NROB60H3 Chapter Notes - Chapter 3: Goldman Equation, Eion, Astrocyte
Document Summary
The axonal membrane has properties that enable it to conduct an action potential (nerve impulse) that overcome biological constraints: potential refers to the separation of electrical charge across the membrane, action potentials do not diminish over distance. Information is encoded in the frequency of action potentials of individual neurons as well as in the distribution and number of neurons firing action potentials in a given nerve. Cells capable of generating and conducting action potentials are said to have excitable membrane. Electrically charged atoms (ions) that are dissolved in water are responsible for the resting and action potentials: the most important property of the water molecule is its uneven distribution of electrical charge. These shared electrons spend more time associated with the oxygen atom than with the two hydrogen atoms. The oxygen atom acquires a net negative charge, and the hydrogen atoms acquire a net positive charge. Water is said to be a polar molecule, held together by polar covalent bonds.
