scholarly journals Electrical Coupling Controls Dimensionality and Chaotic Firing of Inferior Olive Neurons

2019 ◽  
Author(s):  
Huu Hoang ◽  
Eric J. Lang ◽  
Yoshito Hirata ◽  
Isao T. Tokuda ◽  
Kazuyuki Aihara ◽  
...  
Keyword(s):  
Inferior Olive ◽  
Electrical Coupling ◽  
Inferior Olive Neurons

scholarly journals Electrical coupling controls dimensionality and chaotic firing of inferior olive neurons

2020 ◽  
Vol 16 (7) ◽  
pp. e1008075
Author(s):  
Huu Hoang ◽  
Eric J. Lang ◽  
Yoshito Hirata ◽  
Isao T. Tokuda ◽  
Kazuyuki Aihara ◽  
...  
Keyword(s):  
Inferior Olive ◽  
Electrical Coupling ◽  
Inferior Olive Neurons

Chaotic Resonance in Coupled Inferior Olive Neurons with the Llinás Approach Neuron Model

2016 ◽  
Vol 28 (11) ◽  
pp. 2505-2532 ◽  
Author(s):  
Sou Nobukawa ◽  
Haruhiko Nishimura
Keyword(s):  
Learning Process ◽  
Neuron Model ◽  
Inferior Olive ◽  
Electrical Coupling ◽  
Signal Strength ◽  
Compartment Model ◽  
Periodic Signal ◽  
Large Neuron ◽  
Inferior Olive Neurons ◽  
Signal Response

It is well known that cerebellar motor control is fine-tuned by the learning process adjusted according to rich error signals from inferior olive (IO) neurons. Schweighofer and colleagues proposed that these signals can be produced by chaotic irregular firing in the IO neuron assembly; such chaotic resonance (CR) was replicated in their computer demonstration of a Hodgkin-Huxley (HH)-type compartment model. In this study, we examined the response of CR to a periodic signal in the IO neuron assembly comprising the Llinás approach IO neuron model. This system involves empirically observed dynamics of the IO membrane potential and is simpler than the HH-type compartment model. We then clarified its dependence on electrical coupling strength, input signal strength, and frequency. Furthermore, we compared the physiological validity for IO neurons such as low firing rate and sustaining subthreshold oscillation between CR and conventional stochastic resonance (SR) and examined the consistency with asynchronous firings indicated by the previous model-based studies in the cerebellar learning process. In addition, the signal response of CR and SR was investigated in a large neuron assembly. As the result, we confirmed that CR was consistent with the above IO neuron’s characteristics, but it was not as easy for SR.

scholarly journals Electrical coupling controls dimensionality and chaotic firing of inferior olive neurons

2019 ◽  
Author(s):  
Huu Hoang ◽  
Eric J. Lang ◽  
Yoshito Hirata ◽  
Isao T. Tokuda ◽  
Kazuyuki Aihara ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Inferior Olive ◽  
Electrical Coupling ◽  
Training Sample ◽  
Firing Frequency ◽  
Effective Coupling ◽  
Neural Learning ◽  
Inferior Olive Neurons ◽  
Coupling Strengths

SUMMARYOne of the main challenges facing online neural learning systems with numerous modifiable parameters (or “degrees-of-freedom”) such as the cerebellum, is how to avoid “overfitting”. We previously proposed that the cerebellum controls the degree-of-freedoms during learning by gradually modulating the electric coupling strength between inferior olive neurons. Here, we develop a modeling technique to estimate effective coupling strengths between inferior olive neurons from in vivo recordings of Purkinje cell complex spike activity in three different coupling conditions. We show that high coupling strengths induce synchronous firing and decrease the dimensionality of inferior olive firing dynamics. In contrast, intermediate coupling strengths induce chaotic firing and increase the dimensionality of firing dynamics. Our results thus support the hypothesis that effective coupling controls the dimensionality of inferior olive firing, which may allow the olivocerebellar system to learn effectively from a small training sample set despite the low firing frequency of inferior olive neurons.

Adaptive coupling of inferior olive neurons in cerebellar learning

2013 ◽  
Vol 47 ◽  
pp. 42-50 ◽  
Author(s):  
Isao T. Tokuda ◽  
Huu Hoang ◽  
Nicolas Schweighofer ◽  
Mitsuo Kawato
Keyword(s):  
Inferior Olive ◽  
Inferior Olive Neurons ◽  
Adaptive Coupling ◽  
Cerebellar Learning

scholarly journals Encoding of Oscillations by Axonal Bursts in Inferior Olive Neurons

Neuron ◽  
2009 ◽  
Vol 62 (3) ◽  
pp. 388-399 ◽  
Author(s):  
Alexandre Mathy ◽  
Sara S.N. Ho ◽  
Jenny T. Davie ◽  
Ian C. Duguid ◽  
Beverley A. Clark ◽  
...  
Keyword(s):  
Inferior Olive ◽  
Inferior Olive Neurons

scholarly journals Low-Amplitude Oscillations in the Inferior Olive: A Model Based on Electrical Coupling of Neurons With Heterogeneous Channel Densities

1997 ◽  
Vol 77 (5) ◽  
pp. 2736-2752 ◽  
Author(s):  
Yair Manor ◽  
John Rinzel ◽  
Idan Segev ◽  
Yosef Yarom
Keyword(s):  
Inferior Olive ◽  
Electrical Coupling ◽  
The Other ◽  
Sustained Oscillation ◽  
Large Coupling ◽  
Model Based ◽  
Subthreshold Oscillations ◽  
Coupling Current ◽  
Low Amplitude ◽  
Inferior Olivary

Manor, Yair, John Rinzel, Idan Segev, and Yosef Yarom. Low-amplitude oscillations in the inferior olive: a model based on electrical coupling of neurons with heterogeneous channel densities. J. Neurophysiol. 77: 2736–2752, 1997. The mechanism underlying subthreshold oscillations in inferior olivary cells is not known. To study this question, we developed a single-compartment, two-variable, Hodgkin-Huxley-like model for inferior olive neurons. The model consists of a leakage current and a low-threshold calcium current, whose kinetics were experimentally measured in slices. Depending on the maximal calcium and leak conductances, we found that a neuron model's response to current injection could be of four qualitatively different types: always stable, spontaneously oscillating, oscillating with injection of current, and bistable with injection of current. By the use of phase plane techniques, numerical integration, and bifurcation analysis, we subdivided the two-parameter space of channel densities into four regions corresponding to these behavioral types. We further developed, with the use of such techniques, an empirical rule of thumb that characterizes whether two cells when coupled electrically can generate sustained, synchronized oscillations like those observed in inferior olivary cells in slices, of low amplitude (0.1–10 mV) in the frequency range 4–10 Hz. We found that it is not necessary for either cell to be a spontaneous oscillator to obtain a sustained oscillation. On the other hand, two spontaneous oscillators always form an oscillating network when electrically coupled with any arbitrary coupling conductance. In the case of an oscillating pair of electrically coupled nonidentical cells, the coupling current varies periodically and is nonzero even for very large coupling values. The coupling current acts as an equalizing current to reconcile the differences between the two cells' ionic currents. It transiently depolarizes one cell and/or hyperpolarizes the other cell to obtain the regenerative response(s) required for the synchronized oscillation. We suggest that the subthreshold oscillations observed in the inferior olive can emerge from the electrical coupling between neurons with different channel densities, even if the inferior olive nucleus contains no or just a small proportion of spontaneously oscillating neurons.

scholarly journals Electrophysiological Properties of Inferior Olive Neurons: A Compartmental Model

1999 ◽  
Vol 82 (2) ◽  
pp. 804-817 ◽  
Author(s):  
Nicolas Schweighofer ◽  
Kenji Doya ◽  
Mitsuo Kawato
Keyword(s):  
Calcium Current ◽  
Potassium Current ◽  
Inferior Olive ◽  
Sodium Current ◽  
Electrical Coupling ◽  
Biophysical Model ◽  
Delayed Rectifier ◽  
High Threshold ◽  
Electrophysiological Properties

As a step in exploring the functions of the inferior olive, we constructed a biophysical model of the olivary neurons to examine their unique electrophysiological properties. The model consists of two compartments to represent the known distribution of ionic currents across the cell membrane, as well as the dendritic location of the gap junctions and synaptic inputs. The somatic compartment includes a low-threshold calcium current ( I Ca_l), an anomalous inward rectifier current ( I h), a sodium current ( I Na), and a delayed rectifier potassium current ( I K_dr). The dendritic compartment contains a high-threshold calcium current ( I Ca_h), a calcium-dependent potassium current ( I K_Ca), and a current flowing into other cells through electrical coupling ( I c). First, kinetic parameters for these currents were set according to previously reported experimental data. Next, the remaining free parameters were determined to account for both static and spiking properties of single olivary neurons in vitro. We then performed a series of simulated pharmacological experiments using bifurcation analysis and extensive two-parameter searches. Consistent with previous studies, we quantitatively demonstrated the major role of I Ca_l in spiking excitability. In addition, I h had an important modulatory role in the spike generation and period of oscillations, as previously suggested by Bal and McCormick. Finally, we investigated the role of electrical coupling in two coupled spiking cells. Depending on the coupling strength, the hyperpolarization level, and the I Ca_l and I hmodulation, the coupled cells had four different synchronization modes: the cells could be in-phase, phase-shifted, or anti-phase or could exhibit a complex desynchronized spiking mode. Hence these simulation results support the counterintuitive hypothesis that electrical coupling can desynchronize coupled inferior olive cells.

Bifurcation of orbits and synchrony in inferior olive neurons

2011 ◽  
Vol 65 (3) ◽  
pp. 465-491 ◽  
Author(s):  
Keum W. Lee ◽  
Sahjendra N. Singh
Keyword(s):  
Inferior Olive ◽  
Inferior Olive Neurons

Spatial distribution of axon collaterals of single inferior olive neurons

1987 ◽  
Vol 256 (3) ◽  
pp. 317-328 ◽  
Author(s):  
A. Rosina ◽  
L. Provini
Keyword(s):  
Spatial Distribution ◽  
Inferior Olive ◽  
Axon Collaterals ◽  
Inferior Olive Neurons

Epha4 controls the midline crossing and contralateral axonal projections of inferior olive neurons

2012 ◽  
Vol 520 (8) ◽  
pp. 1702-1720 ◽  
Author(s):  
Mitsuhiro Hashimoto ◽  
Rie Ito ◽  
Naohito Kitamura ◽  
Kazunori Namba ◽  
Yasuko Hisano
Keyword(s):  
Inferior Olive ◽  
Axonal Projections ◽  
Midline Crossing ◽  
Inferior Olive Neurons
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