Updated Cerebrovascular Physiology Links – 17/12/2014

I have updated the Cerebrovascular Physiology Links. You will now see a link to the lab of Dr Hélène Girouard from Université de Montréal. Her research interests are related to cerebrovascular pharmacology, neurovascular coupling and interactions between astrocytes and blood vessels.

In addition, I have added a new section entitled “Theses”, where you will find MSc/PhD theses discussing cerebrovacular physiology related issues. If you would like to have your thesis added to this new section, just let me know !

Cerebrovascular physiology – article alert #91

Migraine and brain blood flow

472- Migraine and cerebral blood flow in the general population – Loehrer et al.

Orthostatic hypotension and the brain

473- Influence of nocturnal and daytime sleep on initial orthostatic hypotension – Lewis et al.

Cerebrovascular regulation

474- Rapid pressure-to-flow dynamics of cerebral autoregulation induced by instantaneous changes of arterial CO2 – Liu et al.

475- Relationship Between Cerebral Blood Flow and Blood Pressure in Long-Term Heart Transplant Recipients – Smirl et al.

476- Cerebral autoregulation is minimally influenced by the superior cervical ganglion in two- week-old lambs, and absent in preterm lambs immediately following delivery – Czynski et al.

Exercise/fitness and the brain

477- Effects of interval training on cognitive functioning and cerebral oxygenation in obese patients: A pilot study – Drigny et al.

478- Improved cerebral oxygenation response and executive performance as a function of cardiorespiratory fitness in older women: a fNIRS study – Albinet et al.

LVAD and the brain

479- Effect of pulsatile and nonpulsatile flow on cerebral perfusion in patients with left ventricular assist devices – Cornwell et al.

Diabetes and the brain

480- Cerebral perfusion in insulin resistance and type 2 diabetes – Rusinek et al.

Nitrate and the brain

481- Dietary nitrate facilitates an acetazolamide-induced increase in cerebral blood flow during visual stimulation – Aamand et al.

Cerebrovascular reactivity

482- Factors affecting the determination of cerebrovascular reactivity – Regan et al.

Cerebrovascular physiology – article alert #90

Orthostatic tolerance and the brain

462- Impact of hypocapnia and cerebral perfusion on orthostatic tolerance – Lewis et al.

463- Phenylephrine Alteration of Cerebral Blood Flow During Orthostasis; Effect on N-Back Performance in Chronic Fatigue Syndrome – Medow et al.

Cerebral autoregulation

464- Does the static cerebral autoregulatory plateau have a finite slope in healthy preterm neonates? Toksvang and Berg

465- Dynamic cerebral autoregulation after bed rest: effects of volume loading and exercise countermeasures – Jeong et al.

466- Integrative physiological and computational approaches to understand autonomic control of cerebral autoregulation – Tan and Taylor

467- Arterial pressure above the upper cerebral autoregulation limit during cardiopulmonary bypass is associated with postoperative delirium – Hori et al.

468- Shoulder Surgery in the Beach Chair Position Is Associated with Diminished Cerebral Autoregulation but No Differences in Postoperative Cognition or Brain Injury Biomarker Levels Compared with Supine Positioning: The Anesthesia Patient Safety Foundation Beach Chair Study – Laflam et al.

Exercise and the brain

469- The effect of changes in cerebral blood flow on cognitive function during exercise – Ogoh et al.

470- Acute exercise stress reveals cerebrovascular benefits associated with moderate gains in cardiorespiratory fitness – Brugniaux et al.

Traumatic brain injury

471- Cerebrovascular regulation, exercise, and mild traumatic brain injury – Tan et al.

On the persistence of a dogma in cerebrovascular physiology

When I received the latest issue of Physiology on my desk yesterday, I was pretty excited to read this particular review about physiological responses to acute exercise and training in different organs! Wow, there was even a section related to the brain ! And it was the first section !

So, I decided to bring that issue of Physiology into the gym in order to read it while exercising on the cycle ergometer…and then…boom:

“Studies in humans and animals have shown that brain blood flow remains largerly unchanged in response to acute exercise”

On top of everything, this sentence started the section related to the brain…

I was suddenly not interested in reading the remaining of that review anymore…

Have a look at these papers (and it’s far from the complete list !) about the impact of acute exercise and cerebral blood flow/cerebral blood flow velocity:

  • Jørgensen LG et al. J Appl Physiol 1992
  • Moraine JJ et al. Eur J Appl Physiol Occup Physiol 1993
  • Secher NH et al. J Appl Physiol 2008
  • Subudhi AW et al. Am J Physiol Heart Circ Physiol 2008
  • Ogoh S Med Sci Sports Exerc 2008
  • Ogoh S and Ainslie PN J Appl Physiol 2009
  • Ogoh S and Ainslie PN Exerc Sport Sci Rev 2009
  • Smith KJ et al. Respiratory Physiology & Neurobiology 2012
  • Brugniaux JV et al. J Cereb Blood Flow Metab 2014
  • Smith KJ et al. J Physiol (In press) 2014

Recent literature have shown consistent increases in cerebral blood flow in response to exercise (with exercise intensities up to around 60-70% maximal exercise).

So please, stop perpetuating this old dogma ! Especially without any nuances !

Interesting podcast over at Journal of Applied Physiology

A few weeks ago, I have posted an article alert regarding two papers published in J Appl Physiol challenging the assumption that the diameter of the middle cerebral artery remains constant in response to changes in hypo- and hypercapnia.

You can now listen to a podcast where Kevin Shoemaker (Senior author on Covervale et al. paper), Jasper Verbree (First author of the second paper) and Phil Ainslie (who published an editorial related to these two manuscripts) further discuss the results of these papers.  Really interesting !

I have also added a link to this podcast in the Cerebrovascular Physiology links section of the blog.

One picture is worth a thousand words #1

Since the publication of a manuscript is usually the final step of a research project that may take months and even years to complete, I thought that it would be interesting to present “behind the scene” pictures in this new section entitled “One picture is worth a thousand words”.

I will name that first picture Rigshospitalet-style. My interest for the brain started in that research lab in Copenhagen…good memories !

Diapositive2Research in my lab should look like this soon…indeed…remember this

If you have “Behind the scene” moments you would like to share, just let me know and I will post it in this new section !

Cerebral oxygenation in health and disease: the end…or is it the beginning ??

A few months ago, I got the opportunity to organize a research topic, which represents a collection of articles that addresses a specific research area, to be published in the journal Frontiers in Physiology. Phil Ainslie, Niels Secher and I proposed the topic entitled Cerebral oxygenation in health and disease, which was subsequently accepted by the journal. The rest is history !

Our appointment as guest editors for this research topic comes to an end with the publication of our editorial, which presents the 18 papers (original research, review of the literature, opinion letter) included in this topic.

I would like to thank my colleagues Phil and Niels for their invaluable help, as well as all the contributors to this important research topic. As mentioned at the end of our editorial:

This research topic covers a wide range of exciting but at the same time unsettled issues related to cerebrovascular physiology with a focus on cerebral oxygenation. We hope that this e-book represents an opportunity to improve understanding in this field, as well as provide directions for further research

Although the research topic is pretty easy to access online, I have updated the Cerebrovascular Physiology links of this blog.

Go have a read and let me know what you think !