Amphetamine-induced locomotion and gene expression are altered in BDNF heterozygous mice.
Administration of amphetamine overstimulates medium spiny neurons (MSNs) by releasing dopamine and glutamate from afferents in the striatum. However, these afferents also release brain-derived neurotrophic factor (BDNF) that protects striatal MSNs from overstimulation. Intriguingly, all three neurochemicals increase opioid gene expression in MSNs. In contrast, striatal opioid expression is less in naive BDNF heterozygous (BDNF(+/-)) vs. wild-type (WT) mice. This study was designed to determine whether partial genetic depletion of BDNF influences the behavioral and molecular response to an acute amphetamine injection. An acute injection of amphetamine [5 mg/kg, intraperitoneal (i.p.)] or saline was administered to WT and BDNF(+/-) mice. WT and BDNF(+/-) mice exhibited similar locomotor activity during habituation, whereas BDNF(+/-) mice exhibited more prolonged locomotor activation during the third hour after injection of amphetamine. Three hours after amphetamine injection, there was an increase of preprodynorphin mRNA in the caudate putamen and nucleus accumbens (Acb) and dopamine D(3) receptor mRNA levels were increased in the Acb of BDNF(+/-) and WT mice. Striatal/cortical trkB and BDNF, and mesencephalic tyrosine hydroxylase mRNA levels were only increased in WT mice. These results indicate that BDNF modifies the locomotor responses of mice to acute amphetamine and differentially regulates amphetamine-induced gene expression.
Saylor
A J
AJ
Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA.
McGinty
J F
JF
D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000661:Amphetamine / Q000494:pharmacology*; D019969:Amphetamine-Related Disorders / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects / Q000235:genetics*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000235:genetics; D004399:Dynorphins / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000235:genetics; D006185:Habituation, Psychophysiologic / Q000187:drug effects / Q000235:genetics; D006579:Heterozygote; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009043:Motor Activity / Q000187:drug effects* / Q000235:genetics; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D011498:Protein Precursors / Q000235:genetics; D020813:Receptor, trkB / Q000235:genetics; D050637:Receptors, Dopamine D3 / Q000235:genetics; D013997:Time Factors
D018759:Adrenergic Uptake Inhibitors; D019208:Brain-Derived Neurotrophic Factor; D011498:Protein Precursors; D050637:Receptors, Dopamine D3; C036448:pre-prodynorphin; D004399:Dynorphins; D000661:Amphetamine; D020813:Receptor, trkB