Rise of CO2 in the air and in the blood elicits very negative moods in animals, including humans.

CO2 is a respiratory stimulant. But not for Paula. Paula seems to have a broken feedback ventilatory response to rising CO2 whether from exposure, exercise [which makes CO2 in the blood rise] or upper respiratory obstruction. Hypoventilation is her normal baseline ventilatory pattern at rest. Breathing is difficult for her and takes effort. Her lungs are normal. It seems to be some kind of mechanical problem She is not aware that her breathing is abnormal. . Strangely, she is usually fine, despite her hypoventilation. Until she is not. It takes a lot for her to not be fine. It doesn’t happen often. And when she is not fine, she responds emotionally with chronic anxiety, fear, and distress, the same as the rats exposed to CO2 described below. And she does not know why she feels this way.

Understanding rat emotional responses to CO2

Lucía Améndola1 and Daniel. M. Weary 1page1image3502711328page1image3502712464page1image3502713408Améndola and Weary Translational Psychiatry (2020)10:253 https://doi.org/10.1038/s41398-020-00936-w


The aim of this review is to summarize evidence regarding rat emotional experiences during carbon dioxide (CO2) exposure. The studies reviewed show that CO2 exposure is aversive to rats, and that rats respond to CO2 exposure with active and passive defense behaviors. Plasma corticosterone and bradycardia increased in rats exposed to CO2. As with anxiogenic drugs, responses to CO2 are counteracted by the administration of anxiolytics, SRIs, and SSRI’s. Human studies reviewed indicate that, when inhaling CO2, humans experience feelings of anxiety fear and panic, and that administration of benzodiazepines, serotonin precursors, and SSRIs ameliorate these feelings. In vivo and in vitro rat studies reviewed show that brain regions, ion channels, and neurotransmitters involved in negative emotional responses are activated by hypercapnia and acidosis associated with CO2 exposure. On the basis of the behavioral, physiological, and neurobiological evidence reviewed, we conclude that CO2 elicits negative emotions in rats.

So if a person is found to have hypoventilation, a reduced rate of breathing, and they feel chronically stressed, full of fear and continual panic, they are most likely suffering from hypercapnia respiratory failure and they do not know it.

The treatment for rats and for humans will be administration of benzodiazepines, serotonin precursors and SSRI’s as well as non invasive help to move air in and out of the body, strategies to help open and unblock the airway, and possibly antibiotics for general hidden infections.

Medical education will help the patient to avoid triggering situations [malnutrition, dehydration, overcrowded poorly ventilated spaces, etc…and the family should be alerted for times when the person cannot function and needs outside help.

to be continued………….


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