Trace Potential in Neurophysiology

The trace potential is the slow change in membrane potential that occurs after the end of the action potential. This phenomenon is associated with restoration processes occurring in excitable tissues after excitation.

The trace potential arises as a result of changes in the concentration of sodium and potassium ions in the cytoplasm of the cell. When the action potential reaches its peak, the concentration of sodium ions in the cytoplasm increases sharply, resulting in an increase in the rate of membrane depolarization. However, after the end of the action potential, the concentration of potassium ions in the cytoplasm quickly decreases, which leads to a slowdown in membrane depolarization and the appearance of a trace potential.

Trace potentials can be either positive or negative. A positive trace potential indicates that the cell membrane has become less polarized than it was before excitation. A negative trace potential indicates that the membrane has become more polarized.

In neurophysiology, trace potentials play an important role. They help regulate the excitability of neurons and determine the speed of transmission of nerve impulses. Trace potentials can also be used to study the mechanisms of neuroplasticity and the restoration of neural networks after damage.

Studying trace potentials can help in understanding the mechanisms of the nervous system and developing new methods for treating neurological diseases.

Trace potential is a phenomenon in the electrophysiology of excitable tissues, which manifests itself as a slow (for nerve fibers 0.05-0.1 ms) change in their membrane potential to the final resting potential after a disturbance in the electrical equilibrium between excitable structures. Restoration of the equilibrium potential may not occur immediately, but after some time, i.e., a person may interrupt activity at a certain moment, but not complete it immediately. Rapid oscillatory changes in membrane potential during nerve cell activity can cause the firing of synchronous depolarizing postsynaptic potentials or local hyperpolarization, which can lead to the generation of an action potential by a number of neighboring non-excited cells or by just one neighboring cell. This property underlies the transmission of excitation along nerve fibers from the body of one neuron to the body of another. After the cessation of resting membrane potentials, the summation of local potentials in the membrane occurs due to a decrease in the permeability of potassium ions due to the spread of excitation through synapses and the redistribution of the concentration of intracellular Ca and Na (see potentials) in the synapse terminals. Trace potentials can also be important in memory mechanisms, in the formation of trigger mechanisms (for example, a nerve impulse) and in a number of other processes in the functioning of the nervous system.