1
|
Mitoma H, Kakei S, Tanaka H, Manto M. Morphological and Functional Principles Governing the Plasticity Reserve in the Cerebellum: The Cortico-Deep Cerebellar Nuclei Loop Model. BIOLOGY 2023; 12:1435. [PMID: 37998034 PMCID: PMC10669841 DOI: 10.3390/biology12111435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/02/2023] [Accepted: 11/14/2023] [Indexed: 11/25/2023]
Abstract
Cerebellar reserve compensates for and restores functions lost through cerebellar damage. This is a fundamental property of cerebellar circuitry. Clinical studies suggest (1) the involvement of synaptic plasticity in the cerebellar cortex for functional compensation and restoration, and (2) that the integrity of the cerebellar reserve requires the survival and functioning of cerebellar nuclei. On the other hand, recent physiological studies have shown that the internal forward model, embedded within the cerebellum, controls motor accuracy in a predictive fashion, and that maintaining predictive control to achieve accurate motion ultimately promotes learning and compensatory processes. Furthermore, within the proposed framework of the Kalman filter, the current status is transformed into a predictive state in the cerebellar cortex (prediction step), whereas the predictive state and sensory feedback from the periphery are integrated into a filtered state at the cerebellar nuclei (filtering step). Based on the abovementioned clinical and physiological studies, we propose that the cerebellar reserve consists of two elementary mechanisms which are critical for cerebellar functions: the first is involved in updating predictions in the residual or affected cerebellar cortex, while the second acts by adjusting its updated forecasts with the current status in the cerebellar nuclei. Cerebellar cortical lesions would impair predictive behavior, whereas cerebellar nuclear lesions would impact on adjustments of neuronal commands. We postulate that the multiple forms of distributed plasticity at the cerebellar cortex and cerebellar nuclei are the neuronal events which allow the cerebellar reserve to operate in vivo. This cortico-deep cerebellar nuclei loop model attributes two complementary functions as the underpinnings behind cerebellar reserve.
Collapse
Affiliation(s)
- Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo 160-0023, Japan
| | - Shinji Kakei
- Department of Anatomy and Physiology, Jissen Women’s University, Tokyo 191-8510, Japan;
| | - Hirokazu Tanaka
- Faculty of Information Technology, Tokyo City University, Tokyo 158-8557, Japan;
| | - Mario Manto
- Cerebellar Ataxias Unit, Department of Neurology, Médiathèque Jean Jacquy, CHU-Charleroi, 6042 Charleroi, Belgium;
- Service des Neurosciences, University of Mons, 7000 Mons, Belgium
| |
Collapse
|
2
|
Todd NPM, Govender S, Keller PE, Colebatch JG. Electrophysiological activity from over the cerebellum and cerebrum during eye blink conditioning in human subjects. Physiol Rep 2023; 11:e15642. [PMID: 36971094 PMCID: PMC10041378 DOI: 10.14814/phy2.15642] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 02/22/2023] [Accepted: 02/24/2023] [Indexed: 03/29/2023] Open
Abstract
We report the results of an experiment in which electrophysiological activity was recorded from the human cerebellum and cerebrum in a sample of 14 healthy subjects before, during and after a classical eye blink conditioning procedure with an auditory tone as conditional stimulus and a maxillary nerve unconditional stimulus. The primary aim was to show changes in the cerebellum and cerebrum correlated with behavioral ocular responses. Electrodes recorded EMG and EOG at peri-ocular sites, EEG from over the frontal eye-fields and the electrocerebellogram (ECeG) from over the posterior fossa. Of the 14 subjects half strongly conditioned while the other half were resistant. We confirmed that conditionability was linked under our conditions to the personality dimension of extraversion-introversion. Inhibition of cerebellar activity was shown prior to the conditioned response, as predicted by Albus (1971). However, pausing in high frequency ECeG and the appearance of a contingent negative variation (CNV) in both central leads occurred in all subjects. These led us to conclude that while conditioned cerebellar pausing may be necessary, it is not sufficient alone to produce overt behavioral conditioning, implying the existence of another central mechanism. The outcomes of this experiment indicate the potential value of the noninvasive electrophysiology of the cerebellum.
Collapse
Affiliation(s)
- Neil P M Todd
- Department of Psychology, University of Exeter, Exeter, UK
- School of Clinical Medicine, Randwick Campus, UNSW, Sydney, New South Wales, Australia
| | - Sendhil Govender
- School of Clinical Medicine, Randwick Campus, UNSW, Sydney, New South Wales, Australia
- Neuroscience Research Australia, UNSW, Sydney, New South Wales, Australia
| | - Peter E Keller
- MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Penrith, New South Wales, Australia
- Center for Music in the Brain, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - James G Colebatch
- School of Clinical Medicine, Randwick Campus, UNSW, Sydney, New South Wales, Australia
- Neuroscience Research Australia, UNSW, Sydney, New South Wales, Australia
| |
Collapse
|
3
|
Structured cerebellar connectivity supports resilient pattern separation. Nature 2023; 613:543-549. [PMID: 36418404 DOI: 10.1038/s41586-022-05471-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 10/20/2022] [Indexed: 11/25/2022]
Abstract
The cerebellum is thought to help detect and correct errors between intended and executed commands1,2 and is critical for social behaviours, cognition and emotion3-6. Computations for motor control must be performed quickly to correct errors in real time and should be sensitive to small differences between patterns for fine error correction while being resilient to noise7. Influential theories of cerebellar information processing have largely assumed random network connectivity, which increases the encoding capacity of the network's first layer8-13. However, maximizing encoding capacity reduces the resilience to noise7. To understand how neuronal circuits address this fundamental trade-off, we mapped the feedforward connectivity in the mouse cerebellar cortex using automated large-scale transmission electron microscopy and convolutional neural network-based image segmentation. We found that both the input and output layers of the circuit exhibit redundant and selective connectivity motifs, which contrast with prevailing models. Numerical simulations suggest that these redundant, non-random connectivity motifs increase the resilience to noise at a negligible cost to the overall encoding capacity. This work reveals how neuronal network structure can support a trade-off between encoding capacity and redundancy, unveiling principles of biological network architecture with implications for the design of artificial neural networks.
Collapse
|
4
|
Gilmer JI, Farries MA, Kilpatrick Z, Delis I, Cohen JD, Person AL. An emergent temporal basis set robustly supports cerebellar time-series learning. J Neurophysiol 2023; 129:159-176. [PMID: 36416445 PMCID: PMC9990911 DOI: 10.1152/jn.00312.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 11/24/2022] Open
Abstract
The cerebellum is considered a "learning machine" essential for time interval estimation underlying motor coordination and other behaviors. Theoretical work has proposed that the cerebellum's input recipient structure, the granule cell layer (GCL), performs pattern separation of inputs that facilitates learning in Purkinje cells (P-cells). However, the relationship between input reformatting and learning has remained debated, with roles emphasized for pattern separation features from sparsification to decorrelation. We took a novel approach by training a minimalist model of the cerebellar cortex to learn complex time-series data from time-varying inputs, typical during movements. The model robustly produced temporal basis sets from these inputs, and the resultant GCL output supported better learning of temporally complex target functions than mossy fibers alone. Learning was optimized at intermediate threshold levels, supporting relatively dense granule cell activity, yet the key statistical features in GCL population activity that drove learning differed from those seen previously for classification tasks. These findings advance testable hypotheses for mechanisms of temporal basis set formation and predict that moderately dense population activity optimizes learning.NEW & NOTEWORTHY During movement, mossy fiber inputs to the cerebellum relay time-varying information with strong intrinsic relationships to ongoing movement. Are such mossy fibers signals sufficient to support Purkinje signals and learning? In a model, we show how the GCL greatly improves Purkinje learning of complex, temporally dynamic signals relative to mossy fibers alone. Learning-optimized GCL population activity was moderately dense, which retained intrinsic input variance while also performing pattern separation.
Collapse
Affiliation(s)
- Jesse I Gilmer
- Neuroscience Graduate Program, University of Colorado School of Medicine, Aurora, Colorado
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, Colorado
| | - Michael A Farries
- Knoebel Institute for Healthy Aging, University of Denver, Denver, Colorado
| | - Zachary Kilpatrick
- Department of Applied Mathematics, University of Colorado Boulder, Boulder, Colorado
| | - Ioannis Delis
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Jeremy D Cohen
- University of North Carolina Neuroscience Center, Chapel Hill, North Carolina
| | - Abigail L Person
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, Colorado
| |
Collapse
|
5
|
Bae H, Park SY, Kim SJ, Kim CE. Cerebellum as a kernel machine: A novel perspective on expansion recoding in granule cell layer. Front Comput Neurosci 2022; 16:1062392. [PMID: 36618271 PMCID: PMC9815768 DOI: 10.3389/fncom.2022.1062392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
Sensorimotor information provided by mossy fibers (MF) is mapped to high-dimensional space by a huge number of granule cells (GrC) in the cerebellar cortex's input layer. Significant studies have demonstrated the computational advantages and primary contributor of this expansion recoding. Here, we propose a novel perspective on the expansion recoding where each GrC serve as a kernel basis function, thereby the cerebellum can operate like a kernel machine that implicitly use high dimensional (even infinite) feature spaces. We highlight that the generation of kernel basis function is indeed biologically plausible scenario, considering that the key idea of kernel machine is to memorize important input patterns. We present potential regimes for developing kernels under constrained resources and discuss the advantages and disadvantages of each regime using various simulation settings.
Collapse
Affiliation(s)
- Hyojin Bae
- Department of Physiology, Gachon University College of Korean Medicine, Seongnam, South Korea
| | - Sa-Yoon Park
- Department of Physiology, Gachon University College of Korean Medicine, Seongnam, South Korea
| | - Sang Jeong Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, South Korea,*Correspondence: Sang Jeong Kim,
| | - Chang-Eop Kim
- Department of Physiology, Gachon University College of Korean Medicine, Seongnam, South Korea,Chang-Eop Kim,
| |
Collapse
|
6
|
Dasgupta S, Hattori D, Navlakha S. A neural theory for counting memories. Nat Commun 2022; 13:5961. [PMID: 36217003 PMCID: PMC9551066 DOI: 10.1038/s41467-022-33577-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 09/22/2022] [Indexed: 11/09/2022] Open
Abstract
Keeping track of the number of times different stimuli have been experienced is a critical computation for behavior. Here, we propose a theoretical two-layer neural circuit that stores counts of stimulus occurrence frequencies. This circuit implements a data structure, called a count sketch, that is commonly used in computer science to maintain item frequencies in streaming data. Our first model implements a count sketch using Hebbian synapses and outputs stimulus-specific frequencies. Our second model uses anti-Hebbian plasticity and only tracks frequencies within four count categories ("1-2-3-many"), which trades-off the number of categories that need to be distinguished with the potential ethological value of those categories. We show how both models can robustly track stimulus occurrence frequencies, thus expanding the traditional novelty-familiarity memory axis from binary to discrete with more than two possible values. Finally, we show that an implementation of the "1-2-3-many" count sketch exists in the insect mushroom body.
Collapse
Affiliation(s)
- Sanjoy Dasgupta
- Computer Science and Engineering Department, University of California San Diego, La Jolla, CA, 92037, USA
| | - Daisuke Hattori
- Department of Physiology, UT Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Saket Navlakha
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA.
| |
Collapse
|
7
|
Multi-target action of β-alanine protects cerebellar tissue from ischemic damage. Cell Death Dis 2022; 13:747. [PMID: 36038575 PMCID: PMC9424312 DOI: 10.1038/s41419-022-05159-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/26/2022] [Accepted: 08/03/2022] [Indexed: 01/21/2023]
Abstract
Brain ischemic stroke is among the leading causes of death and long-term disability. New treatments that alleviate brain cell damage until blood supply is restored are urgently required. The emerging focus of anti-stroke strategies has been on blood-brain-barrier permeable drugs that exhibit multiple sites of action. Here, we combine single-cell electrophysiology with live-cell imaging to find that β-Alanine (β-Ala) protects key physiological functions of brain cells that are exposed to acute stroke-mimicking conditions in ex vivo brain preparations. β-Ala exerts its neuroprotective action through several distinct pharmacological mechanisms, none of which alone could reproduce the neuroprotective effect. Since β-Ala crosses the blood-brain barrier and is part of a normal human diet, we suggest that it has a strong potential for acute stroke treatment and facilitation of recovery.
Collapse
|
8
|
Welniarz Q, Worbe Y, Gallea C. The Forward Model: A Unifying Theory for the Role of the Cerebellum in Motor Control and Sense of Agency. Front Syst Neurosci 2021; 15:644059. [PMID: 33935660 PMCID: PMC8082178 DOI: 10.3389/fnsys.2021.644059] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 02/22/2021] [Indexed: 12/13/2022] Open
Abstract
For more than two decades, there has been converging evidence for an essential role of the cerebellum in non-motor functions. The cerebellum is not only important in learning and sensorimotor processes, some growing evidences show its implication in conditional learning and reward, which allows building our expectations about behavioral outcomes. More recent work has demonstrated that the cerebellum is also required for the sense of agency, a cognitive process that allows recognizing an action as our own, suggesting that the cerebellum might serve as an interface between sensorimotor function and cognition. A unifying model that would explain the role of the cerebellum across these processes has not been fully established. Nonetheless, an important heritage was given by the field of motor control: the forward model theory. This theory stipulates that movements are controlled based on the constant interactions between our organism and its environment through feedforward and feedback loops. Feedforward loops predict what is going to happen, while feedback loops confront the prediction with what happened so that we can react accordingly. From an anatomical point of view, the cerebellum is at an ideal location at the interface between the motor and sensory systems, as it is connected to cerebral, striatal, and spinal entities via parallel loops, so that it can link sensory and motor systems with cognitive processes. Recent findings showing that the cerebellum participates in building the sense of agency as a predictive and comparator system will be reviewed together with past work on motor control within the context of the forward model theory.
Collapse
Affiliation(s)
- Quentin Welniarz
- INSERM U-1127, CNRS UMR 7225, Institut du Cerveau, Faculté de Médecine, Sorbonne Université, La Pitié Salpêtrière Hospital, Paris, France.,Movement Investigation and Therapeutics Team, ICM, Paris, France
| | - Yulia Worbe
- INSERM U-1127, CNRS UMR 7225, Institut du Cerveau, Faculté de Médecine, Sorbonne Université, La Pitié Salpêtrière Hospital, Paris, France.,Movement Investigation and Therapeutics Team, ICM, Paris, France.,Department of Neurophysiology, Saint-Antoine Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Cecile Gallea
- INSERM U-1127, CNRS UMR 7225, Institut du Cerveau, Faculté de Médecine, Sorbonne Université, La Pitié Salpêtrière Hospital, Paris, France.,Movement Investigation and Therapeutics Team, ICM, Paris, France
| |
Collapse
|
9
|
Kawato M, Ohmae S, Hoang H, Sanger T. 50 Years Since the Marr, Ito, and Albus Models of the Cerebellum. Neuroscience 2020; 462:151-174. [PMID: 32599123 DOI: 10.1016/j.neuroscience.2020.06.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/10/2020] [Accepted: 06/15/2020] [Indexed: 12/18/2022]
Abstract
Fifty years have passed since David Marr, Masao Ito, and James Albus proposed seminal models of cerebellar functions. These models share the essential concept that parallel-fiber-Purkinje-cell synapses undergo plastic changes, guided by climbing-fiber activities during sensorimotor learning. However, they differ in several important respects, including holistic versus complementary roles of the cerebellum, pattern recognition versus control as computational objectives, potentiation versus depression of synaptic plasticity, teaching signals versus error signals transmitted by climbing-fibers, sparse expansion coding by granule cells, and cerebellar internal models. In this review, we evaluate different features of the three models based on recent computational and experimental studies. While acknowledging that the three models have greatly advanced our understanding of cerebellar control mechanisms in eye movements and classical conditioning, we propose a new direction for computational frameworks of the cerebellum, that is, hierarchical reinforcement learning with multiple internal models.
Collapse
Affiliation(s)
- Mitsuo Kawato
- Brain Information Communication Research Group, Advanced Telecommunications Research Institutes International (ATR), Hikaridai 2-2-2, "Keihanna Science City", Kyoto 619-0288, Japan; Center for Advanced Intelligence Project (AIP), RIKEN, Nihonbashi Mitsui Building, 1-4-1 Nihonbashi, Chuo-ku, Tokyo 103-0027, Japan.
| | - Shogo Ohmae
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
| | - Huu Hoang
- Brain Information Communication Research Group, Advanced Telecommunications Research Institutes International (ATR), Hikaridai 2-2-2, "Keihanna Science City", Kyoto 619-0288, Japan
| | - Terry Sanger
- Department of Electrical Engineering, University of California, Irvine, 4207 Engineering Hall, Irvine CA 92697-2625, USA; Children's Hospital of Orange County, 1201 W La Veta Ave, Orange, CA 92868, USA.
| |
Collapse
|
10
|
Tanaka H, Ishikawa T, Lee J, Kakei S. The Cerebro-Cerebellum as a Locus of Forward Model: A Review. Front Syst Neurosci 2020; 14:19. [PMID: 32327978 PMCID: PMC7160920 DOI: 10.3389/fnsys.2020.00019] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 03/20/2020] [Indexed: 01/16/2023] Open
Abstract
This review surveys physiological, behavioral, and morphological evidence converging to the view of the cerebro-cerebellum as loci of internal forward models. The cerebro-cerebellum, the phylogenetically newest expansion in the cerebellum, receives convergent inputs from cortical, subcortical, and spinal sources, and is thought to perform the predictive computation for both motor control, motor learning, and cognitive functions. This predictive computation is known as an internal forward model. First, we elucidate the theoretical foundations of an internal forward model and its role in motor control and motor learning within the framework of the optimal feedback control model. Then, we discuss a neural mechanism that generates various patterns of outputs from the cerebro-cerebellum. Three lines of supporting evidence for the internal-forward-model hypothesis are presented in detail. First, we provide physiological evidence that the cerebellar outputs (activities of dentate nucleus cells) are predictive for the cerebellar inputs [activities of mossy fibers (MFs)]. Second, we provide behavioral evidence that a component of movement kinematics is predictive for target motion in control subjects but lags behind a target motion in patients with cerebellar ataxia. Third, we provide morphological evidence that the cerebellar cortex and the dentate nucleus receive separate MF projections, a prerequisite for optimal estimation. Finally, we speculate that the predictive computation in the cerebro-cerebellum could be deployed to not only motor control but also to non-motor, cognitive functions. This review concludes that the predictive computation of the internal forward model is the unifying algorithmic principle for understanding diverse functions played by the cerebro-cerebellum.
Collapse
Affiliation(s)
- Hirokazu Tanaka
- Japan Advanced Institute of Science and Technology, Nomi, Japan
| | | | | | - Shinji Kakei
- Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| |
Collapse
|