ABSTRACT
In this chapter, we briey introduce a number of important aspects of neural biophysics necessary to understand the origin of extracellular signals (in particular, voltage deections with respect to a reference electrode far away) in the brain and how these relate to neural function. To do so, we introduce one-dimensional cable theory as well as the most basic mechanisms of action potential (also referred to as a spike) generation (the Hodgkin−Huxley model) and discuss how the currents generated from such processes give rise to extracellular signals. Then, we proceed to present a select few detailed biophysical studies that attempt to tease apart the origin and functionality of extracellular signals induced by action potentials. It is important to understand that this chapter only presents very basic aspects of the biophysics related to intracellular, transmembrane and extracellular features of spikes while omitting fundamental mechanisms of neural function such as synaptic processes. Nevertheless, we hope this chapter will motivate the interested reader to delve deeper into the cosmos of neural biophysics.
