Biological complexity: automatic neuron controls (Introduction)

by David Turell , Thursday, September 22, 2016, 14:54 (2766 days ago) @ David Turell

This study of spinal neurons shows how hey maintain local control of pH levels, while overall body control is mainly through lung gas exchange changes and whart the kidney chooses to keep or remove:-http://www.agnosticweb.com/index.php?mode=posting&id=22898&back=entry-"Bodies like to keep their pH close to 7.4, whether that means hyperventilating to make the blood alkaline, or burning energy, shifting to anaerobic metabolism, and producing lactate to make the blood acidic. The lungs and kidneys can regulate pH changes systemically, but they may not act quickly on a local scale. Because even small pH changes can dramatically affect the nervous system, a study led by Sten Grillner of Karolinska Institute in Sweden looked for a mechanism for pH homeostasis in the spinal cord.-
"Using the lamprey as a model system, the researchers observed that a type of spinal canal neuron, called CSF-c, fired more rapidly when they bathed it with high pH (7.7) or low pH (7.1) media. They could suspend the elevated activity by blocking two ion channels: PKD2L1 channels, which stimulate neurons in alkaline conditions, or ASIC3 channels, which, the team showed previously, do the same in acidic states.-"As the neurons fired, they released the hormone somatostatin, which inhibited the lamprey's locomotor network. These results suggest that, whichever direction pH deviates, “the response of the system is just to reduce activity as much as possible,” Grillner says. The pH-regulating role of CSF-c neurons is likely conserved among animals, the authors suspect, given the presence of these neurons across vertebrate taxa.-“'It's an interesting finding because it adds a level of regulation to maintain homeostasis in the central nervous system,” says Pierre Magistretti of King Abdullah University of Science and Technology in Saudi Arabia who was not involved in the work."-
Comment: Another example of the extreme complexity in the biochemistry of living organisms. Human pH is also kept at 7.4. I would assume the same neurons are in our bodies.