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Araki T, Hiragi T, Kuga N, Luo C, Andoh M, Sugao K, Nagata H, Sasaki T, Ikegaya Y, Koyama R. Microglia induce auditory dysfunction after status epilepticus in mice. Glia 2024; 72:274-288. [PMID: 37746760 DOI: 10.1002/glia.24472] [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: 01/26/2023] [Revised: 09/08/2023] [Accepted: 09/14/2023] [Indexed: 09/26/2023]
Abstract
Auditory dysfunction and increased neuronal activity in the auditory pathways have been reported in patients with temporal lobe epilepsy, but the cellular mechanisms involved are unknown. Here, we report that microglia play a role in the disinhibition of auditory pathways after status epilepticus in mice. We found that neuronal activity in the auditory pathways, including the primary auditory cortex and the medial geniculate body (MGB), was increased and auditory discrimination was impaired after status epilepticus. We further demonstrated that microglia reduced inhibitory synapses on MGB relay neurons over an 8-week period after status epilepticus, resulting in auditory pathway hyperactivity. In addition, we found that local removal of microglia from the MGB attenuated the increase in c-Fos+ relay neurons and improved auditory discrimination. These findings reveal that thalamic microglia are involved in auditory dysfunction in epilepsy.
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Affiliation(s)
- Tasuku Araki
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Toshimitsu Hiragi
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Nahoko Kuga
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Cong Luo
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Megumi Andoh
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | | | | | - Takuya Sasaki
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
- Institute for AI and Beyond, The University of Tokyo, Tokyo, Japan
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka, Japan
| | - Ryuta Koyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
- Institute for AI and Beyond, The University of Tokyo, Tokyo, Japan
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2
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Palchaudhuri S, Osypenko D, Schneggenburger R. Fear Learning: An Evolving Picture for Plasticity at Synaptic Afferents to the Amygdala. Neuroscientist 2024; 30:87-104. [PMID: 35822657 DOI: 10.1177/10738584221108083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Unraveling the neuronal mechanisms of fear learning might allow neuroscientists to make links between a learned behavior and the underlying plasticity at specific synaptic connections. In fear learning, an innocuous sensory event such as a tone (called the conditioned stimulus, CS) acquires an emotional value when paired with an aversive outcome (unconditioned stimulus, US). Here, we review earlier studies that have shown that synaptic plasticity at thalamic and cortical afferents to the lateral amygdala (LA) is critical for the formation of auditory-cued fear memories. Despite the early progress, it has remained unclear whether there are separate synaptic inputs that carry US information to the LA to act as a teaching signal for plasticity at CS-coding synapses. Recent findings have begun to fill this gap by showing, first, that thalamic and cortical auditory afferents can also carry US information; second, that the release of neuromodulators contributes to US-driven teaching signals; and third, that synaptic plasticity additionally happens at connections up- and downstream of the LA. Together, a picture emerges in which coordinated synaptic plasticity in serial and parallel circuits enables the formation of a finely regulated fear memory.
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Affiliation(s)
- Shriya Palchaudhuri
- Laboratory of Synaptic Mechanisms, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Denys Osypenko
- Laboratory of Synaptic Mechanisms, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ralf Schneggenburger
- Laboratory of Synaptic Mechanisms, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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3
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Jourde HR, Merlo R, Brooks M, Rowe M, Coffey EBJ. The neurophysiology of closed-loop auditory stimulation in sleep: A magnetoencephalography study. Eur J Neurosci 2024; 59:613-640. [PMID: 37675803 DOI: 10.1111/ejn.16132] [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: 12/23/2022] [Revised: 08/01/2023] [Accepted: 08/08/2023] [Indexed: 09/08/2023]
Abstract
Closed-loop auditory stimulation (CLAS) is a brain modulation technique in which sounds are timed to enhance or disrupt endogenous neurophysiological events. CLAS of slow oscillation up-states in sleep is becoming a popular tool to study and enhance sleep's functions, as it increases slow oscillations, evokes sleep spindles and enhances memory consolidation of certain tasks. However, few studies have examined the specific neurophysiological mechanisms involved in CLAS, in part because of practical limitations to available tools. To evaluate evidence for possible models of how sound stimulation during brain up-states alters brain activity, we simultaneously recorded electro- and magnetoencephalography in human participants who received auditory stimulation across sleep stages. We conducted a series of analyses that test different models of pathways through which CLAS of slow oscillations may affect widespread neural activity that have been suggested in literature, using spatial information, timing and phase relationships in the source-localized magnetoencephalography data. The results suggest that auditory information reaches ventral frontal lobe areas via non-lemniscal pathways. From there, a slow oscillation is created and propagated. We demonstrate that while the state of excitability of tissue in auditory cortex and frontal ventral regions shows some synchrony with the electroencephalography (EEG)-recorded up-states that are commonly used for CLAS, it is the state of ventral frontal regions that is most critical for slow oscillation generation. Our findings advance models of how CLAS leads to enhancement of slow oscillations, sleep spindles and associated cognitive benefits and offer insight into how the effectiveness of brain stimulation techniques can be improved.
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Affiliation(s)
- Hugo R Jourde
- Concordia University, Montreal, Quebec, Canada
- International Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Quebec, Canada
- Centre for Research on Brain, Language and Music (CRBLM), Montreal, Quebec, Canada
- Quebec Bio-Imaging Network (QBIN), Sherbrooke, Quebec, Canada
| | | | - Mary Brooks
- Concordia University, Montreal, Quebec, Canada
- International Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Quebec, Canada
- Centre for Research on Brain, Language and Music (CRBLM), Montreal, Quebec, Canada
- Quebec Bio-Imaging Network (QBIN), Sherbrooke, Quebec, Canada
| | | | - Emily B J Coffey
- Concordia University, Montreal, Quebec, Canada
- International Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Quebec, Canada
- Centre for Research on Brain, Language and Music (CRBLM), Montreal, Quebec, Canada
- Quebec Bio-Imaging Network (QBIN), Sherbrooke, Quebec, Canada
- McGill University, Montreal, Quebec, Canada
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4
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Ricciardi F, Márquez C. The neural circuit that makes maternal mice respond to pups' cries. Nature 2023; 621:693-694. [PMID: 37735608 DOI: 10.1038/d41586-023-02545-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
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Kouvaros S, Bizup B, Solis O, Kumar M, Ventriglia E, Curry FP, Michaelides M, Tzounopoulos T. A CRE/DRE dual recombinase transgenic mouse reveals synaptic zinc-mediated thalamocortical neuromodulation. SCIENCE ADVANCES 2023; 9:eadf3525. [PMID: 37294760 PMCID: PMC10256168 DOI: 10.1126/sciadv.adf3525] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 05/05/2023] [Indexed: 06/11/2023]
Abstract
Synaptic zinc is a neuromodulator that shapes synaptic transmission and sensory processing. The maintenance of synaptic zinc is dependent on the vesicular zinc transporter, ZnT3. Hence, the ZnT3 knockout mouse has been a key tool for studying the mechanisms and functions of synaptic zinc. However, the use of this constitutive knockout mouse has notable limitations, including developmental, compensatory, and brain and cell type specificity issues. To overcome these limitations, we developed and characterized a dual recombinase transgenic mouse, which combines the Cre and Dre recombinase systems. This mouse allows for tamoxifen-inducible Cre-dependent expression of exogenous genes or knockout of floxed genes in ZnT3-expressing neurons and DreO-dependent region and cell type-specific conditional ZnT3 knockout in adult mice. Using this system, we reveal a neuromodulatory mechanism whereby zinc release from thalamic neurons modulates N-methyl-d-aspartate receptor activity in layer 5 pyramidal tract neurons, unmasking previously unknown features of cortical neuromodulation.
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Affiliation(s)
- Stylianos Kouvaros
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Brandon Bizup
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Oscar Solis
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Manoj Kumar
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Emilya Ventriglia
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Fallon P. Curry
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Thanos Tzounopoulos
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261, USA
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Gandhi T, Canepa CR, Adeyelu TT, Adeniyi PA, Lee CC. Neuroanatomical Alterations in the CNTNAP2 Mouse Model of Autism Spectrum Disorder. Brain Sci 2023; 13:891. [PMID: 37371370 DOI: 10.3390/brainsci13060891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 05/23/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
Autism spectrum disorder (ASD) is associated with neurodevelopmental alterations, including atypical forebrain cellular organization. Mutations in several ASD-related genes often result in cerebral cortical anomalies, such as the abnormal developmental migration of excitatory pyramidal cells and the malformation of inhibitory neuronal circuitry. Notably here, mutations in the CNTNAP2 gene result in ectopic superficial cortical neurons stalled in lower cortical layers and alterations to the balance of cortical excitation and inhibition. However, the broader circuit-level implications of these findings have not been previously investigated. Therefore, we assessed whether ectopic cortical neurons in CNTNAP2 mutant mice form aberrant connections with higher-order thalamic nuclei, potentially accounting for some autistic behaviors, such as repetitive and hyperactive behaviors. Furthermore, we assessed whether the development of parvalbumin-positive (PV) cortical interneurons and their specialized matrix support structures, called perineuronal nets (PNNs), were altered in these mutant mice. We found alterations in both ectopic neuronal connectivity and in the development of PNNs, PV neurons and PNNs enwrapping PV neurons in various sensory cortical regions and at different postnatal ages in the CNTNAP2 mutant mice, which likely lead to some of the cortical excitation/inhibition (E/I) imbalance associated with ASD. These findings suggest neuroanatomical alterations in cortical regions that underlie the emergence of ASD-related behaviors in this mouse model of the disorder.
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Affiliation(s)
- Tanya Gandhi
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70806, USA
| | - Cade R Canepa
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70806, USA
| | - Tolulope T Adeyelu
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70806, USA
| | - Philip A Adeniyi
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70806, USA
| | - Charles C Lee
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70806, USA
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Willmore BDB, King AJ. Adaptation in auditory processing. Physiol Rev 2023; 103:1025-1058. [PMID: 36049112 PMCID: PMC9829473 DOI: 10.1152/physrev.00011.2022] [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] [Indexed: 01/21/2023] Open
Abstract
Adaptation is an essential feature of auditory neurons, which reduces their responses to unchanging and recurring sounds and allows their response properties to be matched to the constantly changing statistics of sounds that reach the ears. As a consequence, processing in the auditory system highlights novel or unpredictable sounds and produces an efficient representation of the vast range of sounds that animals can perceive by continually adjusting the sensitivity and, to a lesser extent, the tuning properties of neurons to the most commonly encountered stimulus values. Together with attentional modulation, adaptation to sound statistics also helps to generate neural representations of sound that are tolerant to background noise and therefore plays a vital role in auditory scene analysis. In this review, we consider the diverse forms of adaptation that are found in the auditory system in terms of the processing levels at which they arise, the underlying neural mechanisms, and their impact on neural coding and perception. We also ask what the dynamics of adaptation, which can occur over multiple timescales, reveal about the statistical properties of the environment. Finally, we examine how adaptation to sound statistics is influenced by learning and experience and changes as a result of aging and hearing loss.
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Affiliation(s)
- Ben D. B. Willmore
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Andrew J. King
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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Leppla CA, Keyes LR, Glober G, Matthews GA, Batra K, Jay M, Feng Y, Chen HS, Mills F, Delahanty J, Olson JM, Nieh EH, Namburi P, Wildes C, Wichmann R, Beyeler A, Kimchi EY, Tye KM. Thalamus sends information about arousal but not valence to the amygdala. Psychopharmacology (Berl) 2023; 240:477-499. [PMID: 36522481 PMCID: PMC9928937 DOI: 10.1007/s00213-022-06284-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 11/23/2022] [Indexed: 12/23/2022]
Abstract
RATIONALE The basolateral amygdala (BLA) and medial geniculate nucleus of the thalamus (MGN) have both been shown to be necessary for the formation of associative learning. While the role that the BLA plays in this process has long been emphasized, the MGN has been less well-studied and surrounded by debate regarding whether the relay of sensory information is active or passive. OBJECTIVES We seek to understand the role the MGN has within the thalamoamgydala circuit in the formation of associative learning. METHODS Here, we use optogenetics and in vivo electrophysiological recordings to dissect the MGN-BLA circuit and explore the specific subpopulations for evidence of learning and synthesis of information that could impact downstream BLA encoding. We employ various machine learning techniques to investigate function within neural subpopulations. We introduce a novel method to investigate tonic changes across trial-by-trial structure, which offers an alternative approach to traditional trial-averaging techniques. RESULTS We find that the MGN appears to encode arousal but not valence, unlike the BLA which encodes for both. We find that the MGN and the BLA appear to react differently to expected and unexpected outcomes; the BLA biased responses toward reward prediction error and the MGN focused on anticipated punishment. We uncover evidence of tonic changes by visualizing changes across trials during inter-trial intervals (baseline epochs) for a subset of cells. CONCLUSION We conclude that the MGN-BLA projector population acts as both filter and transferer of information by relaying information about the salience of cues to the amygdala, but these signals are not valence-specified.
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Affiliation(s)
- Chris A Leppla
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Laurel R Keyes
- Howard Hughes Medical Institute, The Salk Institute, La Jolla, CA, 92037, USA
- SNL-KT, Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Gordon Glober
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Gillian A Matthews
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
- SNL-KT, Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Kanha Batra
- SNL-KT, Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Maya Jay
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Yu Feng
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Hannah S Chen
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Fergil Mills
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
- SNL-KT, Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Jeremy Delahanty
- Howard Hughes Medical Institute, The Salk Institute, La Jolla, CA, 92037, USA
- SNL-KT, Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Jacob M Olson
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Edward H Nieh
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Praneeth Namburi
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Craig Wildes
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Romy Wichmann
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
- SNL-KT, Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Anna Beyeler
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Eyal Y Kimchi
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA
| | - Kay M Tye
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA, 02139, USA.
- Howard Hughes Medical Institute, The Salk Institute, La Jolla, CA, 92037, USA.
- SNL-KT, Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA.
- Kavli Institute for Brain and Mind, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA.
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9
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Evolution of brain functional plasticity associated with increasing symptom severity in degenerative cervical myelopathy. EBioMedicine 2022; 84:104255. [PMID: 36116214 PMCID: PMC9483733 DOI: 10.1016/j.ebiom.2022.104255] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Advanced imaging modalities have helped elucidate the cerebral alterations associated with neurological impairment caused by degenerative cervical myelopathy (DCM), but it remains unknown how brain functional network changes at different stages of myelopathy severity in DCM patients, and if patterns in network connectivity can be used to predict transition to more myelopathic stages of DCM. METHODS This pilot cross-sectional study, which involves the collection of resting-state functional MRI (rs-fMRI) images and the modified Japanese Orthopedic Association (mJOA) score, enrolled 116 participants (99 patients and 17 healthy controls) from 2016 to 2021. The patient cohort included 21patients with asymptomatic spinal cord compression, 48 mild DCM patients, and 20 moderate or severe DCM patients. Functional connectivity networks were quantified for all participants, and the transition matrices were quantified to determine the differences in network connectivity through increasingly myelopathic stages of DCM. Additionally, a link prediction model was used to determine whether more severe stages of DCM can be predicted from less symptomatic stages using the transition matrices. FINDINGS Results indicated interruptions in most connections within the sensorimotor network in conjunction with spinal cord compression, while compensatory connectivity was observed within and between primary and secondary sensorimotor regions, subcortical regions, visuospatial regions including the cuneus, as well as the brainstem and cerebellum. A link prediction model achieved an excellent predictive performance in estimating connectivity of more severe myelopathic stages of DCM, with the highest area under the receiver operator curve (AUC) of 0.927 for predicting mild DCM from patients with asymptomatic spinal cord compression. INTERPRETATION A series of predictable changes in functional connectivity occur throughout the stages of DCM pathogenesis. The brainstem and cerebellum appear highly influential in optimizing sensorimotor function during worsening myelopathy. The link predication model can inclusively estimate brain alterations associated with myelopathy severity. FUNDING NIH/NINDS grants (1R01NS078494-01A1, and 2R01NS078494).
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Marks WD, Yokose J, Kitamura T, Ogawa SK. Neuronal Ensembles Organize Activity to Generate Contextual Memory. Front Behav Neurosci 2022; 16:805132. [PMID: 35368306 PMCID: PMC8965349 DOI: 10.3389/fnbeh.2022.805132] [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: 10/29/2021] [Accepted: 02/14/2022] [Indexed: 11/17/2022] Open
Abstract
Contextual learning is a critical component of episodic memory and important for living in any environment. Context can be described as the attributes of a location that are not the location itself. This includes a variety of non-spatial information that can be derived from sensory systems (sounds, smells, lighting, etc.) and internal state. In this review, we first address the behavioral underpinnings of contextual memory and the development of context memory theory, with a particular focus on the contextual fear conditioning paradigm as a means of assessing contextual learning and the underlying processes contributing to it. We then present the various neural centers that play roles in contextual learning. We continue with a discussion of the current knowledge of the neural circuitry and physiological processes that underlie contextual representations in the Entorhinal cortex-Hippocampal (EC-HPC) circuit, as the most well studied contributor to contextual memory, focusing on the role of ensemble activity as a representation of context with a description of remapping, and pattern separation and completion in the processing of contextual information. We then discuss other critical regions involved in contextual memory formation and retrieval. We finally consider the engram assembly as an indicator of stored contextual memories and discuss its potential contribution to contextual memory.
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Affiliation(s)
- William D. Marks
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Jun Yokose
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Takashi Kitamura
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Sachie K. Ogawa
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States
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11
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Cook JR, Li H, Nguyen B, Huang HH, Mahdavian P, Kirchgessner MA, Strassmann P, Engelhardt M, Callaway EM, Jin X. Secondary auditory cortex mediates a sensorimotor mechanism for action timing. Nat Neurosci 2022; 25:330-344. [PMID: 35260862 DOI: 10.1038/s41593-022-01025-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 01/26/2022] [Indexed: 01/08/2023]
Abstract
The ability to accurately determine when to perform an action is a fundamental brain function and vital to adaptive behavior. The behavioral mechanism and neural circuit for action timing, however, remain largely unknown. Using a new, self-paced action timing task in mice, we found that deprivation of auditory, but not somatosensory or visual input, disrupts learned action timing. The hearing effect was dependent on the auditory feedback derived from the animal's own actions, rather than passive environmental cues. Neuronal activity in the secondary auditory cortex was found to be both correlated with and necessary for the proper execution of learned action timing. Closed-loop, action-dependent optogenetic stimulation of the specific task-related neuronal population within the secondary auditory cortex rescued the key features of learned action timing under auditory deprivation. These results unveil a previously underappreciated sensorimotor mechanism in which the secondary auditory cortex transduces self-generated audiomotor feedback to control action timing.
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Affiliation(s)
- Jonathan R Cook
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA.,Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, USA.,Champalimaud Centre for the Unknown, Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal
| | - Hao Li
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Bella Nguyen
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Hsiang-Hsuan Huang
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA.,Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, USA
| | - Payaam Mahdavian
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Megan A Kirchgessner
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, USA.,Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA.,Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY, USA
| | - Patrick Strassmann
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA.,Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, USA
| | - Max Engelhardt
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Edward M Callaway
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Xin Jin
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA. .,Center for Motor Control and Disease, Key Laboratory of Brain Functional Genomics, East China Normal University, Shanghai, China. .,NYU-ECNU Institute of Brain and Cognitive Science, New York University Shanghai, Shanghai, China.
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12
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Adeyelu T, Gandhi T, Lee CC. Crossed Connections From Insular Cortex to the Contralateral Thalamus. Front Neural Circuits 2021; 15:710925. [PMID: 34949990 PMCID: PMC8688809 DOI: 10.3389/fncir.2021.710925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 11/10/2021] [Indexed: 11/13/2022] Open
Abstract
Sensory information in all modalities, except olfaction, is processed at the level of the thalamus before subsequent transmission to the cerebral cortex. This incoming sensory stream is refined and modulated in the thalamus by numerous descending corticothalamic projections originating in layer 6 that ultimately alter the sensitivity and selectivity for sensory features. In general, these sensory thalamo-cortico-thalamic loops are considered strictly unilateral, i.e., no contralateral crosstalk between cortex and thalamus. However, in contrast to this canonical view, we characterize here a prominent contralateral corticothalamic projection originating in the insular cortex, utilizing both retrograde tracing and cre-lox mediated viral anterograde tracing strategies with the Ntsr1-Cre transgenic mouse line. From our studies, we find that the insular contralateral corticothalamic projection originates from a separate population of layer 6 neurons than the ipsilateral corticothalamic projection. Furthermore, the contralateral projection targets a topographically distinct subregion of the thalamus than the ipsilateral projection. These findings suggest a unique bilateral mechanism for the top-down refinement of ascending sensory information.
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Affiliation(s)
| | | | - Charles C. Lee
- Department of Comparative Biomedical Sciences, Louisiana State University, School of Veterinary Medicine, Baton Rouge, LA, United States
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13
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Mease RA, Gonzalez AJ. Corticothalamic Pathways From Layer 5: Emerging Roles in Computation and Pathology. Front Neural Circuits 2021; 15:730211. [PMID: 34566583 PMCID: PMC8458899 DOI: 10.3389/fncir.2021.730211] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 08/10/2021] [Indexed: 11/29/2022] Open
Abstract
Large portions of the thalamus receive strong driving input from cortical layer 5 (L5) neurons but the role of this important pathway in cortical and thalamic computations is not well understood. L5-recipient "higher-order" thalamic regions participate in cortico-thalamo-cortical (CTC) circuits that are increasingly recognized to be (1) anatomically and functionally distinct from better-studied "first-order" CTC networks, and (2) integral to cortical activity related to learning and perception. Additionally, studies are beginning to elucidate the clinical relevance of these networks, as dysfunction across these pathways have been implicated in several pathological states. In this review, we highlight recent advances in understanding L5 CTC networks across sensory modalities and brain regions, particularly studies leveraging cell-type-specific tools that allow precise experimental access to L5 CTC circuits. We aim to provide a focused and accessible summary of the anatomical, physiological, and computational properties of L5-originating CTC networks, and outline their underappreciated contribution in pathology. We particularly seek to connect single-neuron and synaptic properties to network (dys)function and emerging theories of cortical computation, and highlight information processing in L5 CTC networks as a promising focus for computational studies.
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Affiliation(s)
- Rebecca A. Mease
- Institute of Physiology and Pathophysiology, Medical Biophysics, Heidelberg University, Heidelberg, Germany
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14
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Homma NY, Bajo VM. Lemniscal Corticothalamic Feedback in Auditory Scene Analysis. Front Neurosci 2021; 15:723893. [PMID: 34489635 PMCID: PMC8417129 DOI: 10.3389/fnins.2021.723893] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/30/2021] [Indexed: 12/15/2022] Open
Abstract
Sound information is transmitted from the ear to central auditory stations of the brain via several nuclei. In addition to these ascending pathways there exist descending projections that can influence the information processing at each of these nuclei. A major descending pathway in the auditory system is the feedback projection from layer VI of the primary auditory cortex (A1) to the ventral division of medial geniculate body (MGBv) in the thalamus. The corticothalamic axons have small glutamatergic terminals that can modulate thalamic processing and thalamocortical information transmission. Corticothalamic neurons also provide input to GABAergic neurons of the thalamic reticular nucleus (TRN) that receives collaterals from the ascending thalamic axons. The balance of corticothalamic and TRN inputs has been shown to refine frequency tuning, firing patterns, and gating of MGBv neurons. Therefore, the thalamus is not merely a relay stage in the chain of auditory nuclei but does participate in complex aspects of sound processing that include top-down modulations. In this review, we aim (i) to examine how lemniscal corticothalamic feedback modulates responses in MGBv neurons, and (ii) to explore how the feedback contributes to auditory scene analysis, particularly on frequency and harmonic perception. Finally, we will discuss potential implications of the role of corticothalamic feedback in music and speech perception, where precise spectral and temporal processing is essential.
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Affiliation(s)
- Natsumi Y. Homma
- Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, CA, United States
- Coleman Memorial Laboratory, Department of Otolaryngology – Head and Neck Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Victoria M. Bajo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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15
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Development of Auditory Cortex Circuits. J Assoc Res Otolaryngol 2021; 22:237-259. [PMID: 33909161 DOI: 10.1007/s10162-021-00794-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 03/03/2021] [Indexed: 02/03/2023] Open
Abstract
The ability to process and perceive sensory stimuli is an essential function for animals. Among the sensory modalities, audition is crucial for communication, pleasure, care for the young, and perceiving threats. The auditory cortex (ACtx) is a key sound processing region that combines ascending signals from the auditory periphery and inputs from other sensory and non-sensory regions. The development of ACtx is a protracted process starting prenatally and requires the complex interplay of molecular programs, spontaneous activity, and sensory experience. Here, we review the development of thalamic and cortical auditory circuits during pre- and early post-natal periods.
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16
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Chengetanai S, Bhagwandin A, Bertelsen MF, Hård T, Hof PR, Spocter MA, Manger PR. The brain of the African wild dog. III. The auditory system. J Comp Neurol 2020; 528:3229-3244. [PMID: 32678456 DOI: 10.1002/cne.24989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 07/13/2020] [Accepted: 07/14/2020] [Indexed: 11/05/2022]
Abstract
The large external pinnae and extensive vocal repertoire of the African wild dog (Lycaon pictus) has led to the assumption that the auditory system of this unique canid may be specialized. Here, using cytoarchitecture, myeloarchitecture, and a range of immunohistochemical stains, we describe the systems-level anatomy of the auditory system of the African wild dog. We observed the cochlear nuclear complex, superior olivary nuclear complex, lateral lemniscus, inferior colliculus, medial geniculate body, and auditory cortex all being in their expected locations, and exhibiting the standard subdivisions of this system. While located in the ectosylvian gyri, the auditory cortex includes several areas, resembling the parcellation observed in cats and ferrets, although not all of the auditory areas known from these species could be identified in the African wild dog. These observations suggest that, broadly speaking, the systems-level anatomy of the auditory system, and by extension the processing of auditory information, within the brain of the African wild dog closely resembles that observed in other carnivores. Our findings indicate that it is likely that the extraction of the semantic content of the vocalizations of African wild dogs, and the behaviors generated, occurs beyond the classically defined auditory system, in limbic or association neocortical regions involved in cognitive functions. Thus, to obtain a deeper understanding of how auditory stimuli are processed, and how communication is achieved, in the African wild dog compared to other canids, cortical regions beyond the primary sensory areas will need to be examined in detail.
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Affiliation(s)
- Samson Chengetanai
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Mads F Bertelsen
- Center for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark
| | | | - Patrick R Hof
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,New York Consortium in Evolutionary Primatology, New York, New York, USA
| | - Muhammad A Spocter
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa.,Department of Anatomy, Des Moines University, Des Moines, Iowa, USA
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
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17
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Srivastava HK, Bandyopadhyay S. Parallel Lemniscal and Non-Lemniscal Sources Control Auditory Responses in the Orbitofrontal Cortex (OFC). eNeuro 2020; 7:ENEURO.0121-20.2020. [PMID: 32753369 PMCID: PMC7545433 DOI: 10.1523/eneuro.0121-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/29/2020] [Accepted: 05/10/2020] [Indexed: 12/14/2022] Open
Abstract
The orbitofrontal cortex (OFC) controls flexible behavior through stimulus value updating based on stimulus outcome associations, allowing seamless navigation in dynamic sensory environments with changing contingencies. Sensory cue driven responses, primarily studied through behavior, exist in the OFC. However, OFC neurons' sensory response properties, particularly auditory, are unknown in the mouse, a genetically tractable animal. We show that mouse OFC single neurons have unique auditory response properties showing pure oddball detection and long timescales of adaptation resulting in stimulus-history dependence. Further, we show that OFC auditory responses are shaped by two parallel sources in the auditory thalamus, lemniscal and non-lemniscal. The latter underlies a large component of the observed oddball detection and additionally controls persistent activity in the OFC through the amygdala. The deviant selectivity can serve as a signal for important changes in the auditory environment. Such signals, if coupled with persistent activity, obtained by disinhibitory control from the non-lemniscal auditory thalamus or amygdala, will allow for associations with a delayed outcome related signal, like reward prediction error, and potentially forms the basis of updating stimulus outcome associations in the OFC. Thus, the baseline sensory responses allow the behavioral requirement-based response modification through relevant inputs from other structures related to reward, punishment, or memory. Thus, alterations in these responses in neurologic disorders can lead to behavioral deficits.
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Affiliation(s)
- Hemant K Srivastava
- Advanced Technology Development Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Sharba Bandyopadhyay
- Advanced Technology Development Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
- Department of Electronics and Electrical Communication Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
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18
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Belekhova MG, Kenigfest NB, Chmykhova NM. Evolutionary Formation and Functional
Significance
of the Core–Belt Pattern of Neural Organization of Rostral Auditory
Centers in Vertebrates. J EVOL BIOCHEM PHYS+ 2020. [DOI: 10.1134/s0022093020040018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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19
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Gilad A, Maor I, Mizrahi A. Learning-related population dynamics in the auditory thalamus. eLife 2020; 9:56307. [PMID: 32639231 PMCID: PMC7371423 DOI: 10.7554/elife.56307] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 07/07/2020] [Indexed: 12/20/2022] Open
Abstract
Learning to associate sensory stimuli with a chosen action involves a dynamic interplay between cortical and thalamic circuits. While the cortex has been widely studied in this respect, how the thalamus encodes learning-related information is still largely unknown. We studied learning-related activity in the medial geniculate body (MGB; Auditory thalamus), targeting mainly the dorsal and medial regions. Using fiber photometry, we continuously imaged population calcium dynamics as mice learned a go/no-go auditory discrimination task. The MGB was tuned to frequency and responded to cognitive features like the choice of the mouse within several hundred milliseconds. Encoding of choice in the MGB increased with learning, and was highly correlated with the learning curves of the mice. MGB also encoded motor parameters of the mouse during the task. These results provide evidence that the MGB encodes task- motor- and learning-related information.
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Affiliation(s)
- Ariel Gilad
- Department of Medical Neurobiology, Institute for Medical Research Israel Canada, Faculty of Medicine, The Hebrew University, Jerusalem, Israel.,The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ido Maor
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Adi Mizrahi
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Neurobiology, The Hebrew University of Jerusalem, Jerusalem, Israel
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20
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Tasaka GI, Feigin L, Maor I, Groysman M, DeNardo LA, Schiavo JK, Froemke RC, Luo L, Mizrahi A. The Temporal Association Cortex Plays a Key Role in Auditory-Driven Maternal Plasticity. Neuron 2020; 107:566-579.e7. [PMID: 32473095 DOI: 10.1016/j.neuron.2020.05.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 01/29/2020] [Accepted: 05/01/2020] [Indexed: 11/24/2022]
Abstract
Mother-infant bonding develops rapidly following parturition and is accompanied by changes in sensory perception and behavior. Here, we study how ultrasonic vocalizations (USVs) are represented in the brain of mothers. Using a mouse line that allows temporally controlled genetic access to active neurons, we find that the temporal association cortex (TeA) in mothers exhibits robust USV responses. Rabies tracing from USV-responsive neurons reveals extensive subcortical and cortical inputs into TeA. A particularly dominant cortical source of inputs is the primary auditory cortex (A1), suggesting strong A1-to-TeA connectivity. Chemogenetic silencing of USV-responsive neurons in TeA impairs auditory-driven maternal preference in a pup-retrieval assay. Furthermore, dense extracellular recordings from awake mice reveal changes of both single-neuron and population responses to USVs in TeA, improving discriminability of pup calls in mothers compared with naive females. These data indicate that TeA plays a key role in encoding and perceiving pup cries during motherhood.
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Affiliation(s)
- Gen-Ichi Tasaka
- Department of Neurobiology, The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Libi Feigin
- Department of Neurobiology, The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Ido Maor
- Department of Neurobiology, The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Maya Groysman
- Department of Neurobiology, The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Laura A DeNardo
- Department of Biology, Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Jennifer K Schiavo
- Skirball Institute for Biomolecular Medicine, Neuroscience Institute, and Department of Otolaryngology, New York University School of Medicine, New York, NY 10016, USA
| | - Robert C Froemke
- Skirball Institute for Biomolecular Medicine, Neuroscience Institute, and Department of Otolaryngology, New York University School of Medicine, New York, NY 10016, USA
| | - Liqun Luo
- Department of Biology, Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Adi Mizrahi
- Department of Neurobiology, The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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21
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Ohga S, Tsukano H, Horie M, Terashima H, Nishio N, Kubota Y, Takahashi K, Hishida R, Takebayashi H, Shibuki K. Direct Relay Pathways from Lemniscal Auditory Thalamus to Secondary Auditory Field in Mice. Cereb Cortex 2019; 28:4424-4439. [PMID: 30272122 PMCID: PMC6215474 DOI: 10.1093/cercor/bhy234] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 09/01/2018] [Indexed: 12/19/2022] Open
Abstract
Tonotopy is an essential functional organization in the mammalian auditory cortex, and its source in the primary auditory cortex (A1) is the incoming frequency-related topographical projections from the ventral division of the medial geniculate body (MGv). However, circuits that relay this functional organization to higher-order regions such as the secondary auditory field (A2) have yet to be identified. Here, we discovered a new pathway that projects directly from MGv to A2 in mice. Tonotopy was established in A2 even when primary fields including A1 were removed, which indicates that tonotopy in A2 can be established solely by thalamic input. Moreover, the structural nature of differing thalamocortical connections was consistent with the functional organization of the target regions in the auditory cortex. Retrograde tracing revealed that the region of MGv input to a local area in A2 was broader than the region of MGv input to A1. Consistent with this anatomy, two-photon calcium imaging revealed that neuronal responses in the thalamocortical recipient layer of A2 showed wider bandwidth and greater heterogeneity of the best frequency distribution than those of A1. The current study demonstrates a new thalamocortical pathway that relays frequency information to A2 on the basis of the MGv compartmentalization.
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Affiliation(s)
- Shinpei Ohga
- Department of Neurophysiology, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Japan
| | - Hiroaki Tsukano
- Department of Neurophysiology, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Japan
| | - Masao Horie
- Department of Morphological Sciences, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, Japan
| | - Hiroki Terashima
- NTT Communication Science Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa, Japan
| | - Nana Nishio
- Department of Neurophysiology, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Japan
| | - Yamato Kubota
- Department of Otolaryngology, Graduate School of Medicine and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Japan
| | - Kuniyuki Takahashi
- Department of Otolaryngology, Graduate School of Medicine and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Japan
| | - Ryuichi Hishida
- Department of Neurophysiology, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Japan
| | - Hirohide Takebayashi
- Division of Neurobiology and Anatomy, Graduate School of Medicine and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Japan
| | - Katsuei Shibuki
- Department of Neurophysiology, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata, Japan
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22
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Rudner M, Seeto M, Keidser G, Johnson B, Rönnberg J. Poorer Speech Reception Threshold in Noise Is Associated With Lower Brain Volume in Auditory and Cognitive Processing Regions. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2019; 62:1117-1130. [PMID: 31026199 DOI: 10.1044/2018_jslhr-h-ascc7-18-0142] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Purpose Hearing loss is associated with changes in brain volume in regions supporting auditory and cognitive processing. The purpose of this study was to determine whether there is a systematic association between hearing ability and brain volume in cross-sectional data from a large nonclinical cohort of middle-aged adults available from the UK Biobank Resource ( http://www.ukbiobank.ac.uk ). Method We performed a set of regression analyses to determine the association between speech reception threshold in noise (SRTn) and global brain volume as well as predefined regions of interest (ROIs) based on T1-weighted structural images, controlling for hearing-related comorbidities and cognition as well as demographic factors. In a 2nd set of analyses, we additionally controlled for hearing aid (HA) use. We predicted statistically significant associations globally and in ROIs including auditory and cognitive processing regions, possibly modulated by HA use. Results Whole-brain gray matter volume was significantly lower for individuals with poorer SRTn. Furthermore, the volume of 9 predicted ROIs including both auditory and cognitive processing regions was lower for individuals with poorer SRTn. The greatest percentage difference (-0.57%) in ROI volume relating to a 1 SD worsening of SRTn was found in the left superior temporal gyrus. HA use did not substantially modulate the pattern of association between brain volume and SRTn. Conclusions In a large middle-aged nonclinical population, poorer hearing ability is associated with lower brain volume globally as well as in cortical and subcortical regions involved in auditory and cognitive processing, but there was no conclusive evidence that this effect is moderated by HA use. This pattern of results supports the notion that poor hearing leads to reduced volume in brain regions recruited during speech understanding under challenging conditions. These findings should be tested in future longitudinal, experimental studies. Supplemental Material https://doi.org/10.23641/asha.7949357.
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Affiliation(s)
- Mary Rudner
- Linnaeus Centre HEAD, Department of Behavioural Sciences and Learning, Linköping University, Sweden
| | - Mark Seeto
- National Acoustic Laboratories and the HEARing CRC, Sydney, New South Wales, Australia
| | - Gitte Keidser
- National Acoustic Laboratories and the HEARing CRC, Sydney, New South Wales, Australia
| | - Blake Johnson
- Department of Cognitive Science, Macquarie University, Sydney, New South Wales, Australia
| | - Jerker Rönnberg
- Linnaeus Centre HEAD, Department of Behavioural Sciences and Learning, Linköping University, Sweden
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23
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Xu XM, Jiao Y, Tang TY, Zhang J, Salvi R, Teng GJ. Inefficient Involvement of Insula in Sensorineural Hearing Loss. Front Neurosci 2019; 13:133. [PMID: 30842724 PMCID: PMC6391342 DOI: 10.3389/fnins.2019.00133] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 02/06/2019] [Indexed: 01/22/2023] Open
Abstract
The insular cortex plays an important role in multimodal sensory processing, audio-visual integration and emotion; however, little is known about how the insula is affected by auditory deprivation due to sensorineural hearing loss (SNHL). To address this issue, we used structural and functional magnetic resonance imaging to determine if the neural activity within the insula and its interregional functional connectivity (FC) was disrupted by SNHL and if these alterations were correlated clinical measures of emotion and cognition. Thirty-five SNHL subjects and 54 Controls enrolled in our study underwent auditory evaluation, neuropsychological assessments, functional and structure MRI, respectively. Twenty five patients and 20 Controls underwent arterial spin labeling scanning. FC of six insula subdivisions were assessed and the FC results were compared to the neuropsychological tests. Interregional connections were also compared among insula-associated networks, including salience network (SN), default mode network (DMN), and central executive network (CEN). Compared to Controls, SNHL subjects demonstrated hyperperfusion in the insula and significantly decreased FC between some insula subdivisions and other brain regions, including thalamus, putamen, precentral gyrus, postcentral gyrus, mid-cingulate cortex, dorsolateral prefrontal cortex, rolandic operculum. Anxiety, depression and cognitive impairments were correlated with FC values. Abnormal interactions among SN, DMN, and CEN were observed in SNHL group. Our result provides support for the "inefficient high-order control" theory of the insula in which the auditory deprivation caused by SNHL contributes to impaired sensory integration and central deficits in emotional and cognitive processing.
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Affiliation(s)
- Xiao-Min Xu
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Yun Jiao
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Tian-Yu Tang
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Jian Zhang
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, United States
| | - Gao-Jun Teng
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
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24
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Williamson RS, Polley DB. Parallel pathways for sound processing and functional connectivity among layer 5 and 6 auditory corticofugal neurons. eLife 2019; 8:e42974. [PMID: 30735128 PMCID: PMC6384027 DOI: 10.7554/elife.42974] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 02/06/2019] [Indexed: 11/27/2022] Open
Abstract
Cortical layers (L) 5 and 6 are populated by intermingled cell-types with distinct inputs and downstream targets. Here, we made optogenetically guided recordings from L5 corticofugal (CF) and L6 corticothalamic (CT) neurons in the auditory cortex of awake mice to discern differences in sensory processing and underlying patterns of functional connectivity. Whereas L5 CF neurons showed broad stimulus selectivity with sluggish response latencies and extended temporal non-linearities, L6 CTs exhibited sparse selectivity and rapid temporal processing. L5 CF spikes lagged behind neighboring units and imposed weak feedforward excitation within the local column. By contrast, L6 CT spikes drove robust and sustained activity, particularly in local fast-spiking interneurons. Our findings underscore a duality among sub-cortical projection neurons, where L5 CF units are canonical broadcast neurons that integrate sensory inputs for transmission to distributed downstream targets, while L6 CT neurons are positioned to regulate thalamocortical response gain and selectivity.
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Affiliation(s)
- Ross S Williamson
- Eaton-Peabody LaboratoriesMassachusetts Eye and Ear InfirmaryBostonUnited States
- Department of OtolaryngologyHarvard Medical SchoolBostonUnited States
| | - Daniel B Polley
- Eaton-Peabody LaboratoriesMassachusetts Eye and Ear InfirmaryBostonUnited States
- Department of OtolaryngologyHarvard Medical SchoolBostonUnited States
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25
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Clarke BA, Lee CC. Inhibitory Projections in the Mouse Auditory Tectothalamic System. Brain Sci 2018; 8:E103. [PMID: 29890716 PMCID: PMC6025108 DOI: 10.3390/brainsci8060103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 05/30/2018] [Accepted: 06/07/2018] [Indexed: 12/24/2022] Open
Abstract
The medial geniculate body (MGB) is the target of excitatory and inhibitory inputs from several neural sources. Among these, the inferior colliculus (IC) is an important nucleus in the midbrain that acts as a nexus for auditory projections, ascending and descending, throughout the rest of the central auditory system and provides both excitatory and inhibitory inputs to the MGB. In our study, we assessed the relative contribution from presumed excitatory and inhibitory IC neurons to the MGB in mice. Using retrograde tract tracing with cholera toxin beta subunit (CTβ)-Alexa Fluor 594 injected into the MGB of transgenic, vesicular GABA transporter (VGAT)-Venus mice, we quantitatively analyzed the projections from both the ipsilateral and contralateral IC to the MGB. Our results demonstrate inhibitory projections from both ICs to the MGB that likely play a significant role in shaping auditory processing. These results complement prior studies in other species, which suggest that the inhibitory tectothalamic pathway is important in the regulation of neuronal activity in the auditory forebrain.
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Affiliation(s)
- Blaise A Clarke
- Department of Comparative Biomedical Sciences, LSU School of Veterinary Medicine, Baton Rouge, LA 70803, USA.
| | - Charles C Lee
- Department of Comparative Biomedical Sciences, LSU School of Veterinary Medicine, Baton Rouge, LA 70803, USA.
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Distinct Anatomical Connectivity Patterns Differentiate Subdivisions of the Nonlemniscal Auditory Thalamus in Mice. Cereb Cortex 2018; 29:2437-2454. [DOI: 10.1093/cercor/bhy115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 05/04/2018] [Indexed: 11/14/2022] Open
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Kamali A, Riascos RF, Pillai JJ, Sair HI, Patel R, Nelson FM, Lincoln JA, Tandon N, Mirbagheri S, Rabiei P, Keser Z, Hasan KM. Mapping the trajectory of the amygdalothalamic tract in the human brain. J Neurosci Res 2018; 96:1176-1185. [PMID: 29607550 DOI: 10.1002/jnr.24235] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 03/01/2018] [Accepted: 03/02/2018] [Indexed: 11/11/2022]
Abstract
Although the thalamus is not considered primarily as a limbic structure, abundant evidence indicates the essential role of the thalamus as a modulator of limbic functions indirectly through the amygdala. The amygdala is a central component of the limbic system and serves an essential role in modulating the core processes including the memory, decision-making, and emotional reactions. The amygdalothalamic pathway is the largest direct amygdalo-diencephalic connection in the primates including the human brain. Given the crucial role of the amygdalothalamic tract (ATT) in memory function and diencephalic amnesia in stroke patients, diffusion tensor imaging may be helpful in better visualizing the surgical anatomy of this pathway noninvasively. To date, few diffusion-weighted studies have focused on the amygdala, yet the fine neuronal connection of the amygdala and thalamus known as the ATT has yet to be elucidated. This study aimed to investigate the utility of high spatial resolution diffusion tensor tractography for mapping the trajectory of the ATT in the human brain. We studied 15 healthy right-handed human subjects (12 men and 3 women with age range of 24-37 years old). Using a high-resolution diffusion tensor tractography technique, for the first time, we were able to reconstruct and measure the trajectory of the ATT. We further revealed the close relationship of the ATT with the temporopontine tract and the fornix bilaterally in 15 healthy adult human brains.
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Affiliation(s)
- Arash Kamali
- Departments of Diagnostic Radiology, University of Texas at Houston, Houston, Texas, USA
| | - Roy F Riascos
- Departments of Diagnostic Radiology, University of Texas at Houston, Houston, Texas, USA
| | - Jay J Pillai
- Department of Diagnostic Radiology, Division of Neuroradiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Haris I Sair
- Department of Diagnostic Radiology, Division of Neuroradiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Rajan Patel
- Departments of Diagnostic Radiology, University of Texas at Houston, Houston, Texas, USA
| | - Flavia M Nelson
- Department of Neurology, University of Texas at Houston, Houston, Texas, USA
| | - John A Lincoln
- Department of Neurology, University of Texas at Houston, Houston, Texas, USA
| | - Nitin Tandon
- Department of Neurosurgery, University of Texas at Houston, Houston, Texas, USA
| | - Saeedeh Mirbagheri
- Department of Diagnostic Radiology, Mount Saini Beth Israel, New York, New York, USA
| | - Pejman Rabiei
- Departments of Diagnostic Radiology, University of Texas at Houston, Houston, Texas, USA
| | - Zafer Keser
- Department of Neurology, University of Texas at Houston, Houston, Texas, USA
| | - Khader M Hasan
- Departments of Diagnostic Radiology, University of Texas at Houston, Houston, Texas, USA
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28
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Baird A, Robinson GA. Novel cognitive insights from the first year after bi-thalamic infarct. Neurocase 2018; 24:76-81. [PMID: 29493434 DOI: 10.1080/13554794.2018.1444779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Neuropsychological consequences of bi-thalamic damage are scarcely known. This case study documents cognitive (in particular memory and executive) functioning in a man with a medial bi-thalamic infarct in the first year (8 and 12 months) post injury. NG showed persistent memory (including autobiographical) impairment, but improved executive functions at one year post injury. On a response inhibition task his speed of response improved but his ability to inhibit a "prepotent" automatic response declined, corresponding to an increase in behavioral disinhibition. Despite this, he showed intact performances on several social cognition tasks. This case contributes to our understanding of the role of the thalamus in mediating retrograde memory, executive, and social cognition functions.
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Affiliation(s)
- Amee Baird
- a Department of Psychology , Macquarie University , Sydney , Australia.,b Australian Research Council Centre of Excellence in Cognition and its Disorders , Macquarie University , Sydney , Australia
| | - Gail A Robinson
- c Neuropsychology Research Unit, School of Psychology , The University of Queensland , Brisbane , Australia
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29
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Scott BH, Saleem KS, Kikuchi Y, Fukushima M, Mishkin M, Saunders RC. Thalamic connections of the core auditory cortex and rostral supratemporal plane in the macaque monkey. J Comp Neurol 2017; 525:3488-3513. [PMID: 28685822 DOI: 10.1002/cne.24283] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 06/29/2017] [Accepted: 06/30/2017] [Indexed: 01/06/2023]
Abstract
In the primate auditory cortex, information flows serially in the mediolateral dimension from core, to belt, to parabelt. In the caudorostral dimension, stepwise serial projections convey information through the primary, rostral, and rostrotemporal (AI, R, and RT) core areas on the supratemporal plane, continuing to the rostrotemporal polar area (RTp) and adjacent auditory-related areas of the rostral superior temporal gyrus (STGr) and temporal pole. In addition to this cascade of corticocortical connections, the auditory cortex receives parallel thalamocortical projections from the medial geniculate nucleus (MGN). Previous studies have examined the projections from MGN to auditory cortex, but most have focused on the caudal core areas AI and R. In this study, we investigated the full extent of connections between MGN and AI, R, RT, RTp, and STGr using retrograde and anterograde anatomical tracers. Both AI and R received nearly 90% of their thalamic inputs from the ventral subdivision of the MGN (MGv; the primary/lemniscal auditory pathway). By contrast, RT received only ∼45% from MGv, and an equal share from the dorsal subdivision (MGd). Area RTp received ∼25% of its inputs from MGv, but received additional inputs from multisensory areas outside the MGN (30% in RTp vs. 1-5% in core areas). The MGN input to RTp distinguished this rostral extension of auditory cortex from the adjacent auditory-related cortex of the STGr, which received 80% of its thalamic input from multisensory nuclei (primarily medial pulvinar). Anterograde tracers identified complementary descending connections by which highly processed auditory information may modulate thalamocortical inputs.
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Affiliation(s)
- Brian H Scott
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health (NIMH/NIH), Bethesda, Maryland
| | - Kadharbatcha S Saleem
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health (NIMH/NIH), Bethesda, Maryland
| | - Yukiko Kikuchi
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health (NIMH/NIH), Bethesda, Maryland
| | - Makoto Fukushima
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health (NIMH/NIH), Bethesda, Maryland
| | - Mortimer Mishkin
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health (NIMH/NIH), Bethesda, Maryland
| | - Richard C Saunders
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health (NIMH/NIH), Bethesda, Maryland
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Distinct Neural Properties in the Low-Frequency Region of the Chicken Cochlear Nucleus Magnocellularis. eNeuro 2017; 4:eN-NWR-0016-17. [PMID: 28413822 PMCID: PMC5388668 DOI: 10.1523/eneuro.0016-17.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 02/17/2017] [Accepted: 03/05/2017] [Indexed: 12/03/2022] Open
Abstract
Topography in the avian cochlear nucleus magnocellularis (NM) is represented as gradually increasing characteristic frequency (CF) along the caudolateral-to-rostromedial axis. In this study, we characterized the organization and cell biophysics of the caudolateral NM (NMc) in chickens (Gallus gallus). Examination of cellular and dendritic architecture first revealed that NMc contains small neurons and extensive dendritic processes, in contrast to adendritic, large neurons located more rostromedially. Individual dye-filling study further demonstrated that NMc is divided into two subregions, with NMc2 neurons having larger and more complex dendritic fields than NMc1. Axonal tract tracing studies confirmed that NMc1 and NMc2 neurons receive afferent inputs from the auditory nerve and the superior olivary nucleus, similar to the adendritic NM. However, the auditory axons synapse with NMc neurons via small bouton-like terminals, unlike the large end bulb synapses on adendritic NM neurons. Immunocytochemistry demonstrated that most NMc2 neurons express cholecystokinin but not calretinin, distinct from NMc1 and adendritic NM neurons that are cholecystokinin negative and mostly calretinin positive. Finally, whole-cell current clamp recordings revealed that NMc neurons require significantly lower threshold current for action potential generation than adendritic NM neurons. Moreover, in contrast to adendritic NM neurons that generate a single-onset action potential, NMc neurons generate multiple action potentials to suprathreshold sustained depolarization. Taken together, our data indicate that NMc contains multiple neuron types that are structurally, connectively, molecularly, and physiologically different from traditionally defined NM neurons, emphasizing specialized neural properties for processing low-frequency sounds.
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Márquez-Legorreta E, Horta-Júnior JDAC, Berrebi AS, Saldaña E. Organization of the Zone of Transition between the Pretectum and the Thalamus, with Emphasis on the Pretectothalamic Lamina. Front Neuroanat 2016; 10:82. [PMID: 27563286 PMCID: PMC4980397 DOI: 10.3389/fnana.2016.00082] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 07/25/2016] [Indexed: 12/23/2022] Open
Abstract
The zone of transition between the pretectum, derived from prosomere 1, and the thalamus, derived from prosomere 2, is structurally complex and its understanding has been hampered by cytoarchitectural and terminological confusion. Herein, using a battery of complementary morphological approaches, including cytoarchitecture, myeloarchitecture and the expression of molecular markers, we pinpoint the features or combination of features that best characterize each nucleus of the pretectothalamic transitional zone of the rat. Our results reveal useful morphological criteria to identify and delineate, with unprecedented precision, several [mostly auditory] nuclei of the posterior group of the thalamus, namely the pretectothalamic lamina (PTL; formerly known as the posterior limitans nucleus), the medial division of the medial geniculate body (MGBm), the suprageniculate nucleus (SG), and the ethmoid, posterior triangular and posterior nuclei of the thalamus. The PTL is a sparsely-celled and fiber rich flattened nucleus apposed to the lateral surface of the anterior pretectal nucleus (APT) that marks the border between the pretectum and the thalamus; this structure stains selectively with the Wisteria floribunda agglutinin (WFA), and is essentially immunonegative for the calcium binding protein parvalbumin (PV). The MGBm, located medial to the ventral division of the MGB (MGBv), can be unequivocally identified by the large size of many of its neurons, its dark immunostaining for PV, and its rather selective staining for WFA. The SG, which extends for a considerable caudorostral distance and deviates progressively from the MGB, is characterized by its peculiar cytoarchitecture, the paucity of myelinated fibers, and the conspicuous absence of staining for calretinin (CR); indeed, in many CR-stained sections, the SG stands out as a blank spot. Because most of these nuclei are small and show unique anatomical relationships, the information provided in this article will facilitate the interpretation of the results of experimental manipulations aimed at the auditory thalamus and improve the design of future investigations. Moreover, the previously neglected proximity between the MGBm and the caudal region of the scarcely known PTL raises the possibility that certain features or roles traditionally attributed to the MGBm may actually belong to the PTL.
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Affiliation(s)
- Emmanuel Márquez-Legorreta
- Neuroscience Institute of Castilla y León (INCyL), University of SalamancaSalamanca, Spain; Department of Cell Biology and Pathology, Medical School, University of SalamancaSalamanca, Spain
| | | | - Albert S Berrebi
- Department of Otolaryngology-Head and Neck Surgery and the Sensory Neuroscience Research Center, West Virginia University Morgantown, WV, USA
| | - Enrique Saldaña
- Neuroscience Institute of Castilla y León (INCyL), University of SalamancaSalamanca, Spain; Department of Cell Biology and Pathology, Medical School, University of SalamancaSalamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University of SalamancaSalamanca, Spain
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Wisteria Floribunda Agglutinin-Labeled Perineuronal Nets in the Mouse Inferior Colliculus, Thalamic Reticular Nucleus and Auditory Cortex. Brain Sci 2016; 6:brainsci6020013. [PMID: 27089371 PMCID: PMC4931490 DOI: 10.3390/brainsci6020013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 03/25/2016] [Accepted: 04/06/2016] [Indexed: 01/24/2023] Open
Abstract
Perineuronal nets (PNNs) are specialized extracellular matrix molecules that are associated with the closing of the critical period, among other functions. In the adult brain, PNNs surround specific types of neurons, however the expression of PNNs in the auditory system of the mouse, particularly at the level of the midbrain and forebrain, has not been fully described. In addition, the association of PNNs with excitatory and inhibitory cell types in these structures remains unknown. Therefore, we sought to investigate the expression of PNNs in the inferior colliculus (IC), thalamic reticular nucleus (TRN) and primary auditory cortex (A1) of the mouse brain by labeling with wisteria floribunda agglutinin (WFA). To aid in the identification of inhibitory neurons in these structures, we employed the vesicular GABA transporter (VGAT)-Venus transgenic mouse strain, which robustly expresses an enhanced yellow-fluorescent protein (Venus) natively in nearly all gamma-amino butyric acid (GABA)-ergic inhibitory neurons, thus enabling a rapid and unambiguous assessment of inhibitory neurons throughout the nervous system. Our results demonstrate that PNNs are expressed throughout the auditory midbrain and forebrain, but vary in their local distribution. PNNs are most dense in the TRN and least dense in A1. Furthermore, PNNs are preferentially associated with inhibitory neurons in A1 and the TRN, but not in the IC of the mouse. These data suggest regionally specific roles for PNNs in auditory information processing.
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