Front Neurosci: inflammatory response can enhance the sensitivity of neurons to temperature

September 27, 2019 / Biovalley BIOON / -- recently, researchers at North Carolina State University found that inflammation can increase the activity intensity of thermal sensitive neurons in mice, increase gene expression and promote the growth of sensory nerves (neurites), but it will not increase the physical sensation of mice This work reveals the role of inflammation induced overexpression of calcium channel genes in pain hypersensitivity Due to a variety of factors, inflammation usually causes pain hypersensitivity: increased expression of pain receptors; changes in neurotransmitter release in the spinal cord; increased excitability of neurons Studies have shown that voltage-gated calcium channels (VGCC) play an important role in all these changes, because the neurotransmitters they release control the communication between neurons (image source: www Pixabay Com) "in inflammatory state, VGCC plays a role in hyperactivity or hyperactivity of sensory neurons." Santosh Mishra, assistant professor of molecular biomedical science at North Carolina State University and lead author of the work, said: "in addition, calcium molecules released and controlled by these channels regulate the growth of nerve processes We want to look more closely at the role of the VGCC of Cav2.2 to see if it increases the growth of peripheral nerve processes in the process of inflammation " In the peripheral nervous system, neurons are regulated to produce specific nociceptive signals For example, TRPV1 and TRPM8 sensory neurons are associated with heat and cold On the other hand, the neurons expressing mrgprd and mrgprb4 are respectively related to the potential damage of low threshold mechanical sensation Mishra's team chose Cav2.2 because of its rich expression in the dorsal root ganglia (DRG) Using in vitro and in vivo inflammatory mouse models, the team explored the relationship between inflammation, Cav2.2 activity and afferent neurite growth They found that inflammation increased the expression of Cav2.2, which in turn increased the afferent neurite growth and activity of thermosensitive neurons, but did not increase the neurite growth of mechanical neurons "There was no increase in the expression of Cav2.2 channels in mechanical neurons, so there was no significant effect on these neurons," Mishra said "What we don't understand is why inflammation doesn't induce up regulation of calcium channels in mechanical sensation like thermal sensation This may be because there are not so many of these neurons expressing Cav2.2 VGCC, but this is what we need to further study " Mishra hopes the work will help scientists learn more about the causes of chronic pain, especially whether changes in peripheral nerve growth caused by inflammation play a role in the transition from acute to chronic pain The work was published in the journal frontiers in neuroscience Information sources: infection amps up security growth, gene expression involved in heat, cold sensitivity original sources: Saumitra pitake et al, infection induced sensor curve growth and pain hypersensitivity requirements the N-type calcium channel Cav2.2, Frontiers in Neuroscience (2019) Doi: 10.3389/fnins.2019.01009