Search results
Results from the WOW.Com Content Network
[58] [77] More specifically, the scalp electrical potentials that produce EEG are generally thought to be caused by the extracellular ionic currents caused by dendritic electrical activity, whereas the fields producing magnetoencephalographic signals [28] are associated with intracellular ionic currents. [78]
For small voltage increases from rest, the potassium current exceeds the sodium current and the voltage returns to its normal resting value, typically −70 mV. [ 7 ] [ 8 ] [ 9 ] However, if the voltage increases past a critical threshold, typically 15 mV higher than the resting value, the sodium current dominates.
In neuroscience, an excitatory postsynaptic potential (EPSP) is a postsynaptic potential that makes the postsynaptic neuron more likely to fire an action potential. This temporary depolarization of postsynaptic membrane potential , caused by the flow of positively charged ions into the postsynaptic cell, is a result of opening ligand-gated ion ...
The current spreads quicker in a cell with less resistance, and is more likely to reach the threshold at other portions of the neuron. [ 3 ] The threshold potential has also been shown experimentally to adapt to slow changes in input characteristics by regulating sodium channel density as well as inactivating these sodium channels overall.
Electrical input–output membrane voltage models – These models produce a prediction for membrane output voltage as a function of electrical stimulation given as current or voltage input. The various models in this category differ in the exact functional relationship between the input current and the output voltage and in the level of detail.
A number of nuclei in the brainstem have diffuse projections throughout the brain influencing concentration levels of neurotransmitters such as norepinephrine, acetylcholine and serotonin. These neurotransmitter systems affect the physiological state, e.g., wakefulness or arousal , and have a pronounced effect on amplitude of different brain ...
An event-related potential (ERP) is the measured brain response that is the direct result of a specific sensory, cognitive, or motor event. [1] More formally, it is any stereotyped electrophysiological response to a stimulus. The study of the brain in this way provides a noninvasive means of evaluating brain functioning.
The higher the axoplasmic resistance, , the smaller the value of , the harder it will be for current to travel through the axoplasm, and the shorter the current will be able to travel. It is possible to solve equation ( 12 ) and arrive at the following equation (which is valid in steady-state conditions, i.e. when time approaches infinity):