Wheel running alters serotonin (5-HT) transporter, 5-HT1A, 5-HT1B, and alpha 1b-adrenergic receptor mRNA in the rat raphe nuclei.
BACKGROUND
Altered serotonergic (5-HT) neurotransmission is implicated in the antidepressant and anxiolytic properties of physical activity. In the current study, we investigated whether physical activity alters factors involved in the regulation of central 5-HT neural activity.


METHODS
In situ hybridization was used to quantify levels of 5-HT transporter (5-HTT), 5-HT(1A), 5-HT(1B), and alpha(1b)-adrenergic receptor (alpha(1b) ADR) messenger ribonucleic acids (mRNAs) in the dorsal (DRN) and median raphe (MR) nuclei of male Fischer rats after either sedentary housing or 3 days, 3 weeks, or 6 weeks of wheel running.


RESULTS
Wheel running produced a rapid and lasting reduction of 5-HT(1B) mRNA in the ventral DRN. Three weeks of wheel running decreased 5-HTT mRNA in the DRN and MR and increased alpha(1b) ADR mRNA in the DRN. After 6 weeks of wheel running, 5-HTT mRNA remained reduced, but alpha(1b) ADR mRNA returned to sedentary levels. Serotonin(1A) mRNA was increased in the MR and certain DRN subregions after 6 weeks only.


CONCLUSIONS
Data suggest that the central 5-HT system is sensitive to wheel running in a time-dependent manner. The observed changes in mRNA regulation in a subset of raphe nuclei might contribute to the stress resistance produced by wheel running and the antidepressant and anxiolytic effects of physical activity.
Greenwood
Benjamin N
BN
Department of Integrative Physiology, University of Colorado, Boulder, Colorado 80309-0354, USA.
Foley
Teresa E
TE
Day
Heidi E W
HE
Burhans
Daniel
D
Brooks
Leah
L
Campeau
Serge
S
Fleshner
Monika
M
D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D001835:Body Weight / Q000502:physiology; D005786:Gene Expression Regulation / Q000502:physiology; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009043:Motor Activity / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011903:Raphe Nuclei / Q000033:anatomy & histology / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D044282:Receptor, Serotonin, 5-HT1A / Q000235:genetics / Q000378:metabolism*; D044302:Receptor, Serotonin, 5-HT1B / Q000235:genetics / Q000378:metabolism*; D018340:Receptors, Adrenergic, alpha-1 / Q000235:genetics / Q000378:metabolism*; D012420:Running; D050486:Serotonin Plasma Membrane Transport Proteins; D013997:Time Factors
C547718:Adra1b protein, rat; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D044302:Receptor, Serotonin, 5-HT1B; D018340:Receptors, Adrenergic, alpha-1; D050486:Serotonin Plasma Membrane Transport Proteins; C493232:Slc6a4 protein, rat; D044282:Receptor, Serotonin, 5-HT1A