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Action Potentials definition: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
action potential definition: a rapid self-propagating change in the electrical potential across a neuron, gland, or muscle fiber membrane primarily due to a sudden influx of sodium ions followed by an efflux of potassium ions.
Cochlear Microphonic Potentials definition: The electric response of the cochlear hair cells to acoustic stimulation.
cochlear microphonic potential definition: electrical potentials generated in the hair cells of the organ of Corti in response to acoustic stimulation.
Evoked Potentials definition: The recorded electrical responses from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported. Often used synonymously to event-related potentials which are associated with higher level cognitive processes.
evoked potential definition: immediate nervous system electrical response to sensory input; may result from natural, electrical, or chemical stimulation of sensory or motor neurons; used to study neurophysiological phenomena or in clinical diagnosis.
Evoked Potentials, Auditory definition: The electric response evoked in the CEREBRAL CORTEX by ACOUSTIC STIMULATION or stimulation of the AUDITORY PATHWAYS.
Evoked Potentials, Somatosensory definition: The electric response evoked in the CEREBRAL CORTEX by stimulation along AFFERENT PATHWAYS from PERIPHERAL NERVES to CEREBRUM.
Evoked Potentials, Visual definition: The electric response evoked in the cerebral cortex by visual stimulation or stimulation of the visual pathways.
Membrane Potentials definition: The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
membrane potential definition: electrical potential difference across a biological, i.e., cell or organelle, or artificial membrane.
Evoked Potentials, Auditory, Brain Stem definition: Electrical waves in the CEREBRAL CORTEX generated by BRAIN STEM structures in response to auditory click stimuli. These are found to be abnormal in many patients with CEREBELLOPONTINE ANGLE lesions, MULTIPLE SCLEROSIS, or other DEMYELINATING DISEASES.
Synaptic Potentials definition: The voltages across pre- or post-SYNAPTIC MEMBRANES.
Event-Related Potentials, P300 definition: A late-appearing component of the event-related potential. P300 stands for a positive deflection in the event-related voltage potential at 300 millisecond poststimulus. Its amplitude increases with unpredictable, unlikely, or highly significant stimuli and thereby constitutes an index of mental activity. (From Campbell, Psychiatric Dictionary, 6th ed)
Evoked Potentials, Motor definition: The electrical response evoked in a muscle or motor nerve by electrical or magnetic stimulation. Common methods of stimulation are by transcranial electrical and TRANSCRANIAL MAGNETIC STIMULATION. It is often used for monitoring during neurosurgery.
Excitatory Postsynaptic Potentials definition: Depolarization of membrane potentials at the SYNAPTIC MEMBRANES of target neurons during neurotransmission. Excitatory postsynaptic potentials can singly or in summation reach the trigger threshold for ACTION POTENTIALS.
resting potential definition: voltage across a biomembrane in its normal, unstimulated state, typically in the -50 to -100 mV range.
Membrane Potential, Mitochondrial definition: The voltage difference, normally maintained at approximately -180mV, across the INNER MITOCHONDRIAL MEMBRANE, by a net movement of positive charge across the membrane. It is a major component of the PROTON MOTIVE FORCE in MITOCHONDRIA used to drive the synthesis of ATP.
Inhibitory Postsynaptic Potentials definition: Hyperpolarization of membrane potentials at the SYNAPTIC MEMBRANES of target neurons during NEUROTRANSMISSION. They are local changes which diminish responsiveness to excitatory signals.
Postsynaptic Potentials definition: The membrane potentials across the SYNAPTIC MEMBRANES of the target cells of the NEUROTRANSMISSION pathway.
Miniature Postsynaptic Potentials definition: Postsynaptic potentials generated from a release of neurotransmitters from a presynaptic nerve terminal in the absence of an ACTION POTENTIAL. They may be m.e.p.p.s (miniature EXCITATORY POSTSYNAPTIC POTENTIALS) or m.i.p.p.s (miniature INHIBITORY POSTSYNAPTIC POTENTIALS).
Miniature End Plate Potentials definition: A subthreshold depolarizing postsynaptic potential generated at the NEUROMUSCULAR JUNCTION from a spontaneous release of neurotransmitters.
End Plate Potentials definition: Excitatory postsynaptic potentials at the NEUROMUSCULAR JUNCTION.