Paula, long term adaptation to hypercapnia

Neuroplasticity Underlying Adaptation to Long-Term Hypercapnia

The ventilation pattern is altered during long-term hypercapnia. The most common trend during long-term hypercapnia is a biphasic response consisting of an initial increase in ventilatory drive followed by a reduced response over the long term (Schaefer, 1963Schaefer et al., 1963Clark et al., 1971Guillerm and Radziszewski, 1979Jennings and Davidson, 1984Burgraff et al., 20182019) […It is well established that acute hypercapnia causes an increase in the ventilatory drive by peripherally and centrally mediated chemoreflex systems (Forster and Smith, 2010Smith et al., 2010).”………

……..” Hypercapnia is a respiratory stressor that occurs in many disease (e.g., COPD, OHS, OSA, etc.) or non-disease conditions (e.g., miners, submarines, scuba divers, astronauts, hibernating animals, deep sea creatures, etc.). While the physiologic mechanism that underlies the central respiratory chemoreflex response to long term hypoxia is well established, the mechanisms underlying central neuroplastic changes that occur during long-term hypercapnia are yet to be clarified.” ORIGINAL RESEARCH ARTICLE Front. Neurosci., 13 December 2019 | Adaptation of Respiratory-Related Brain Regions to Long-Term Hypercapnia: Focus on Neuropeptides in the RTN. Ayse Sumeyra Dereli1Zarwa Yaseen1Pascal Carrive2 and Natasha N. Kumar1*

Paul and I think that Paula breaths only 1.5 litres of air at rest when awake [instead of the normal 5-8 litres of air because her ventilation pattern has been altered during long term hypercapnia. Chronic hypercapnia, I am told will not cause symptoms. The person will adapt to chronic hypercapnia by adjusting their metabolism, if they are otherwise healthy – like Paula.

If Paula becomes sick, however, with COV-ID or with another significant virus, she may have trouble recovering because of her reduced response to hypercapnia and her inability raising her respiratory rate even during an acute on chronic attack.

……….The broader * LC-NE system governs an ‘alarm system’ response to stress (Lanius et al., 2017) across species.………, recent advances in high-resolution 7-T magnetic resonance imaging and computational modeling approaches are starting to provide new insights into locus coeruleus characteristics. * locus coeruleus-norepinephrine (LC-NE) Brain Neurosci Adv. 2020 Jan-Dec; 4: 2398212820930321. doi: 10.1177/2398212820930321 The role of the locus coeruleus in the generation of pathological anxiety. Laurel S. Morris,1 Jordan G. McCall,2 Dennis S. Charney,3 and  James W. Murrough1

“The activation of these [LC] neurons in Hypercapnia, generally associated with increased apprehension in man, is consistent with the notion that the LC may serve as an alarm system in the brain.” Brain Res. 1981 Oct 19;222(2):373-81. doi: 10.1016/0006-8993(81)91040-4. Hypercapnia and hypoxia: chemoreceptor-mediated control of locus coeruleus neurons and splanchnic, sympathetic nerves M ElamT YaoP ThorénT H Svensson


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