Posted: May 10, 2018 4:15 pm
by zoon
WiggleHead wrote:I remember around 2010 or 2013 a doctor did this cruel study on mice by injecting gentamicin (an antibiotic that destroys the vestibular system) into mice's ears. He then gave them a gas that made them fall asleep. The mice without vestibular systems died in their sleep, while the ones that weren't injected with gentamicin survived and did not stop breathing.

The doctor then concluded that the cause of sudden infant death syndrome (in humans) was vestibular/inner ear damage, because the vestibular system senses CO2 and is the organ responsible for the drive to breathe, and NOT the brainstem/medulla as is popularly believed. I remember there were several news sites covering the study and that doctor's conclusions, and one of them was entitled ''your lungs listen to your ears'', and the article said the ears are now considered an extremely important part of the respiratory system.

Can anyone help point out any problems in this theory? I tried looking for articles but it seems like most of them have been removed, I managed to find one though http://www.kidspot.com.au/baby/real-lif ... a38d74c71f

Original 2011 article - https://www.sciencedirect.com/science/a ... 2210015253

2013 followup article - https://www.sciencedirect.com/science/a ... 2213007550

2016 followup article - https://www.sciencedirect.com/science/a ... 2216304365

Without having read the articles carefully, I don't think the authors were claiming that the brainstem/medulla is not also involved in controlling breathing. Quoting from the website (here) of the Center for Integrative Brain Research in Seattle, where I think these experiments were carried out:
The seemingly simple task of breathing belies the deceptively complex control system our body uses for respiration. In day to day functioning, respiratory networks need to adapt to external changes in the environment, to our own movements, behaviors, and state of arousal. In order to properly adapt, the respiratory network can be altered by neuromodulators as well as peripheral and central chemoreceptors that monitor the pO2 and pCO2 levels in the blood.

Presumably, on their hypothesis, the medulla/brainstem receptors would be included among the central ones they are referring to, and the inner ear receptors would be peripheral. If both are needed for an adequate response to dangerous blood levels of carbon dioxide or oxygen during sleep, the contribution of the inner ear receptors could have been missed by earlier experimenters who studied the receptors in the centre of the brain?