Shigeru Tanaka

Shigeru Tanaka
Numazu National College of Technology

PhD

About

140
Publications
7,886
Reads
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1,905
Citations
Additional affiliations
May 2013 - December 2021
The University of Electro-Communications
Position
  • Professor
October 1994 - September 2021
RIKEN
Position
  • Laboratory Manager
Description
  • A laboratory head of Visual Neurocomputing. Research on the postnatal development of visual cortex of young mammals (cats, rats and mice) depending on visual experience from both animal experiment and mathematical modeling aspects.
Education
April 1981 - March 1986
The University of Tokyo
Field of study
  • Physics

Publications

Publications (140)
Article
In an early stage of the postnatal development of cats, orientation maps mature and spatial frequency selectivity is consolidated. To investigate the time course of orientation map maturation associated with the consolidation of spatial frequency selectivity, we performed optical imaging of intrinsic signals in areas 17 and 18 of cats under the sti...
Article
Recently, intrinsic signal optical imaging has been widely used as a routine procedure for visualizing cortical functional maps. We do not, however, have a well-established imaging method for visualizing cortical functional connectivity indicating spatio-temporal patterns of activity propagation in the cerebral cortex. In the present study, we deve...
Article
Full-text available
A long-standing question in neuroscience is how the brain controls movement that requires precisely timed muscle activations. Studies using Pavlovian delay eyeblink conditioning provide good insight into this question. In delay eyeblink conditioning, which is believed to involve the cerebellum, a subject learns an interstimulus interval (ISI) betwe...
Article
Full-text available
To date, numerous mathematical models have been proposed on the basis of some types of Hebbian synaptic learning to account for the activity-dependent development of orientation maps as well as neuronal orientation selectivity. These models successfully reproduced orientation map-like spatial patterns. Nevertheless, we still have questions: (1) How...
Article
Full-text available
Altered sensory experience in early life often leads to remarkable adaptations so that humans and animals can make the best use of the available information in a particular environment. By restricting visual input to a limited range of orientations in young animals, this investigation shows that stimulus selectivity, e.g., the sharpness of tuning o...
Article
Full-text available
Long-term depression (LTD) at parallel fiber-Purkinje cell (PF-PC) synapses is thought to underlie memory formation in cerebellar motor learning. Recent experimental results, however, suggest that multiple plasticity mechanisms in the cerebellar cortex and cerebellar/vestibular nuclei participate in memory formation. To examine this possibility, we...
Article
Full-text available
Finding the rules underlying how axons of cortical neurons form neural circuits and modify their corresponding synaptic strength is the still subject of intense research. Experiments have shown that internal calcium concentration, and both the precise timing and temporal order of pre and postsynaptic action potentials, are important constituents go...
Article
Full-text available
Ocular dominance columns (ODCs) have been well studied in the striate cortex (V1) of macaques, as well defined arrays of columnar structure that receive inputs from one eye or the other, whereas ODC expression seems more obscure in some New World primate species. ODCs have been identified by means of eye injections of transneuronal transporters and...
Chapter
In the present model, in which the cortical interaction function is isotropic, clustering of similar visual features occurs but columnar organization cannot be formed even in flat parts of the model visual cortex when the simulation is carried out to update features sampled randomly from the entire model cortex. So, we carried out the simulation ac...
Article
Full-text available
It has been widely accepted that ocular dominance in the responses of visual cortical neurons can change depending on visual experience in a postnatal period. However, experience-dependent plasticity for orientation selectivity, which is another important response property of visual cortical neurons, is not yet fully understood. To address this iss...
Data
Full-text available
It has been widely accepted that ocular dominance in the responses of visual cortical neurons can change depending on visual experience in a postnatal period. However, experience-dependent plasticity for orientation selectivity, which is another important response property of visual cortical neurons, is not yet fully understood. To address this iss...
Article
Full-text available
Kaschube et al. (Reports, 19 November 2010, p. 1113) argue that pinwheel density in three mammalian species follows a universal constant of π as predicted by their orientation-selective suppressive long-range connectivity model. We dispute their conclusions and suggest that a simple brain size-pinwheel density scaling law suffices in predicting the...
Data
Oscillation index (OI) and POT-representation index (PI) for the injection of a small current (IMF-grc = 10.7 pA in A) and a large current (IMF-grc = 22.7 pA in B) while varying the ratio in strength of the current injected to Gocs to that injected to grcs. A, In the case of a small current injection to grcs, as the ratio increased, OI sharply decr...
Data
Normalized autocorrelation functions (A, B, E, F, I and J) and similarity indices (C, D, G, H, K and L) of Goc spike activities at default, high, and low values of [Mg2+] (from top to bottom), respectively. The left column (A, C, E, G, I and K) was calculated from Goc spike activities when a small current was injected to the grcs, whereas the right...
Data
Network behaviors in the parameter space spanned by [Mg2+] and IMF. The oscillation index (A) and POT-representation index (B), which characterize the network dynamics, are plotted in the parameter space with different colors. Figure 8 was obtained by overlapping A and B. (TIFF)
Data
Tabular description of the present network model. (DOC)
Article
Full-text available
Information processing of the cerebellar granular layer composed of granule and Golgi cells is regarded as an important first step toward the cerebellar computation. Our previous theoretical studies have shown that granule cells can exhibit random alternation between burst and silent modes, which provides a basis of population representation of the...
Article
In the cat primary visual cortex, it is accepted that neurons optimally responding to similar stimulus orientations are clustered in a column extending from the superficial to deep layers. The cerebral cortex is, however, folded inside a skull, which makes gyri and fundi. The primary visual area of cats, area 17, is located on the fold of the corte...
Article
Full-text available
Synapse location, dendritic active properties and synaptic plasticity are all known to play some role in shaping the different input streams impinging onto a neuron. It remains unclear however, how the magnitude and spatial distribution of synaptic efficacies emerge from this interplay. Here, we investigate this interplay using a biophysically deta...
Conference Paper
We have developed a network model of cerebellar cortex, in which granular cells’ activities represent a passage of time from the onset of a conditioned stimulus (CS). Long-term depression of parallel fiber synapses at Purkinje cells (PCs) encodes an interstimulus interval between onsets of a CS and an unconditioned stimulus (US) as cessation of PC...
Article
To date, Hebbian learning combined with some form of constraint on synaptic inputs has been demonstrated to describe well the development of neural networks. The previous models revealed mathematically the importance of synaptic constraints to reproduce orientation selectivity in the visual cortical neurons, but biological mechanisms underlying suc...
Data
Sample-averaged orientation histograms of normal kittens. (a, b): Orientation histograms obtained by averaging 10 normal kittens (P26–32), and 15 normal kittens (P45–84), respectively. *: p<0.05; **: p<0.005; ***: p<0.001 (post hoc analysis by Tukey's HSD test). In this analysis, we used data obtained from repeated optical imaging on 9 animals of t...
Data
Effects of D-AP5 infusion in single-orientation maps. Single-orientation maps of a kitten, in which 1-week GR and concurrent D-AP5 infusion were started at P24 and P30, respectively. Corresponding cortical domains in the right control hemisphere are delineated by blue lines and those in the left D-AP5-treated hemisphere are delineated by red lines....
Data
Orientation histogram obtained from single-unit recordings along the tracks when electrodes were penetrated into the medial bank of 3 cats exposed to vertical orientation. By courtesy of Dr. Ohzawa. (2.06 MB TIF)
Data
Time course of the normalized relative area of the exposed orientation in kittens exposed to a stationary stripe pattern. Blue: horizontally oriented stripe of 0.15 cpd; Red: vertically oriented strip of 0.15 cpd; Sky blue: horizontally oriented stripe of 0.5 cpd; Pink: vertically oriented stripe of 0.5 cpd. The origin in the day of GR indicates th...
Article
Full-text available
Orientation selectivity of primary visual cortical neurons is an important requisite for shape perception. Although numerous studies have been previously devoted to a question of how orientation selectivity is established and elaborated in early life, how the susceptibility of orientation plasticity to visual experience changes in time remains uncl...
Article
Abstract  In the present study, we first attempt to construct a model for the dynamics of city images, in which intra- and intercity communications promote the joint possession of city images by residents and the establishment of a city identity. It is suggested that community spirit, which emerges strongly associated with city identity, urges citi...
Article
Experimentally induced changes in the central visual pathway were studied by using positron emission tomography in monkeys with unilateral hypertension glaucoma. In 2-[18F]fluoro-2-deoxy-glucose studies, monocular visual stimulation of the affected eye yielded significantly reduced neural responses in the occipital visuocortical areas. The response...
Article
To examine whether orientation selectivity in the mouse visual cortex can change depending on visual experience, we reared juvenile and adult mice under single-orientation exposure using cylindrical-lens-fitted goggles that extremely elongate visual images vertically. Immediately after goggle rearing, we performed optical imaging of intrinsic signa...
Article
Full-text available
Reservoir computing (RC) is a new framework for neural computation. A reservoir is usually a recurrent neural network with fixed random connections. In this article, we propose an RC model in which the connections in the reservoir are modifiable. Specifically, we consider correlation-based learning (CBL), which modifies the connection weight betwee...
Article
Higher visual cortical areas are involved in the perception of complex stimuli, such as the optic flow created by self-motion. On the other hand, area 18 is thought to extract primitive visual features, feeding higher cortical areas for further processing. In this study, we applied optical imaging of intrinsic signals in the central, lower visual f...
Article
We carried out voltage-sensitive dye imaging of the guinea pig auditory cortex to determine whether the ongoing and spontaneous activities of the cortex exhibit spatial coherence reflecting the tonotopic organization of the cortex. We used independent component analysis and a signal-plus-noise model to extract ongoing activities from the observed s...
Data
We carried out voltage-sensitive dye imaging of the guinea pig auditory cortex to determine whether the ongoing and spontaneous activities of the cortex exhibit spatial coherence reflecting the tonotopic organization of the cortex.We used independent component analysis and a signal-plusnoise model to extract ongoing activities from the observed sig...
Article
In Pavlovian delay eyeblink conditioning, the cerebellum represents the passage-of-time (POT) between onsets of conditioned and unconditioned stimuli (CS and US, respectively). To study possible computational mechanisms of the POT representation we built a large-scale spiking network model of the cerebellum. Consistent with our previous rate-coding...
Article
We examined activity fluctuations as ongoing and spontaneous activities that were recorded with voltage sensitive dye imaging in the auditory cortex of guinea pigs. We investigated whether such activities demonstrated spatial coherence, which represents the cortical functional organization. We used independent component analysis to extract neural a...
Article
Full-text available
In order to gain a better theoretical understanding of the interaction between voltage and calcium influx, we present the simulation results for saltatory transmission in a sparsely excitable model of a continuous cylindrical segment of nerve fiber, where calcium diffuses internally and various ion channels are distributed as hotspots along the cab...
Article
Adult cats lack ocular dominance plasticity, showing little change in the ocular dominance distribution following monocular deprivation. Ocular dominance plasticity is also lost in kitten visual cortex that has been continuously infused with either catecholaminergic neurotoxin, beta-adrenoreceptor blocker, or inhibitor of cyclic AMP-dependent prote...
Article
We used the intrinsic signal optical imaging technique to assess the effect of orientation-restricted visual experience on response properties of the rat visual cortex. We placed young animals wearing goggles fitted with plano-convex cylindrical lenses in a stimulus-enriched environment for 3 weeks. Experienced orientation was over-represented in t...
Article
We examined closely the cerebellar circuit model that we have proposed previously. The model granular layer generates a finite but very long sequence of active neuron populations without recurrence, which is able to represent the passage of time. For all the possible binary patterns fed into mossy fibres, the circuit generates the same number of di...
Article
To examine the effect of experience on the developmental plasticity of functional maps in the visual cortex, we need to establish a method for a stable visual experience manipulation under the freely moving condition. For this purpose, we fabricated goggles that are chronically mounted stably on the animal's head, but easy to replace according to t...
Article
Full-text available
In the study of the spatiotemporal properties of the cortex, a demand often arises for recording local field evoked potentials (LFEP) and neural spikes from a quantity of points at close range from each other. In such a situation a device composed of a lot of electrodes assembled in a single bunch would be suitable. Such circumstances gave us the i...
Article
In the visual cortex, pinwheel centers, which appear as point singularities in orientation maps, are likely to be found at the centers of ocular dominance columns in normal cats and monkeys. To elucidate the mechanism underlying the geometrical relationship, we performed computer simulation based on our correlation-based self-organization model. Th...
Article
Full-text available
In the rat barrel cortex, neurons in layer 4 are topographically arranged in a precise columnar structure, and the excitatory feed-forward input from layer 4 to layer 2/3 projects almost exclusively within the home barrel column. Here we analyzed the lateral connectivity that links neighboring columns in layer 2/3, which is necessary for integratin...
Article
The role of spike-timing-dependent plasticity (STDP) in shaping the strength of a synapse located on the dendritic tree has gained recent interest. Previous theoretical studies using STDP have mostly used simplified integrate-and-fire models to investigate the evolution of synaptic efficacy with time. Such studies usually show that the final weight...
Article
Full-text available
The interaction between membrane potential and internal calcium concentration plays many important roles in regulating synaptic integration and neuronal firing. In order to gain a better theoretical understanding between the voltage-calcium interaction, a nonlinear cable equation with calcium dynamics is solved analytically. This general reaction-d...
Article
The intrinsic optical imaging technique has been widely applied for the visualization of functional maps in the sensory cortices of mammals. Many current studies refer this mapping in order to focus thereafter on particular features, at some particular locations: a fast and accurate mapping is therefore required. However, even during a successful e...
Article
We investigated how neural function is preserved or matured in the visual cortex of cats, following the induction of hydrocephalus by kaolin injection. In vivo optical imaging of intrinsic signals in 11-17-week-old hydrocephalic cats revealed orientation maps showing the orderly arrangement of preferred orientations when stimulated by grating stimu...
Article
To elucidate the effect of visual experience on the development of orientation maps, we conducted intrinsic signal optical imaging of the visual cortex of kittens that were continuously exposed to a single orientation through cylindrical-lens-fitted goggles under a freely moving condition starting at post-natal week 3. We observed a rapid reorganiz...
Conference Paper
We have built a realistic computational model of the cerebellum. This model simulates the cerebellar cortex of the size 0.5mm × 1mm consisting of several types of neurons, which are modeled as conductancebased leaky integrate-and-.re units with realistic values of parameters adopted from known anatomical and physiological data. We demonstrate that...
Article
Full-text available
We studied a simple random recurrent inhibitory network. Despite its simplicity, the dynamics was so rich that activity patterns of neurons evolved with time without recurrence due to random recurrent connections among neurons. The sequence of activity patterns was generated by the trigger of an external signal, and the generation was stable agains...
Article
Full-text available
We studied the dynamics of a neural network which have both of recurrent excitatory and random inhibitory connections. Neurons started to become active when a relatively weak transient excitatory signal was presented and the activity sustained due to the recurrent excitatory connections. The sustained activity stopped when a strong transient signal...
Article
Using the intrinsic signal optical recording technique, we reconstructed the two-dimensional pattern of stimulus-evoked neuronal activities in the auditory cortex of anesthetized and paralyzed cats. The average magnitude of intrinsic signal in response to a pure tone stimulus increased steadily as the sound pressure level increased. A detailed anal...
Article
It is widely accepted that functional maps in the mammalian visual cortex such as ocular dominance columns and orientation columns are formed depending on neural activity. There is still, however, controversy on how much visual experience contributes to the map formation during development. In the present study, we address this issue from mathemati...
Article
Olfactory sensory neurons (OSNs) that express a given odorant receptor (OR) target their axons onto a few specific glomeruli in the olfactory bulb. Although the odorant receptor plays an indispensable role in olfactory axon targeting, the mechanisms underlying this guidance are largely unknown. In particular, there is much controversy regarding the...
Article
Humans have the capability of processing language and drawing inferences effortlessly. This raises a question as to how neurons in the brain process language and inference. Although connectionism is one of the promising candidates of methods for studying brain functions, it is not clear so far whether or not connectionist methods can be used to mod...
Article
The main objective of this study is to establish an intrinsic optical imaging method for visualizing functional architecture in the in vivo rodent visual cortex. For this purpose, we first determined the three optimal recording conditions for the imaging, viz., the depth of a focal plane, the wavelength of cortical illumination light, and the inten...
Article
We have developed a non-linear stochastic PDE (partial differential equation) model of a rat layer 2/3 somatosensory pyramidal neuron which approximates several of the dynamical properties of these cells. The model distinguishes telodendrites, a myelinated axon, initial segment, hillock, soma and a simplified dendritic tree. Distributions and prope...
Article
The orientation selectivity in the firing rate of neurons is one of the most well-known properties of neurons in the primary visual cortex. To understand the dynamical mechanism of the orientation tuning, we introduce a biologically plausible network for a hypercolumn and investigate dynamical responses of its columnar activities. Numerical simulat...