PSYC 3030 Chapter Notes - Chapter 4: Astrocyte, Blepharospasm, Striatum
Document Summary
Membrane potential is the difference in electrical charge between the inside and outside of a cell. Must position the tip of one electrode inside the neuron and the tip of another electrode outside the neuron in the extracellular fluid. Intracellular electrode must be thin and precise: microelectrode. If both electrodes are in the ecf: potential= 0mv. If electrode is in the intracellular neuron: potential= -70mv. Salts in neural tissues separate into positive and negative ions. Potential is a result of an imbalance between +ve / -ve ions. This occurs because : random motion: ions in neural tissues are always in constant motion, concentration gradient: particles in random motion tend to become evenly distributed because they move down concentration gradients. (normally). High low: electrostatic pressure: accumulation of charges in one area tends to be dispersed by the repulsion of like charges and attraction of opposite charges. Negatively charged proteins (tends to not leave the inside)
