title: Nucleus accumbens neuronal maturation differences in young rats bred for low versus high voluntary running behaviour.
abstract: We compared the nucleus accumbens (NAc) transcriptomes of generation 8 (G8), 34-day-old rats selectively bred for low (LVR) versus high voluntary running (HVR) behaviours in rats that never ran (LVR(non-run) and HVR(non-run)), as well as in rats after 6 days of voluntary wheel running (LVR(run) and HVR(run)). In addition, the NAc transcriptome of wild-type Wistar rats was compared. The purpose of this transcriptomics approach was to generate testable hypotheses as to possible NAc features that may be contributing to running motivation differences between lines. Ingenuity Pathway Analysis and Gene Ontology analyses suggested that 'cell cycle'-related transcripts and the running-induced plasticity of dopamine-related transcripts were lower in LVR versus HVR rats. From these data, a hypothesis was generated that LVR rats might have less NAc neuron maturation than HVR rats. Follow-up immunohistochemistry in G9-10 LVR(non-run) rats suggested that the LVR line inherently possessed fewer mature medium spiny (Darpp-32-positive) neurons (P < 0.001) and fewer immature (Dcx-positive) neurons (P < 0.001) than their G9-10 HVR counterparts. However, voluntary running wheel access in our G9-10 LVRs uniquely increased their Darpp-32-positive and Dcx-positive neuron densities. In summary, NAc cellularity differences and/or the lack of running-induced plasticity in dopamine signalling-related transcripts may contribute to low voluntary running motivation in LVR rats.
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Roberts
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.
authors.forename: Ryan G
authors.initials: RG
authors.lastname: Toedebusch
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia, MO, USA.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Wells
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Company
authors.affiliation: Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA.
authors.forename: Jacob D
authors.initials: JD
authors.lastname: Brown
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.
authors.forename: Clayton L
authors.initials: CL
authors.lastname: Cruthirds
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Heese
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.
authors.forename: Conan
authors.initials: C
authors.lastname: Zhu
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.
authors.forename: George E
authors.initials: GE
authors.lastname: Rottinghaus
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Childs
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, USA boothf@missouri.edu.
authors.forename: Frank W
authors.initials: FW
authors.lastname: Booth
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D000089662:Doublecortin Protein; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D006801:Humans; D009043:Motor Activity / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D009714:Nucleus Accumbens / Q000166:cytology / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012420:Running / Q000502:physiology*; D014836:Volition / Q000502:physiology*
chemical_list: C000714848:Dcx protein, rat; D000089662:Doublecortin Protein; D009419:Nerve Tissue Proteins