Biomaterial Database

Properties of subthreshold response and action potential recorded in layer V neurons from cat sensorimotor cortex in vitro. 1984

C E Stafstrom, and P C Schwindt, and J A Flatman, and W E Crill

Properties of the action potential and subthreshold response were studied in large layer V neurons in in vitro slices of cat sensorimotor cortex using intracellular recording and stimulation, application of agents that block active conductances, and a single-microelectrode voltage clamp (SEVC). A variety of measured parameters, including action-potential duration, afterpotentials, input resistance, rheobase, and membrane time constant, were similar to the same parameters reported for large neurons from this region of cortex in vivo. Action-potential amplitudes and resting potentials were greater in vitro. Most measured parameters were distributed unimodally, suggesting that these parameters are similar in all large layer V neurons irrespective of their axonal termination. The voltage response to subthreshold constant-current pulses exhibited both time and voltage dependence in the great majority of cells. Current pulses in either the hyperpolarizing or subthreshold depolarizing direction cause the membrane potential to attain an early peak and then decay (sag) to a steady level. On termination of the pulse, the membrane response transiently overshoots resting potential. Plots of current-voltage relations demonstrate inward rectification during polarization on either side of resting potential. Subthreshold inward rectification in the depolarizing direction is abolished by tetrodotoxin (TTX). The ionic currents responsible for subthreshold rectification and sag were examined using the SEVC. Steady inward rectification in the depolarizing direction is caused by a persistent, subthreshold sodium current (INaP) (54). Sag observed in response to a depolarizing current pulse is due to activation of a slow outward current, which superimposes on and partially counters the persistent sodium current. Both sag in response to hyperpolarizing current pulses and rectification in the hyperpolarizing direction are caused by a slow inward "sag current" that is activated by hyperpolarizing voltage steps. The sag current is unaltered by TTX, tetraethylammonium, (TEA), Co2+, Ba2+, or 4-aminopyridine. Fast-rising, short-duration action potentials can be elicited by an intracellular current pulse or by orthodromic or antidromic stimulation. Spikes are blocked by TTX. The form of the afterpotential following a directly evoked spike varies among cells with similar resting potentials. Biphasic afterhyperpolarizations (AHPs) with fast and slow components were most frequently seen. About 30% of the cells displayed a depolarizing afterpotential (DAP), which was often followed by an AHP. Other cells displayed a purely monophasic AHP.(ABSTRACT TRUNCATED AT 400 WORDS)

UI	MeSH Term	Description	Entries
D007473	Ion Channels	Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.	Membrane Channels,Ion Channel,Ionic Channel,Ionic Channels,Membrane Channel,Channel, Ion,Channel, Ionic,Channel, Membrane,Channels, Ion,Channels, Ionic,Channels, Membrane
D008297	Male		Males
D009044	Motor Cortex	Area of the FRONTAL LOBE concerned with primary motor control located in the dorsal PRECENTRAL GYRUS immediately anterior to the central sulcus. It is comprised of three areas: the primary motor cortex located on the anterior paracentral lobule on the medial surface of the brain; the premotor cortex located anterior to the primary motor cortex; and the supplementary motor area located on the midline surface of the hemisphere anterior to the primary motor cortex.	Brodmann Area 4,Brodmann Area 6,Brodmann's Area 4,Brodmann's Area 6,Premotor Cortex and Supplementary Motor Cortex,Premotor and Supplementary Motor Cortices,Anterior Central Gyrus,Gyrus Precentralis,Motor Area,Motor Strip,Precentral Gyrus,Precentral Motor Area,Precentral Motor Cortex,Premotor Area,Premotor Cortex,Primary Motor Area,Primary Motor Cortex,Secondary Motor Areas,Secondary Motor Cortex,Somatic Motor Areas,Somatomotor Areas,Supplementary Motor Area,Area 4, Brodmann,Area 4, Brodmann's,Area 6, Brodmann,Area 6, Brodmann's,Area, Motor,Area, Precentral Motor,Area, Premotor,Area, Primary Motor,Area, Secondary Motor,Area, Somatic Motor,Area, Somatomotor,Area, Supplementary Motor,Brodmann's Area 6s,Brodmanns Area 4,Brodmanns Area 6,Central Gyrus, Anterior,Cortex, Motor,Cortex, Precentral Motor,Cortex, Premotor,Cortex, Primary Motor,Cortex, Secondary Motor,Cortices, Secondary Motor,Gyrus, Anterior Central,Gyrus, Precentral,Motor Area, Precentral,Motor Area, Primary,Motor Area, Secondary,Motor Area, Somatic,Motor Areas,Motor Cortex, Precentral,Motor Cortex, Primary,Motor Cortex, Secondary,Motor Strips,Precentral Motor Areas,Precentral Motor Cortices,Premotor Areas,Primary Motor Areas,Primary Motor Cortices,Secondary Motor Area,Secondary Motor Cortices,Somatic Motor Area,Somatomotor Area,Supplementary Motor Areas
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D004553	Electric Conductivity	The ability of a substrate to allow the passage of ELECTRONS.	Electrical Conductivity,Conductivity, Electric,Conductivity, Electrical
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D005071	Evoked Potentials	Electrical responses recorded 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.	Event Related Potential,Event-Related Potentials,Evoked Potential,N100 Evoked Potential,P50 Evoked Potential,N1 Wave,N100 Evoked Potentials,N2 Wave,N200 Evoked Potentials,N3 Wave,N300 Evoked Potentials,N4 Wave,N400 Evoked Potentials,P2 Wave,P200 Evoked Potentials,P50 Evoked Potentials,P50 Wave,P600 Evoked Potentials,Potentials, Event-Related,Event Related Potentials,Event-Related Potential,Evoked Potential, N100,Evoked Potential, N200,Evoked Potential, N300,Evoked Potential, N400,Evoked Potential, P200,Evoked Potential, P50,Evoked Potential, P600,Evoked Potentials, N100,Evoked Potentials, N200,Evoked Potentials, N300,Evoked Potentials, N400,Evoked Potentials, P200,Evoked Potentials, P50,Evoked Potentials, P600,N1 Waves,N2 Waves,N200 Evoked Potential,N3 Waves,N300 Evoked Potential,N4 Waves,N400 Evoked Potential,P2 Waves,P200 Evoked Potential,P50 Waves,P600 Evoked Potential,Potential, Event Related,Potential, Event-Related,Potential, Evoked,Potentials, Event Related,Potentials, Evoked,Potentials, N400 Evoked,Related Potential, Event,Related Potentials, Event,Wave, N1,Wave, N2,Wave, N3,Wave, N4,Wave, P2,Wave, P50,Waves, N1,Waves, N2,Waves, N3,Waves, N4,Waves, P2,Waves, P50
D005260	Female		Females
D000222	Adaptation, Physiological	The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.	Adaptation, Physiologic,Adaptations, Physiologic,Adaptations, Physiological,Adaptive Plasticity,Phenotypic Plasticity,Physiological Adaptation,Physiologic Adaptation,Physiologic Adaptations,Physiological Adaptations,Plasticity, Adaptive,Plasticity, Phenotypic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia