PMID- 28228584
OWN - NLM
STAT- MEDLINE
DCOM- 20170920
LR  - 20181129
IS  - 1522-1598 (Electronic)
IS  - 0022-3077 (Print)
IS  - 0022-3077 (Linking)
VI  - 117
IP  - 4
DP  - 2017 Apr 1
TI  - High cardiorespiratory fitness in early to late middle age preserves the cortical 
      circuitry associated with brain-heart integration during volitional exercise.
PG  - 1831-1840
LID - 10.1152/jn.00592.2016 [doi]
AB  - This study tested the hypothesis that high cardiorespiratory fitness (peak oxygen 
      uptake) preserves the cortical circuitry associated with cardiac arousal during 
      exercise in middle- to older-aged individuals. Observations of changes in heart 
      rate (HR) and in cortical blood oxygenation level-dependent (BOLD) images were 
      made in 52 healthy, active individuals (45-73 yr; 16 women, 36 men) across a 
      range of fitness (26-66 ml.kg(-1).min(-1)). Seven repeated bouts of isometric 
      handgrip (IHG) at 40% maximal voluntary contraction force were performed with 
      functional magnetic resonance imaging at 3 T, with each contraction lasting 20 s 
      and separated by 40 s of rest. HR responses to IHG showed high variability across 
      individuals. Linear regression revealed that cardiorespiratory fitness was not a 
      strong predictor of the HR response (r(2) = 0.09). In a region-of-interest 
      analysis both the IHG task and the HR time course correlated with increased 
      cortical activation in the bilateral insula and decreased activation relative to 
      baseline in the anterior and posterior cingulate and medial prefrontal cortex 
      (MPFC). t-Test results revealed greater deactivation at the MPFC with higher 
      fitness levels beyond that of guideline-based activity. Therefore, whereas high 
      cardiorespiratory fitness failed to affect absolute HR responses to IHG in this 
      age range, a select effect was observed in cortical regions known to be 
      associated with cardiovascular arousal.NEW & NOTEWORTHY Our first observation 
      suggests that fitness does not strongly predict the heart rate (HR) response to a 
      volitional handgrip task in middle- to older-aged adults. Second, the BOLD 
      response associated with the handgrip task, and with the HR time course, was 
      associated with response patterns in the cortical autonomic network. Finally, 
      whereas high cardiorespiratory fitness failed to affect absolute HR responses to 
      isometric handgrip in this age range, a select effect was observed in cortical 
      regions known to be associated with cardiovascular arousal, beyond that achieved 
      through healthy active living.
CI  - Copyright (c) 2017 the American Physiological Society.
FAU - Wood, Katelyn N
AU  - Wood KN
AD  - Neurovascular Research Laboratory, School of Kinesiology, The University of 
      Western Ontario, London, Ontario, Canada; and.
FAU - Luchyshyn, Torri A
AU  - Luchyshyn TA
AD  - Neurovascular Research Laboratory, School of Kinesiology, The University of 
      Western Ontario, London, Ontario, Canada; and.
FAU - Shoemaker, J Kevin
AU  - Shoemaker JK
AD  - Neurovascular Research Laboratory, School of Kinesiology, The University of 
      Western Ontario, London, Ontario, Canada; and kshoemak@uwo.ca.
AD  - Department of Physiology and Pharmacology, The University of Western Ontario, 
      London, Ontario, Canada.
LA  - eng
GR  - 217532/CIHR/Canada
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20170222
PL  - United States
TA  - J Neurophysiol
JT  - Journal of neurophysiology
JID - 0375404
RN  - S88TT14065 (Oxygen)
SB  - IM
MH  - Aged
MH  - Blood Pressure/physiology
MH  - Brain/*diagnostic imaging/*physiology
MH  - Brain Mapping
MH  - Cardiorespiratory Fitness/*physiology
MH  - Electrocardiography
MH  - Exercise/*physiology
MH  - Exercise Test
MH  - Female
MH  - Hand Strength
MH  - Heart Rate/*physiology
MH  - Humans
MH  - Image Processing, Computer-Assisted
MH  - Linear Models
MH  - Magnetic Resonance Imaging
MH  - Male
MH  - Middle Aged
MH  - Oxygen/blood
MH  - Volition/physiology
PMC - PMC5390284
OTO - NOTNLM
OT  - age
OT  - cardiorespiratory fitness
OT  - cortical autonomic network
OT  - handgrip exercise
OT  - medial prefrontal cortex
EDAT- 2017/02/24 06:00
MHDA- 2017/09/21 06:00
PMCR- 2018/04/01
CRDT- 2017/02/24 06:00
PHST- 2016/07/22 00:00 [received]
PHST- 2017/02/03 00:00 [revised]
PHST- 2017/02/21 00:00 [accepted]
PHST- 2017/02/24 06:00 [pubmed]
PHST- 2017/09/21 06:00 [medline]
PHST- 2017/02/24 06:00 [entrez]
PHST- 2018/04/01 00:00 [pmc-release]
AID - jn.00592.2016 [pii]
AID - JN-00592-2016 [pii]
AID - 10.1152/jn.00592.2016 [doi]
PST - ppublish
SO  - J Neurophysiol. 2017 Apr 1;117(4):1831-1840. doi: 10.1152/jn.00592.2016. Epub 
      2017 Feb 22.