NEUR 3200 Lecture Notes - Lecture 19: Nav1.8, Nmda Receptor, Laboratory Mouse
17 Dec 2017
School
Department
Course
Professor
Document Summary
Scorpion injects venom as a defence mechanism. The toxin induces pain by acting on sodium channels. They still have a functional nav1. 7 channels. Venom inhibits ttx-resistance sodium channel currents in grasshopper mice but - not laboratory mice. Single amino acid residue (e862) near pore region required. Venom reduces ap ring in grasshopper mice but not in lab mice, venom actually increases. Rhythmic oscillations in individual spinal neurons can occur. This is how signalling can occur without signals from the brain. Calcium binds to k channels, causing k to leave the cell. Hyper polarization then occurs (because of the potassium) The calcium then stops owing into the cells. Glutamate causes the cycle to start over again. Cross talk needs to occur via interneurons. Reciprocal inhibition occurs ( exor or extensor is stimulated at one time, can"t be excited both at once) Descending inputs from the brain drive movements. Sensory input is invalid in motor function.
