scholarly journals Type I and Type II Neuron Models Are Selectively Driven by Differential Stimulus Features

2008 ◽  
Vol 20 (10) ◽  
pp. 2418-2440 ◽  
Author(s):  
Germán Mato ◽  
Inés Samengo
Keyword(s):  
Normal Forms ◽  
Type I ◽  
Type Ii ◽  
Neuron Models ◽  
Scale Free ◽  
Differential Stimulus ◽  
Physiological Properties ◽  
Dynamical Properties ◽  
Stimulus Features ◽  
Type Ii Neuron

Neurons in the nervous system exhibit an outstanding variety of morphological and physiological properties. However, close to threshold, this remarkable richness may be grouped succinctly into two basic types of excitability, often referred to as type I and type II. The dynamical traits of these two neuron types have been extensively characterized. It would be interesting, however, to understand the information-processing consequences of their dynamical properties. To that end, here we determine the differences between the stimulus features inducing firing in type I and type II neurons. We work with both realistic conductance-based models and minimal normal forms. We conclude that type I neurons fire in response to scale-free depolarizing stimuli. Type II neurons, instead, are most efficiently driven by input stimuli containing both depolarizing and hyperpolarizing phases, with significant power in the frequency band corresponding to the intrinsic frequencies of the cell.

scholarly journals Scaling law for the transient behavior of type-II neuron models

2007 ◽  
Vol 75 (2) ◽  
Author(s):  
M. A. D. Roa ◽  
M. Copelli ◽  
O. Kinouchi ◽  
N. Caticha
Keyword(s):  
Scaling Law ◽  
Transient Behavior ◽  
Type Ii ◽  
Neuron Models ◽  
Type Ii Neuron

scholarly journals A-current and type I/type II transition determine collective spiking from common input

2012 ◽  
Vol 108 (6) ◽  
pp. 1631-1645 ◽  
Author(s):  
Andrea K. Barreiro ◽  
Evan L. Thilo ◽  
Eric Shea-Brown
Keyword(s):  
Time Scales ◽  
Cell Populations ◽  
Type I ◽  
Time Lags ◽  
Type Ii ◽  
Neuron Models ◽  
Common Input ◽  
Time Constants ◽  
Long Time ◽  
Short Time

The mechanisms and impact of correlated, or synchronous, firing among pairs and groups of neurons are under intense investigation throughout the nervous system. A ubiquitous circuit feature that can give rise to such correlations consists of overlapping, or common, inputs to pairs and populations of cells, leading to common spike train responses. Here, we use computational tools to study how the transfer of common input currents into common spike outputs is modulated by the physiology of the recipient cells. We focus on a key conductance, gA, for the A-type potassium current, which drives neurons between “type II” excitability (low gA), and “type I” excitability (high gA). Regardless of gA, cells transform common input fluctuations into a tendency to spike nearly simultaneously. However, this process is more pronounced at low gA values. Thus, for a given level of common input, type II neurons produce spikes that are relatively more correlated over short time scales. Over long time scales, the trend reverses, with type II neurons producing relatively less correlated spike trains. This is because these cells' increased tendency for simultaneous spiking is balanced by an anticorrelation of spikes at larger time lags. These findings extend and interpret prior findings for phase oscillators to conductance-based neuron models that cover both oscillatory (superthreshold) and subthreshold firing regimes. We demonstrate a novel implication for neural signal processing: downstream cells with long time constants are selectively driven by type I cell populations upstream and those with short time constants by type II cell populations. Our results are established via high-throughput numerical simulations and explained via the cells' filtering properties and nonlinear dynamics.

scholarly journals Categorization of Neural Excitability Using Threshold Models

2005 ◽  
Vol 17 (7) ◽  
pp. 1447-1455 ◽  
Author(s):  
A. Tonnelier
Keyword(s):  
Action Potentials ◽  
Recovery Process ◽  
Type I ◽  
Type Ii ◽  
Neuron Models ◽  
Neural Excitability ◽  
Spiking Neuron Models ◽  
Crucial Characteristic

A classification of spiking neurons according to the transition from quiescence to periodic firing of action potentials is commonly used. Nonbursting neurons are classified into two types, type I and type II excitability. We use simple phenomenological spiking neuron models to derive a criterion for the determination of the neural excitability based on the after potential following a spike. The crucial characteristic is the existence for type II model of a positive overshoot, that is, a delayed after depolarization, during the recovery process of the membrane potential. Our prediction is numerically tested using well-known type I and type II models including the Connor, Walter, & McKown (1977) model and the Hodgkin-Huxley (1952) model.

On Link Density and Network Synchronization in Scale-Free Network

2013 ◽  
Vol 380-384 ◽  
pp. 2276-2279
Author(s):  
Wen Wei Liu ◽  
Dan Wang
Keyword(s):  
Network Size ◽  
Type I ◽  
Type Ii ◽  
Scale Free Network ◽  
Network Synchronization ◽  
Scale Free ◽  
Weighted Networks ◽  
Link Density ◽  
Free Network

The relations between link density and network synchronizability based on scale-free weighted networks is investigated. In this work, it shows that synchronizability of networks Type I decrease along with the increases of link density, when the netwrok size is fixed. While the synchronizability of networks Type II is remarkable decreased by enhancing the link density with different network size.

Physiological Properties of Neurons in the Ventral Nucleus of the Lateral Lemniscus of the Rat: Intrinsic Membrane Properties and Synaptic Responses

1999 ◽  
Vol 81 (6) ◽  
pp. 2862-2874 ◽  
Author(s):  
Shu Hui Wu
Keyword(s):  
Membrane Properties ◽  
Type I ◽  
Type Ii ◽  
Lateral Lemniscus ◽  
Positive Current ◽  
Physiological Properties ◽  
Current Voltage ◽  
Ventral Nucleus ◽  
Intrinsic Membrane Properties ◽  
Synaptic Responses

Physiological properties of neurons in the ventral nucleus of the lateral lemniscus of the rat: intrinsic membrane properties and synaptic responses. The physiological properties including current-voltage relationships, firing patterns, and synaptic responses of the neurons in the ventral nucleus of the lateral lemniscus (VNLL) were studied in brain slices taken through the young rat’s (17–37 days old) auditory brain stem. Intracellular recordings were made from VNLL neurons, and synaptic potentials were elicited by electrical stimulation of the lateral lemniscus ventral to the VNLL. Current-voltage relations and firing patterns were tested by recording the electrical potentials produced by intracellular injection of positive and negative currents. There were two types of VNLL neurons (type I and II) that exhibited different current-voltage relationships. In response to negative current, both type I and II neurons produced a graded hyperpolarization. Type I neurons responded to positive current with a graded depolarization and multiple action potentials the number of which was related to the strength of the current injected. The current-voltage relations of type I neurons were nearly linear. Type II neurons responded to positive current with a limited depolarization and only one or a few action potentials. The current-voltage relations of type II neurons were nonlinear near the resting potential. The membrane properties of the type II VNLL neurons may play an important role for processing information about time of onset of a sound. Type I neurons showed three different firing patterns, i.e., regular, onset-pause and adaptation, in response to small positive current. The onset-pause and adaptation patterns could become sustained when a large current was injected. The regular, onset-pause, and adaptation patterns in type I neurons and the onset pattern in type II neurons resemble “chopper,” “pauser,” “primary-like,” and “on” responses, respectively, as defined in in vivo VNLL studies. The results suggest that different responses to acoustic stimulation could be attributed to intrinsic membrane properties of VNLL neurons. Many VNLL neurons responded to stimulation of the lateral lemniscus with excitatory or inhibitory responses or both. Excitatory and inhibitory responses showed interaction, and the output of the synaptic integration depended on the relative strength of excitatory and inhibitory responses. Neurons with an onset-pause firing pattern were more likely to receive mixed excitatory and inhibitory inputs from the lower auditory brain stem.

Properties of the trochanteral hair plate and its function in the control of walking in the cockroach

1976 ◽  
Vol 64 (1) ◽  
pp. 233-249 ◽  
Author(s):  
R. K. Wong ◽  
K. G. Pearson
Keyword(s):  
Inhibitory Effect ◽  
Short Latency ◽  
Inhibitory Influence ◽  
Type I ◽  
Type Ii ◽  
Step Cycle ◽  
Excitatory Effect ◽  
Physiological Properties ◽  
Hair Sensilla ◽  
Leg Movement

1. The physiological properties of the group of long hair sensilla of the trochanteral hair plate in the cockroach metathoracic leg were studied. The sensilla were divided into type I and type II according to their responses to imposed displacements. 2. Type I hair sensilla responded to dynamic displacements whereas type II hair sensilla responded to both dynamic and static displacements. The hair sensilla are normally excited by phasic flexion movements of the femur near the end of leg protraction. 3. Activity in the trochanteral hair plate afferents had a short latency excitatory effect on the motoneurone producing slow extension movements of the femur and an inhibitory effect on the femur flexor motoneurones. 4. Removal of the trochanteral hair plate in one leg caused overstepping of that leg in a walking animal due to exaggerated flexion of the femur. This change in leg movement can be explained by the removal of the inhibitory influence from the hair plate afferents to the femur flexor motoneurones. 5. We conclude that one function of the trochanteral hair plate is to limit femur flexion during a step cycle.

scholarly journals Moving beyond Type I and Type II neuron types

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 19 ◽  
Author(s):  
Frances K Skinner
Keyword(s):  
Mathematical Models ◽  
Neurological Disease ◽  
Brain Networks ◽  
Cell Types ◽  
The Other ◽  
Type I ◽  
Type Ii ◽  
Network Synchronization ◽  
Biological Context ◽  
Type Ii Neuron

In 1948, Hodgkin delineated different classes of axonal firing.  This has been mathematically translated allowing insight and understanding to emerge.  As such, the terminology of ‘Type I’ and ‘Type II’ neurons is commonplace in the Neuroscience literature today.  Theoretical insights have helped us realize that, for example, network synchronization depends on whether neurons are Type I or Type II.  Mathematical models are precise with analyses (considering Type I/II aspects), but experimentally, the distinction can be less clear.  On the other hand, experiments are becoming more sophisticated in terms of distinguishing and manipulating particular cell types but are limited in terms of being able to consider network aspects simultaneously.   Although there is much work going on mathematically and experimentally, in my opinion it is becoming common that models are either superficially linked with experiment or not described in enough detail to appreciate the biological context.  Overall, we all suffer in terms of impeding our understanding of brain networks and applying our understanding to neurological disease.  I suggest that more modelers become familiar with experimental details and that more experimentalists appreciate modeling assumptions. In other words, we need to move beyond our comfort zones.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

1984 ◽  
Vol 42 ◽  
pp. 250-251
Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson
Keyword(s):  
Endoplasmic Reticulum ◽  
Experimental Infection ◽  
Uranyl Acetate ◽  
Type I ◽  
Cellular Injury ◽  
Type Ii ◽  
Tubular Structures ◽  
Type Iii ◽  
Type Iv ◽  
Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

Comparative surface and ultrastructural views of methylotrophic bacteria by TEM, STEM, SE, and freeze-etch electron microscopy.

1987 ◽  
Vol 45 ◽  
pp. 792-793
Author(s):  
T.A. Fassel ◽  
M.J. Schaller ◽  
M.E. Lidstrom ◽  
C.C. Remsen
Keyword(s):  
Cytoplasmic Membrane ◽  
Structural Features ◽  
Methylotrophic Bacteria ◽  
Type I ◽  
Type Ii ◽  
Membrane Complex ◽  
Oxidation Of Methane ◽  
Methane Oxidizing Bacteria ◽  
Wall Structures ◽  
Methylomonas Albus

Methylotrophic bacteria play an Important role in the environment in the oxidation of methane and methanol. Extensive intracytoplasmic membranes (ICM) have been associated with the oxidation processes in methylotrophs and chemolithotrophic bacteria. Classification on the basis of ICM arrangement distinguishes 2 types of methylotrophs. Bundles or vesicular stacks of ICM located away from the cytoplasmic membrane and extending into the cytoplasm are present in Type I methylotrophs. In Type II methylotrophs, the ICM form pairs of peripheral membranes located parallel to the cytoplasmic membrane. Complex cell wall structures of tightly packed cup-shaped subunits have been described in strains of marine and freshwater phototrophic sulfur bacteria and several strains of methane oxidizing bacteria. We examined the ultrastructure of the methylotrophs with particular view of the ICM and surface structural features, between representatives of the Type I Methylomonas albus (BG8), and Type II Methylosinus trichosporium (OB-36).

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