Cortical Spreading Depolarization (CSD) Recorded from Intact Skin, from Surface of Dura Mater or Cortex: Comparison with Intracortical Recordings in the Neocortex of Adult Rats.

Cortical Spreading Depolarization (CSD) Recorded from Intact Skin, from Surface of Dura Mater or Cortex: Comparison with Intracortical Recordings in the Neocortex of Adult Rats. Neurochem Res. 2019 Feb 01;: Authors: Lehmenkühler A, Richter F Abstract In cerebral cortex of anesthetized rats single waves of spreading depolarization (CSD) were elicited by needle prick. CSD-related changes of DC (direct current) potentials were either recorded from the intact skin or together with concomitant changes of potassium concentration with K+-selective microelectrodes simultaneously at the surface of the dura mater or of the cortex ([K+]s) and in the extracellular space at a cortical depth of 1200 µm. At the intact skin CSD-related DC-shifts had amplitudes of less than 1 mV and had only in a minority of cases the typical CSD-like shape. In the majority these DC-shifts rose and recovered very slowly and were difficult to identify without further indicators. At dura surface CSD-related DC shifts were significantly smaller and rose and recovered slower than intracortically recorded CSD. Concomitant increases in [K+]s were delayed and reached maximal values of about 5 mM from a baseline of 3 mM. They rose and recovered slower than simultaneously recorded intracortical changes in extracellular potassium concentration ([K+]e) that were up to 65 mM. The results suggest that extracellular potassium during CSD is diffusing through the subarachnoid...
Source: Neurochemical Research - Category: Neuroscience Authors: Tags: Neurochem Res Source Type: research