and endurance improved in the MPTP + exercise group to near normal levels over the 30-day exercise period. The expression of proteins and genes involved in basal ganglia function including the dopamine transporter (DAT), tyrosine hydroxylase (TH), and the dopamine D1 and D2 receptors, as well as alterations on glutamate immunolabeling were determined. Exercise resulted in a significant downregulation of striatal DAT in the MPTP + exercise compared to MPTP nonexercised mice and to a lesser extent in the saline + exercised mice compared to their no-exercise counterparts. There was no significant difference in TH protein levels between MPTP and MPTP + exercise groups at the end of the study. The expression of striatal dopamine D1 and D2 receptor mRNA transcript was suppressed in the saline + exercise group; however, dopamine D2 transcript expression was increased in the MPTP + exercise mice. Immunoelectron microscopy indicated that treadmill exercise reversed the lesioned-induced increase in nerve terminal glutamate immunolabeling seen after MPTP administration. Our data demonstrates that exercise promotes behavioral recovery in the injured brain by modulating genes and proteins important to basal ganglia function.
authors.affiliation: Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California 90033, USA.
authors.forename: Beth E
authors.initials: BE
authors.lastname: Fisher
authors.forename: Giselle M
authors.initials: GM
authors.lastname: Petzinger
authors.forename: Kerry
authors.initials: K
authors.lastname: Nixon
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Hogg
authors.forename: Samuel
authors.initials: S
authors.lastname: Bremmer
authors.forename: Charles K
authors.initials: CK
authors.lastname: Meshul
authors.forename: Michael W
authors.initials: MW
authors.lastname: Jakowec
mesh_terms: D000818:Animals; D001479:Basal Ganglia / Q000201:enzymology / Q000378:metabolism* / Q000503:physiopathology; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D050483:Dopamine Plasma Membrane Transport Proteins; D020267:MPTP Poisoning / Q000378:metabolism / Q000503:physiopathology* / Q000517:prevention & control*; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D026901:Membrane Transport Proteins / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000379:methods*; D014446:Tyrosine 3-Monooxygenase / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493215:Slc6a3 protein, mouse; D014446:Tyrosine 3-Monooxygenase