Search results
Results from the WOW.Com Content Network
Action potentials result from the depolarization of the cell membrane (the sarcolemma), which opens voltage-sensitive sodium channels; these become inactivated and the membrane is repolarized through the outward current of potassium ions. The resting potential prior to the action potential is typically −90mV, somewhat more negative than ...
Afterhyperpolarization, or AHP, is the hyperpolarizing phase of a neuron's action potential where the cell's membrane potential falls below the normal resting potential. This is also commonly referred to as an action potential's undershoot phase. AHPs have been segregated into "fast", "medium", and "slow" components that appear to have distinct ...
As an example, the cardiac action potential illustrates how differently shaped action potentials can be generated on membranes with voltage-sensitive calcium channels and different types of sodium/potassium channels. The second type of mathematical model is a simplification of the first type; the goal is not to reproduce the experimental data ...
The Hodgkin–Huxley model, or conductance-based model, is a mathematical model that describes how action potentials in neurons are initiated and propagated. It is a set of nonlinear differential equations that approximates the electrical engineering characteristics of excitable cells such as neurons and muscle cells.
Actual recordings of action potentials are often distorted compared to the schematic view because of variations in electrophysiological techniques used to make the recording. In electrophysiology , the threshold potential is the critical level to which a membrane potential must be depolarized to initiate an action potential .
An example of inhibitory postsynaptic potentials (IPSPs), excitatory postsynaptic potentials (EPSPs), and their summation. GABA receptors are commonly known to downregulate neuronal activity by various means. GABA A can induce hyperpolarization through an influx of Cl – ions. GABA A itself is a chloride ion channel.
Electrotonic potentials represent changes to the neuron's membrane potential that do not lead to the generation of new current by action potentials. [1] However, all action potentials are begun by electrotonic potentials depolarizing the membrane above the threshold potential which converts the electrotonic potential into an action potential. [2]
GABA A receptor activation allows negatively charged chloride ions to move into the neuron, which inhibits the ability of the neuron to produce action potentials. However, for many cell surface receptors, ligand-receptor interactions are not directly linked to the cell's response.