title: Somatosensory Brain Function and Gray Matter Regional Volumes Differ According to Exercise History: Evidence from Monozygotic Twins.
abstract: Associations between long-term physical activity and cortical function and brain structure are poorly known. Our aim was to assess whether brain functional and/or structural modulation associated with long-term physical activity is detectable using a discordant monozygotic male twin pair design. Nine monozygotic male twin pairs were carefully selected for an intrapair difference in their leisure-time physical activity of at least three years duration (mean age 34 ± 1 years). We registered somatosensory mismatch response (SMMR) in EEG to electrical stimulation of fingers and whole brain MR images. We obtained exercise history and measured physical fitness and body composition. Equivalent electrical dipole sources of SMMR as well as gray matter (GM) voxel counts in regions of interest indicated by source analysis were evaluated. SMMR dipolar source strengths differed between active and inactive twins within twin pairs in postcentral gyrus, medial frontal gyrus and superior temporal gyrus and in anterior cingulate (AC) GM voxel counts differed similarly. Compared to active twins, their inactive twin brothers showed greater dipole strengths in short periods of the deviant-elicited SMMR and larger AC GM voxel counts. Stronger activation in early unattended cortical processing of the deviant sensory signals in inactive co-twins may imply less effective gating of somatosensory information in inactive twins compared to their active brothers. Present findings indicate that already in 30's long-term physical activity pattern is linked with specific brain indices, both in functional and structural domains.
authors.affiliation: Department of Health Sciences, University of Jyväskylä, Rautpohjankatu 8, 40014, Jyväskylä, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Hautasaari
authors.affiliation: School of Electrical Engineering, University of Belgrade, Belgrade, Serbia.|Tecnalia Serbia Ltd., Belgrade, Serbia.
authors.forename: Andrej M
authors.initials: AM
authors.lastname: Savić
authors.affiliation: Department of Psychology, University of Jyväskylä, Jyväskylä, Finland.
authors.forename: Otto
authors.initials: O
authors.lastname: Loberg
authors.affiliation: Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
authors.forename: Eini
authors.initials: E
authors.lastname: Niskanen
authors.affiliation: Department of Public Health, University of Helsinki, Helsinki, Finland.|National Institute for Health and Welfare, Helsinki, Finland.|Institute for Molecular Medicine (FIMM), University of Helsinki, Helsinki, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kaprio
authors.affiliation: Department of Health Sciences, University of Jyväskylä, Rautpohjankatu 8, 40014, Jyväskylä, Finland.
authors.forename: Urho M
authors.initials: UM
authors.lastname: Kujala
authors.affiliation: Department of Health Sciences, University of Jyväskylä, Rautpohjankatu 8, 40014, Jyväskylä, Finland. ina.tarkka@jyu.fi.
authors.forename: Ina M
authors.initials: IM
authors.lastname: Tarkka
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D066128:Gray Matter / Q000033:anatomy & histology* / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009929:Organ Size / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*; D014430:Twins, Monozygotic
keywords: Brain electrophysiology; Brain structure; Mismatch negativity; Physical activity; Somatosensory cortex; Twin research