PMC:6194691 / 169024-170050 JSONTXT

{"project":"MyTest","denotations":[{"id":"30340614-27799072-30706539","span":{"begin":1023,"end":1024},"obj":"27799072"}],"namespaces":[{"prefix":"_base","uri":"https://www.uniprot.org/uniprot/testbase"},{"prefix":"UniProtKB","uri":"https://www.uniprot.org/uniprot/"},{"prefix":"uniprot","uri":"https://www.uniprot.org/uniprotkb/"}],"text":"In principle this can be done by feedback control in which increased concentration somehow modifies the mechanism of elimination to increase the clearance, e.g. by recruiting more transporters. To some extent this occurs with CO2. Increased pCO2 is associated with lower pH and stimulation of cerebral blood flow, which washes away the excess CO2 (see Sect. 5.2), i.e. increased pCO2 increases the clearance for CO2. However, feedback control still requires that there be a change in the concentration to stimulate and maintain the process (see Fig. 24).\nFig. 24 Diagram illustrating possible schemes for neurovascular coupling, i.e. regulation of blood flow changes associated with nerve activity. Two forms of control are shown, a simple feedback based on the signal to be regulated, e.g. pCO2, and b feedback plus feed-forward. The feed-forward element, signal2, in b, possibly from astrocytes, allows blood flow to increase with smaller changes in the primary quantity to be regulated, signal1\n(Figure reproduced from [4])"}

{"project":"2_test","denotations":[{"id":"30340614-27799072-30706539","span":{"begin":1023,"end":1024},"obj":"27799072"}],"text":"In principle this can be done by feedback control in which increased concentration somehow modifies the mechanism of elimination to increase the clearance, e.g. by recruiting more transporters. To some extent this occurs with CO2. Increased pCO2 is associated with lower pH and stimulation of cerebral blood flow, which washes away the excess CO2 (see Sect. 5.2), i.e. increased pCO2 increases the clearance for CO2. However, feedback control still requires that there be a change in the concentration to stimulate and maintain the process (see Fig. 24).\nFig. 24 Diagram illustrating possible schemes for neurovascular coupling, i.e. regulation of blood flow changes associated with nerve activity. Two forms of control are shown, a simple feedback based on the signal to be regulated, e.g. pCO2, and b feedback plus feed-forward. The feed-forward element, signal2, in b, possibly from astrocytes, allows blood flow to increase with smaller changes in the primary quantity to be regulated, signal1\n(Figure reproduced from [4])"}