Question

How would do the following question given the intracellular and extracellular recordings of voltage? Calculate the length constant for this axon using the equation for passive electronic decay of a signal: Vx=Vo e^-x/lambda , where x=1 node.

Answer 1

Intracellular recording is an electrophysiology technique that uses a microelectrode inserted into a single cell, usually a neuron, to measure its electrical activity.

Extracellular recording is an electrophysiology technique that uses an electrode inserted into living tissue to measure electrical activity coming from adjacent cells, usually neurons.

The length constant (λ) is a mathematical constant used to quantify the distance that a graded electric potential will travel along a neurite via passive electrical conduction. The greater the value of the length constant, the farther the potential will travel

The length constant of the axon, using the equation for passive electronic decay of signal,

Vx=Vo e^-x/lambda , where x=1 node

Where voltage, V, is measured in millivolts, x is distance from the start of the potential (in millimeters), and λ is the length constant (in millimeters)

when x-1 node

length constant  λ will be (Vo e^- Vx)