Large naturally-produced electric currents and voltage traverse damaged mammalian spinal cord

Abstract

Background: Immediately after damage to the nervous system, a cascade of physical, physiological, and anatomical events lead to the collapse of neuronal function and often death. This progression of injury processes is called "secondary injury." In the spinal cord and brain, this loss in function and anatomy is largely irreversible, except at the earliest stages. We investigated the most ignored and earliest component of secondary injury. Large bioelectric currents immediately enter damaged cells and tissues of guinea pig spinal cords. The driving force behind these currents is the potential difference of adjacent intact cell membranes. For perhaps days, it is the biophysical events caused by trauma that predominate in the early biology of neurotrauma.

A self-referencing biosensor for real-time monitoring of physiological ATP transport in plant systems

“…nitric oxide, indole acetic acid), and biomolecules (e.g. glucose, glutamate and lactate) Porterfield, 2011, 2013;McLamore et al, 2010;McLamore et al, 2010Porterfield, 2007;Shi et al, 2011;Gilliham et al, 2006;Land et al, 1999;Sanchez et al, 2008;Zuberi et al, 2008;Dey and Raj, 2010;Borgens, 1984).…”

Self-referencing optrodes for measuring spatially resolved, real-time metabolic oxygen flux in plant systems

“…, NH 4 ? ), anions (e.g., NO 2 -, NO 3 -, Cl -), biomolecules (e.g., glucose, dopamine, glutamate), and oxygen (Jaffe and Nuccitelli 1974;Borgens 1984;Land et al 1999;Porterfield et al 1998;Chen et al 2005;Gilliham et al 2006;Shabala et al 2006;Porterfield et al 2007;Zuberi et al 2008;McLamore et al 2009McLamore et al , 2010aPorterfield et al 2009). …”

Extracellular Electrical Fields Direct Wound Healing and Regeneration

“…In lamprey, the rapid decrease in current occurs within the first 2 h and then slowly declines, remaining at 4 A/cm 2 for up to the 6 days after injury that it was measured (Borgens et al, 1980). Current density of 20 A/cm 2 remained for up to 6 h after injury in guinea pig spinal cord explants (Zuberi et al, 2008). Assuming saline resistivity of 100 ⍀cm, extracellular EFs of 40 mV/mm and 200 mV/mm would exist around these injured neurons for an extended time.…”

“…Currents around a single transected neuron are shown for clarity in Figure 1F. Current influx peaks at a few hundred microamperes per square centimeter immediately after transection or crush of lamprey and guinea pig spinal cords (Borgens et al, 1980;Zuberi et al, 2008). In lamprey, the rapid decrease in current occurs within the first 2 h and then slowly declines, remaining at 4 A/cm 2 for up to the 6 days after injury that it was measured (Borgens et al, 1980).…”