Last week we took a first look at the structure of neurons and their extended tree-like structures, dendrites and axons. These branching appendages are suitable to establish network connections by contacting other elements of different neurons. In Class One, we also noticed that the fatty double layer of the cellular membrane makes neurons mostly impermeable to polar substances. Tonight we will examine the very core aspects of neuronal transmission, communication, and information processing. This is VERY important material that will be used throughout the rest of the course.
Cations are positive ions, anion are negative ions.
There are also some negatively charged protein molecules. It is important to remember that nerve cells are surrounded by a membrane perforated by proteins that allows some ions to pass through while it blocks the passage of other ions. This type of membrane is called semi-permeable. At rest, the inside of the neuronal membrane is slightly negative relative to the outside. Cellular membrane have highly apolar inner volumes.