Neuron communication.
Single neuron recordings
Ephaptic coupling of cortical neurons.
The group of Prof. Henry Markram (LNMC - Neural Microcircuitry Laboratory), together with researchers of California Institute of Technology, Imperial College and the Korea University, stimulated and recorded from rat cortical pyramidal neurons in slices with a 12-electrode setup, to address the question to which extent ephaptic coupling alters the functioning of neurons under physiological conditions. They found that extracellular fields induced ephaptically mediated changes in the somatic membrane potential that were less than 0.5 mV under subthreshold conditions. Despite their small size, these fields could strongly entrain action potentials, particularly for slow (<8 Hz) fluctuations of the extracellular field. Their findings indicate that endogenous brain activity can causally affect neural function through field effects under physiological conditions.