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Mitelut C, Diez Castro M, Peterson RE, Goncalves M, Li J, Gamer MM, Nilsson SRO, Pereira TD, Sanes DH. A behavioral roadmap for the development of agency in the rodent. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.10.566632. [PMID: 38014127 PMCID: PMC10680634 DOI: 10.1101/2023.11.10.566632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Behavioral interactions within the nuclear family play a pivotal role in the emergence of agency: the capacity to regulate physiological, psychological and social needs. While behaviors may develop over days or weeks in line with nervous system maturation, individual behaviors can occur on sub-second time scales making it challenging to track development in lab studies with brief observation periods, or in field studies with limited temporal precision and animal identification. Here we study development in families of gerbils, a highly social rodent, collecting tens of millions of behavior time points and implementing machine learning methods to track individual subjects. We provided maturing gerbils with a large, undisturbed environment between postnatal day 15 and the age at which they would typically disperse from the family unit (day 30). We identified complex and distinct developmental trajectories for food and water acquisition, solitary exploration, and social behaviors, some of which displayed sex differences and diurnal patterns. Our work supports the emergence of well-delineated autonomous and social behavior phenotypes that correlate with specific periods and loci of neural maturation.
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Zadrozny M, Drapich P, Gasiorowska-Bien A, Niewiadomski W, Harrington CR, Wischik CM, Riedel G, Niewiadomska G. Neuroprotection of Cholinergic Neurons with a Tau Aggregation Inhibitor and Rivastigmine in an Alzheimer's-like Tauopathy Mouse Model. Cells 2024; 13:642. [PMID: 38607082 PMCID: PMC11011792 DOI: 10.3390/cells13070642] [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: 02/27/2024] [Revised: 03/21/2024] [Accepted: 04/04/2024] [Indexed: 04/13/2024] Open
Abstract
Basal forebrain cholinergic dysfunction, most likely linked with tau protein aggregation, is a characteristic feature of Alzheimer's disease (AD). Recent evidence suggests that tau protein is a putative target for the treatment of dementia, and the tau aggregation inhibitor, hydromethylthionine mesylate (HMTM), has emerged as a potential disease-modifying treatment. However, its efficacy was diminished in patients already receiving approved acetylcholinesterase inhibitors. In this study, we ask whether this negative interaction can also be mimicked in experimental tau models of AD and whether the underlying mechanism can be understood. From a previous age profiling study, 6-month-old line 1 (L1) tau transgenic mice were characterized by a severe reduction in several cholinergic markers. We therefore assessed whether long-term pre-exposure with the acetylcholinesterase inhibitor rivastigmine alone and in conjunction with the tau aggregation inhibitor HMTM can reverse cholinergic deficits in L1. Rivastigmine and HMTM, and combinations of the two compounds were administered orally for 11 weeks to both L1 and wild-type mice. The brains were sectioned with a focus on the basal forebrain, motor cortex and hippocampus. Immunohistochemical staining and quantification of choline acetyltransferase (ChAT), tyrosine kinase A (TrkA)-positive neurons and relative optical intensity (ROI) for vesicular acetylcholine transporter (VAChT), and acetylcholinesterase (AChE) reactivity confirmed reversal of the diminished cholinergic phenotype of interneurons (nucleus accumbens, striatum) and projection neurons (medial septum, nucleus basalis magnocellularis) by HMTM, to a greater extent than by rivastigmine alone in L1 mice. Combined administration did not yield additivity but, in most proxies, led to antagonistic effects in which rivastigmine decreased the benefits shown with HMTM alone. Local markers (VAChT and AChE) in target structures of the basal forebrain, motor cortex and hippocampal CA3 seemed to be normalized by HMTM, but not by rivastigmine or the combination of both drugs. HMTM, which was developed as a tau aggregation inhibitor, strongly decreased the tau load in L1 mice, however, not in combination with rivastigmine. Taken together, these data confirm a cholinergic phenotype in L1 tau transgenic mice that resembles the deficits observed in AD patients. This phenotype is reversible by HMTM, but at the same time appears to be subject to a homeostatic regulation induced by chronic pre-treatment with an acetylcholinesterase inhibitor, which interferes with the efficacy of HMTM. The strongest phenotypic reversal coincided with a normalization of the tau load in the cortex and hippocampus of L1, suggesting that tau accumulation underpins the loss of cholinergic markers in the basal forebrain and its projection targets.
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Affiliation(s)
- Maciej Zadrozny
- Mossakowski Medical Research Institute, 02-106 Warsaw, Poland; (M.Z.); (P.D.); (A.G.-B.); (W.N.)
| | - Patrycja Drapich
- Mossakowski Medical Research Institute, 02-106 Warsaw, Poland; (M.Z.); (P.D.); (A.G.-B.); (W.N.)
| | - Anna Gasiorowska-Bien
- Mossakowski Medical Research Institute, 02-106 Warsaw, Poland; (M.Z.); (P.D.); (A.G.-B.); (W.N.)
| | - Wiktor Niewiadomski
- Mossakowski Medical Research Institute, 02-106 Warsaw, Poland; (M.Z.); (P.D.); (A.G.-B.); (W.N.)
| | - Charles R. Harrington
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen AB25 2ZD, UK; (C.R.H.); (C.M.W.); (G.R.)
- TauRx Therapeutics Ltd., Aberdeen AB24 3FX, UK
| | - Claude M. Wischik
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen AB25 2ZD, UK; (C.R.H.); (C.M.W.); (G.R.)
- TauRx Therapeutics Ltd., Aberdeen AB24 3FX, UK
| | - Gernot Riedel
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen AB25 2ZD, UK; (C.R.H.); (C.M.W.); (G.R.)
| | - Grazyna Niewiadomska
- Mossakowski Medical Research Institute, 02-106 Warsaw, Poland; (M.Z.); (P.D.); (A.G.-B.); (W.N.)
- Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
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Murlanova K, Pletnikov MV. Modeling psychotic disorders: Environment x environment interaction. Neurosci Biobehav Rev 2023; 152:105310. [PMID: 37437753 DOI: 10.1016/j.neubiorev.2023.105310] [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] [Received: 12/14/2022] [Revised: 06/26/2023] [Accepted: 07/05/2023] [Indexed: 07/14/2023]
Abstract
Schizophrenia is a major psychotic disorder with multifactorial etiology that includes interactions between genetic vulnerability and environmental risk factors. In addition, interplay of multiple environmental adversities affects neurodevelopment and may increase the individual risk of developing schizophrenia. Consistent with the two-hit hypothesis of schizophrenia, we review rodent models that combine maternal immune activation as the first hit with other adverse environmental exposures as the second hit. We discuss the strengths and pitfalls of the current animal models of environment x environment interplay and propose some future directions to advance the field.
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Affiliation(s)
- Kateryna Murlanova
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Mikhail V Pletnikov
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Hollis E, Li Y. Nicotinic acetylcholine signaling is required for motor learning but not for rehabilitation from spinal cord injury. Neural Regen Res 2023; 18:364-367. [PMID: 35900431 PMCID: PMC9396487 DOI: 10.4103/1673-5374.346544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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5
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Bowles S, Hickman J, Peng X, Williamson WR, Huang R, Washington K, Donegan D, Welle CG. Vagus nerve stimulation drives selective circuit modulation through cholinergic reinforcement. Neuron 2022; 110:2867-2885.e7. [PMID: 35858623 DOI: 10.1016/j.neuron.2022.06.017] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 04/22/2022] [Accepted: 06/17/2022] [Indexed: 12/23/2022]
Abstract
Vagus nerve stimulation (VNS) is a neuromodulation therapy for a broad and expanding set of neurologic conditions. However, the mechanism through which VNS influences central nervous system circuitry is not well described, limiting therapeutic optimization. VNS leads to widespread brain activation, but the effects on behavior are remarkably specific, indicating plasticity unique to behaviorally engaged neural circuits. To understand how VNS can lead to specific circuit modulation, we leveraged genetic tools including optogenetics and in vivo calcium imaging in mice learning a skilled reach task. We find that VNS enhances skilled motor learning in healthy animals via a cholinergic reinforcement mechanism, producing a rapid consolidation of an expert reach trajectory. In primary motor cortex (M1), VNS drives precise temporal modulation of neurons that respond to behavioral outcome. This suggests that VNS may accelerate motor refinement in M1 via cholinergic signaling, opening new avenues for optimizing VNS to target specific disease-relevant circuitry.
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Affiliation(s)
- Spencer Bowles
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO 80045, USA; Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Jordan Hickman
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Xiaoyu Peng
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO 80045, USA; Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - W Ryan Williamson
- IDEA Core, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Rongchen Huang
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO 80045, USA; Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Kayden Washington
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO 80045, USA; Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Dane Donegan
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO 80045, USA; Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Cristin G Welle
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO 80045, USA; Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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Li Y, Hollis E. Basal Forebrain Cholinergic Neurons Selectively Drive Coordinated Motor Learning in Mice. J Neurosci 2021; 41:10148-10160. [PMID: 34750228 PMCID: PMC8660044 DOI: 10.1523/jneurosci.1152-21.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 10/27/2021] [Accepted: 10/29/2021] [Indexed: 11/21/2022] Open
Abstract
Motor control requires precise temporal and spatial encoding across distinct motor centers that is refined through the repetition of learning. The recruitment of motor regions requires modulatory input to shape circuit activity. Here, we identify a role for the baso-cortical cholinergic pathway in the acquisition of a coordinated motor skill in mice. Targeted depletion of basal forebrain cholinergic neurons results in significant impairments in training on the rotarod task of coordinated movement. Cholinergic neuromodulation is required during training sessions as chemogenetic inactivation of cholinergic neurons also impairs task acquisition. Rotarod learning is known to drive refinement of corticostriatal neurons arising in both medial prefrontal cortex (mPFC) and motor cortex, and we have found that cholinergic input to both motor regions is required for task acquisition. Critically, the effects of cholinergic neuromodulation are restricted to the acquisition stage, as depletion of basal forebrain cholinergic neurons after learning does not affect task execution. Our results indicate a critical role for cholinergic neuromodulation of distant cortical motor centers during coordinated motor learning.SIGNIFICANCE STATEMENT Acetylcholine release from basal forebrain cholinergic neuron terminals rapidly modulates neuronal excitability, circuit dynamics, and cortical coding; all processes required for processing complex sensory information, cognition, and attention. We found that depletion or transient silencing of cholinergic inputs to anatomically isolated motor areas, medial prefrontal cortex (mPFC) and motor cortex, selectively led to significant impairments on coordinated motor learning; disrupting this baso-cortical network after acquisition elicited no effect on task execution. Our results indicate a pivotal role for cholinergic neuromodulation of distant cortical motor centers during coordinated motor learning. These findings support the concept that cognitive components (such as attention) are indispensable in the adjustment of motor output and training-induced improvements in motor performance.
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Affiliation(s)
- Yue Li
- Burke Neurological Institute, White Plains, New York 10605
| | - Edmund Hollis
- Burke Neurological Institute, White Plains, New York 10605
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065
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7
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Wolf VL, Ergul A. Progress and challenges in preclinical stroke recovery research. Brain Circ 2021; 7:230-240. [PMID: 35071838 PMCID: PMC8757504 DOI: 10.4103/bc.bc_33_21] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/16/2021] [Accepted: 10/22/2021] [Indexed: 01/29/2023] Open
Abstract
Significant innovations in the management of acute ischemic stroke have led to an increased incidence in the long-term complications of stroke. Therefore, there is an urgent need for improvements in and refinement of rehabilitation interventions that can lead to functional and neuropsychological recovery. The goal of this review is to summarize the current progress and challenges involved with preclinical stroke recovery research. Moving forward, stroke recovery research should be placing an increased emphasis on the incorporation of comorbid diseases and biological variables in preclinical models in order to overcome translational roadblocks to establishing successful clinical rehabilitation interventions.
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Affiliation(s)
- Victoria Lea Wolf
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina, USA
| | - Adviye Ergul
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina, USA
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8
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Chen R, Goldberg JH. Actor-critic reinforcement learning in the songbird. Curr Opin Neurobiol 2020; 65:1-9. [PMID: 32898752 PMCID: PMC7769887 DOI: 10.1016/j.conb.2020.08.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 11/18/2022]
Abstract
It feels rewarding to ace your opponent on match point. Here, we propose common mechanisms underlie reward and performance learning. First, when a singing bird unexpectedly hits the right note, its dopamine (DA) neurons are activated as when a thirsty monkey receives an unexpected juice reward. Second, these DA signals reinforce vocal variations much as they reinforce stimulus-response associations. Third, limbic inputs to DA neurons signal the predicted quality of song syllables much like they signal the predicted reward value of a place or a stimulus during foraging. Finally, songbirds may solve difficult problems in reinforcement learning - such as credit assignment and catastrophic forgetting - with node perturbation and consolidation of reinforced vocal patterns in motor cortical circuits. Consolidation occurs downstream of a canonical 'actor-critic' circuit motif that learns to maximize performance quality in essentially the same way it learns to maximize reward: by computing and learning from prediction errors.
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Affiliation(s)
- Ruidong Chen
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, United States
| | - Jesse H Goldberg
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, United States.
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9
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Latchoumane CFV, Barany DA, Karumbaiah L, Singh T. Neurostimulation and Reach-to-Grasp Function Recovery Following Acquired Brain Injury: Insight From Pre-clinical Rodent Models and Human Applications. Front Neurol 2020; 11:835. [PMID: 32849253 PMCID: PMC7396659 DOI: 10.3389/fneur.2020.00835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/06/2020] [Indexed: 12/26/2022] Open
Abstract
Reach-to-grasp is an evolutionarily conserved motor function that is adversely impacted following stroke and traumatic brain injury (TBI). Non-invasive brain stimulation (NIBS) methods, such as transcranial magnetic stimulation and transcranial direct current stimulation, are promising tools that could enhance functional recovery of reach-to-grasp post-brain injury. Though the rodent literature provides a causal understanding of post-injury recovery mechanisms, it has had a limited impact on NIBS protocols in human research. The high degree of homology in reach-to-grasp circuitry between humans and rodents further implies that the application of NIBS to brain injury could be better informed by findings from pre-clinical rodent models and neurorehabilitation research. Here, we provide an overview of the advantages and limitations of using rodent models to advance our current understanding of human reach-to-grasp function, cortical circuitry, and reorganization. We propose that a cross-species comparison of reach-to-grasp recovery could provide a mechanistic framework for clinically efficacious NIBS treatments that could elicit better functional outcomes for patients.
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Affiliation(s)
- Charles-Francois V. Latchoumane
- Department of Animal and Dairy Science, University of Georgia, Athens, GA, United States
- Regenerative Bioscience Center, University of Georgia, Athens, GA, United States
| | - Deborah A. Barany
- Department of Kinesiology, University of Georgia, Athens, GA, United States
| | - Lohitash Karumbaiah
- Department of Animal and Dairy Science, University of Georgia, Athens, GA, United States
- Regenerative Bioscience Center, University of Georgia, Athens, GA, United States
| | - Tarkeshwar Singh
- Regenerative Bioscience Center, University of Georgia, Athens, GA, United States
- Department of Kinesiology, University of Georgia, Athens, GA, United States
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Hayashi M, Hinckley CA, Driscoll SP, Moore NJ, Levine AJ, Hilde KL, Sharma K, Pfaff SL. Graded Arrays of Spinal and Supraspinal V2a Interneuron Subtypes Underlie Forelimb and Hindlimb Motor Control. Neuron 2018; 97:869-884.e5. [PMID: 29398364 PMCID: PMC8601153 DOI: 10.1016/j.neuron.2018.01.023] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 12/04/2017] [Accepted: 01/10/2018] [Indexed: 01/13/2023]
Abstract
The spinal cord contains neural networks that enable regionally distinct motor outputs along the body axis. Nevertheless, it remains unclear how segment-specific motor computations are processed because the cardinal interneuron classes that control motor neurons appear uniform at each level of the spinal cord. V2a interneurons are essential to both forelimb and hindlimb movements, and here we identify two major types that emerge during development: type I neurons marked by high Chx10 form recurrent networks with neighboring spinal neurons and type II neurons that downregulate Chx10 and project to supraspinal structures. Types I and II V2a interneurons are arrayed in counter-gradients, and this network activates different patterns of motor output at cervical and lumbar levels. Single-cell RNA sequencing (RNA-seq) revealed type I and II V2a neurons are each comprised of multiple subtypes. Our findings uncover a molecular and anatomical organization of V2a interneurons reminiscent of the orderly way motor neurons are divided into columns and pools.
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Affiliation(s)
- Marito Hayashi
- Gene Expression Laboratory and the Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines, La Jolla, CA 92037, USA; Biological Sciences Graduate Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92037, USA
| | - Christopher A Hinckley
- Gene Expression Laboratory and the Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines, La Jolla, CA 92037, USA
| | - Shawn P Driscoll
- Gene Expression Laboratory and the Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines, La Jolla, CA 92037, USA
| | - Niall J Moore
- Gene Expression Laboratory and the Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines, La Jolla, CA 92037, USA
| | - Ariel J Levine
- Gene Expression Laboratory and the Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines, La Jolla, CA 92037, USA
| | - Kathryn L Hilde
- Gene Expression Laboratory and the Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines, La Jolla, CA 92037, USA
| | - Kamal Sharma
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 South Wood Street, Chicago, IL 60612, USA
| | - Samuel L Pfaff
- Gene Expression Laboratory and the Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines, La Jolla, CA 92037, USA.
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Vitrac C, Benoit-Marand M. Monoaminergic Modulation of Motor Cortex Function. Front Neural Circuits 2017; 11:72. [PMID: 29062274 PMCID: PMC5640772 DOI: 10.3389/fncir.2017.00072] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Accepted: 09/19/2017] [Indexed: 01/09/2023] Open
Abstract
Elaboration of appropriate responses to behavioral situations rests on the ability of selecting appropriate motor outcomes in accordance to specific environmental inputs. To this end, the primary motor cortex (M1) is a key structure for the control of voluntary movements and motor skills learning. Subcortical loops regulate the activity of the motor cortex and thus contribute to the selection of appropriate motor plans. Monoamines are key mediators of arousal, attention and motivation. Their firing pattern enables a direct encoding of different states thus promoting or repressing the selection of actions adapted to the behavioral context. Monoaminergic modulation of motor systems has been extensively studied in subcortical circuits. Despite evidence of converging projections of multiple neurotransmitters systems in the motor cortex pointing to a direct modulation of local circuits, their contribution to the execution and learning of motor skills is still poorly understood. Monoaminergic dysregulation leads to impaired plasticity and motor function in several neurological and psychiatric conditions, thus it is critical to better understand how monoamines modulate neural activity in the motor cortex. This review aims to provide an update of our current understanding on the monoaminergic modulation of the motor cortex with an emphasis on motor skill learning and execution under physiological conditions.
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Affiliation(s)
- Clément Vitrac
- Laboratoire de Neurosciences Expérimentales et Cliniques, INSERM U1084, Poitiers, France.,Laboratoire de Neurosciences Expérimentales et Cliniques, Université de Poitiers, Poitiers, France
| | - Marianne Benoit-Marand
- Laboratoire de Neurosciences Expérimentales et Cliniques, INSERM U1084, Poitiers, France.,Laboratoire de Neurosciences Expérimentales et Cliniques, Université de Poitiers, Poitiers, France
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12
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Baumann VJ, Koch U. Perinatal nicotine exposure impairs the maturation of glutamatergic inputs in the auditory brainstem. J Physiol 2017; 595:3573-3590. [PMID: 28190266 DOI: 10.1113/jp274059] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 01/25/2017] [Indexed: 01/11/2023] Open
Abstract
KEY POINTS Chronic perinatal nicotine exposure causes abnormal auditory brainstem responses and auditory processing deficits in children and animal models. The effect of perinatal nicotine exposure on synaptic maturation in the auditory brainstem was investigated in granule cells in the ventral nucleus of the lateral lemniscus, which receive a single calyx-like input from the cochlear nucleus. Perinatal nicotine exposure caused a massive reduction in the amplitude of the excitatory input current. This caused a profound decrease in the number and temporal precision of spikes in these neurons. Perinatal nicotine exposure delayed the developmental downregulation of functional nicotinic acetylcholine receptors on these neurons. ABSTRACT Maternal smoking causes chronic nicotine exposure during early development and results in auditory processing deficits including delayed speech development and learning difficulties. Using a mouse model of chronic, perinatal nicotine exposure we explored to what extent synaptic inputs to granule cells in the ventral nucleus of the lateral lemniscus are affected by developmental nicotine treatment. These neurons receive one large calyx-like input from octopus cells in the cochlear nucleus and play a role in sound pattern analysis, including speech sounds. In addition, they exhibit high levels of α7 nicotinic acetylcholine receptors, especially during early development. Our whole-cell patch-clamp experiments show that perinatal nicotine exposure causes a profound reduction in synaptic input amplitude. In contrast, the number of inputs innervating each neuron and synaptic release properties of this calyx-like synapse remained unaltered. Spike number and spiking precision in response to synaptic stimulation were greatly diminished, especially for later stimuli during a stimulus train. Moreover, chronic nicotine exposure delayed the developmental downregulation of functional nicotinic acetylcholine receptors on these neurons, indicating a direct action of nicotine in this brain area. This presumably direct effect of perinatal nicotine exposure on synaptic maturation in the auditory brainstem might be one of the underlying causes for auditory processing difficulties in children of heavy smoking mothers.
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Affiliation(s)
- Veronika J Baumann
- Institute of Biology, Neurophysiology, Freie Universität Berlin, 14195, Berlin, Germany
| | - Ursula Koch
- Institute of Biology, Neurophysiology, Freie Universität Berlin, 14195, Berlin, Germany.,NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117, Berlin, Germany
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13
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Serradj N, Agger SF, Hollis ER. Corticospinal circuit plasticity in motor rehabilitation from spinal cord injury. Neurosci Lett 2016; 652:94-104. [PMID: 27939980 DOI: 10.1016/j.neulet.2016.12.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 11/29/2016] [Accepted: 12/02/2016] [Indexed: 11/18/2022]
Abstract
Restoring corticospinal function after spinal cord injury is a significant challenge as the corticospinal tract elicits no substantive, spontaneous regeneration, and its interruption leaves a permanent deficit. The corticospinal circuit serves multiple motor and sensory functions within the mammalian nervous system as the direct link between isocortex and spinal cord. Maturation of the corticospinal circuit involves the refinement of projections within the spinal cord and a subsequent refinement of motor maps within the cortex. The plasticity of these cortical motor maps mirrors the acquisition of skilled motor learning, and both the maps and motor skills are disrupted following injury to the corticospinal tract. The motor cortex exhibits the capacity to incorporate changes in corticospinal projections induced by both spontaneous and therapeutic-mediated plasticity of corticospinal axons through appropriate rehabilitation. An understanding of the mechanisms of corticospinal plasticity in motor learning will undoubtedly help inform strategies to improve motor rehabilitation after spinal cord injury.
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Affiliation(s)
- Najet Serradj
- Burke Medical Research Institute, White Plains, New York, NY 10605, United States
| | - Sydney F Agger
- Burke Medical Research Institute, White Plains, New York, NY 10605, United States
| | - Edmund R Hollis
- Burke Medical Research Institute, White Plains, New York, NY 10605, United States; Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, United States.
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14
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