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Campbell PW, Govindaiah G, Guido W. Development of reciprocal connections between the dorsal lateral geniculate nucleus and the thalamic reticular nucleus. Neural Dev 2024; 19:6. [PMID: 38890758 PMCID: PMC11184795 DOI: 10.1186/s13064-024-00183-5] [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: 03/04/2024] [Accepted: 05/22/2024] [Indexed: 06/20/2024] Open
Abstract
The thalamic reticular nucleus (TRN) serves as an important node between the thalamus and neocortex, regulating thalamocortical rhythms and sensory processing in a state dependent manner. Disruptions in TRN circuitry also figures prominently in several neurodevelopmental disorders including epilepsy, autism, and attentional defects. An understanding of how and when connections between TRN and 1st order thalamic nuclei, such as the dorsal lateral geniculate nucleus (dLGN), develop is lacking. We used the mouse visual thalamus as a model system to study the organization, pattern of innervation and functional responses between TRN and the dLGN. Genetically modified mouse lines were used to visualize and target the feedforward and feedback components of these intra-thalamic circuits and to understand how peripheral input from the retina impacts their development.Retrograde tracing of thalamocortical (TC) afferents through TRN revealed that the modality-specific organization seen in the adult, is present at perinatal ages and seems impervious to the loss of peripheral input. To examine the formation and functional maturation of intrathalamic circuits between the visual sector of TRN and dLGN, we examined when projections from each nuclei arrive, and used an acute thalamic slice preparation along with optogenetic stimulation to assess the maturation of functional synaptic responses. Although thalamocortical projections passed through TRN at birth, feedforward axon collaterals determined by vGluT2 labeling, emerged during the second postnatal week, increasing in density through the third week. Optogenetic stimulation of TC axon collaterals in TRN showed infrequent, weak excitatory responses near the end of week 1. During weeks 2-4, responses became more prevalent, grew larger in amplitude and exhibited synaptic depression during repetitive stimulation. Feedback projections from visual TRN to dLGN began to innervate dLGN as early as postnatal day 2 with weak inhibitory responses emerging during week 1. During week 2-4, inhibitory responses continued to grow larger, showing synaptic depression during repetitive stimulation. During this time TRN inhibition started to suppress TC spiking, having its greatest impact by week 4-6. Using a mutant mouse that lacks retinofugal projections revealed that the absence of retinal input led to an acceleration of TRN innervation of dLGN but had little impact on the development of feedforward projections from dLGN to TRN. Together, these experiments reveal how and when intrathalamic connections emerge during early postnatal ages and provide foundational knowledge to understand the development of thalamocortical network dynamics as well as neurodevelopmental diseases that involve TRN circuitry.
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Affiliation(s)
- Peter W Campbell
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, 511 S. Floyd St., Louisville, KY, 40292, USA
- Division of Neurology and Developmental Neurosciences, Baylor College of Medicine, Houston, USA
| | - Gubbi Govindaiah
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, 511 S. Floyd St., Louisville, KY, 40292, USA
| | - William Guido
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, 511 S. Floyd St., Louisville, KY, 40292, USA.
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2
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Griffith EY, ElSayed M, Dura-Bernal S, Neymotin SA, Uhlrich DJ, Lytton WW, Zhu JJ. Mechanism of an Intrinsic Oscillation in Rat Geniculate Interneurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.06.597830. [PMID: 38895250 PMCID: PMC11185623 DOI: 10.1101/2024.06.06.597830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Depolarizing current injections produced a rhythmic bursting of action potentials - a bursting oscillation - in a set of local interneurons in the lateral geniculate nucleus (LGN) of rats. The current dynamics underlying this firing pattern have not been determined, though this cell type constitutes an important cellular component of thalamocortical circuitry, and contributes to both pathologic and non-pathologic brain states. We thus investigated the source of the bursting oscillation using pharmacological manipulations in LGN slices in vitro and in silico. 1. Selective blockade of calcium channel subtypes revealed that high-threshold calcium currentsI L andI P contributed strongly to the oscillation. 2. Increased extracellular K+ concentration (decreased K+currents) eliminated the oscillation. 3. Selective blockade of K+ channel subtypes demonstrated that the calcium-sensitive potassium current (I A H P ) was of primary importance. A morphologically simplified, multicompartment model of the thalamic interneuron characterized the oscillation as follows: 1. The low-threshold calcium currentI T provided the strong initial burst characteristic of the oscillation. 2. Alternating fluxes through high-threshold calcium channels andI A H P then provided the continuing oscillation's burst and interburst periods respectively. This interplay betweenI L andI A H P contrasts with the current dynamics underlying oscillations in thalamocortical and reticularis neurons, which primarily involveI T andI H , orI T andI A H P respectively. These findings thus point to a novel electrophysiological mechanism for generating intrinsic oscillations in a major thalamic cell type. Because local interneurons can sculpt the behavior of thalamocortical circuits, these results suggest new targets for the manipulation of ascending thalamocortical network activity.
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Affiliation(s)
- Erica Y Griffith
- Department of Neural and Behavioral Sciences, SUNY Downstate Health Sciences University, Brooklyn, NY
- Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY
| | - Mohamed ElSayed
- Department of Psychiatry, Geisel School of Medicine at Dartmouth, Hanover, NH
- Department of Biomedical Engineering, SUNY Downstate School of Graduate Studies, Brooklyn, NY
- Department of Psychiatry, New Hampshire Hospital, Concord, NH
| | - Salvador Dura-Bernal
- Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY
| | - Samuel A Neymotin
- Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY
- Department of Psychiatry, New York University School of Medicine, New York, NY
| | - Daniel J Uhlrich
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, USA
| | - William W Lytton
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY
- Department of Neurology, Kings County Hospital, Brooklyn, NY
| | - J Julius Zhu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA
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Schmidt AR, Placer HJ, Muhammad IM, Shephard R, Patrick RL, Saurborn T, Horstick EJ, Bergeron SA. Transcriptional control of visual neural circuit development by GS homeobox 1. PLoS Genet 2024; 20:e1011139. [PMID: 38669217 PMCID: PMC11051655 DOI: 10.1371/journal.pgen.1011139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 01/16/2024] [Indexed: 04/28/2024] Open
Abstract
As essential components of gene expression networks, transcription factors regulate neural circuit assembly. The homeobox transcription factor encoding gene, gs homeobox 1 (gsx1), is expressed in the developing visual system; however, no studies have examined its role in visual system formation. In zebrafish, retinal ganglion cell (RGC) axons that transmit visual information to the brain terminate in ten arborization fields (AFs) in the optic tectum (TeO), pretectum (Pr), and thalamus. Pretectal AFs (AF1-AF9) mediate distinct visual behaviors, yet we understand less about their development compared to AF10 in the TeO. Using gsx1 zebrafish mutants, immunohistochemistry, and transgenic lines, we observed that gsx1 is required for vesicular glutamate transporter, Tg(slc17a6b:DsRed), expression in the Pr, but not overall neuron number. gsx1 mutants have normal eye morphology, yet they exhibit impaired visual ability during prey capture. RGC axon volume in the gsx1 mutant Pr and TeO is reduced, and AF7 that is active during feeding is missing which is consistent with reduced hunting performance. Timed laser ablation of Tg(slc17a6b:DsRed)-positive cells reveals that they are necessary for AF7 formation. This work is the first to implicate gsx1 in establishing cell identity and functional neural circuits in the visual system.
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Affiliation(s)
- Alexandra R. Schmidt
- Department of Biology, West Virginia University, Morgantown, West Virgina, United States of America
| | - Haiden J. Placer
- Department of Biology, West Virginia University, Morgantown, West Virgina, United States of America
| | - Ishmael M. Muhammad
- Department of Biology, West Virginia University, Morgantown, West Virgina, United States of America
| | - Rebekah Shephard
- Department of Biology, West Virginia University, Morgantown, West Virgina, United States of America
| | - Regina L. Patrick
- Department of Biology, West Virginia University, Morgantown, West Virgina, United States of America
| | - Taylor Saurborn
- Department of Biology, West Virginia University, Morgantown, West Virgina, United States of America
| | - Eric J. Horstick
- Department of Biology, West Virginia University, Morgantown, West Virgina, United States of America
- Department of Neuroscience, West Virginia University, Morgantown, West Virgina, United States of America
| | - Sadie A. Bergeron
- Department of Biology, West Virginia University, Morgantown, West Virgina, United States of America
- Department of Neuroscience, West Virginia University, Morgantown, West Virgina, United States of America
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Van Hook MJ, McCool S. Nonuniform scaling of synaptic inhibition in the dorsolateral geniculate nucleus in a mouse model of glaucoma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.27.587036. [PMID: 38586044 PMCID: PMC10996666 DOI: 10.1101/2024.03.27.587036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Elevated intraocular pressure (IOP) triggers glaucoma by damaging the output neurons of the retina called retinal ganglion cells (RGCs). This leads to the loss of RGC signaling to visual centers of the brain such as the dorsolateral geniculate nucleus (dLGN), which is critical for processing and relaying information to the cortex for conscious vision. In response to altered levels of activity or synaptic input, neurons can homeostatically modulate postsynaptic neurotransmitter receptor numbers, allowing them to scale their synaptic responses to stabilize spike output. While prior work has indicated unaltered glutamate receptor properties in the glaucomatous dLGN, it is unknown whether glaucoma impacts dLGN inhibition. Here, using DBA/2J mice, which develop elevated IOP beginning at 6-7 months of age, we tested whether the strength of inhibitory synapses on dLGN thalamocortical relay neurons is altered in response to the disease state. We found an enhancement of feed-forward disynaptic inhibition arising from local interneurons along with increased amplitude of quantal inhibitory synaptic currents. A combination of immunofluorescence staining for the GABA A -α1 receptor subunit, peak-scaled nonstationary fluctuation analysis, and measures of homeostatic synaptic scaling indicated this was the result of an approximately 1.4-fold increase in GABA receptor number at post-synaptic inhibitory synapses, although several pieces of evidence strongly indicate a non-uniform scaling across inhibitory synapses within individual relay neurons. Together, these results indicate an increase in inhibitory synaptic strength in the glaucomatous dLGN, potentially pointing toward homeostatic compensation for disruptions in network and neuronal function triggered by increased IOP. Significance Statement Elevated eye pressure in glaucoma leads to loss of retinal outputs to the dorsolateral geniculate nucleus (dLGN), which is critical for relaying information to the cortex for conscious vision. Alterations in neuronal activity, as could arise from excitatory synapse loss, can trigger homeostatic adaptations to synaptic function that attempt to maintain activity within a meaningful dynamic range, although whether this occurs uniformly at all synapses within a given neuron or is a non-uniform process is debated. Here, using a mouse model of glaucoma, we show that dLGN inhibitory synapses undergo non-uniform upregulation due to addition of post-synaptic GABA receptors. This is likely to be a neuronal adaptation to glaucomatous pathology in an important sub-cortical visual center.
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Filipiak P, Sajitha TA, Shepherd TM, Clarke K, Goldman H, Placantonakis DG, Zhang J, Chan KC, Boada FE, Baete SH. Improved reconstruction of crossing fibers in the mouse optic pathways with orientation distribution function fingerprinting. Magn Reson Med 2024; 91:1075-1086. [PMID: 37927121 DOI: 10.1002/mrm.29911] [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: 05/03/2023] [Revised: 10/10/2023] [Accepted: 10/14/2023] [Indexed: 11/07/2023]
Abstract
PURPOSE The accuracy of diffusion MRI tractography reconstruction decreases in the white matter regions with crossing fibers. The optic pathways in rodents provide a challenging structure to test new diffusion tractography approaches because of the small crossing volume within the optic chiasm and the unbalanced 9:1 proportion between the contra- and ipsilateral neural projections from the retina to the lateral geniculate nucleus, respectively. METHODS Common approaches based on Orientation Distribution Function (ODF) peak finding or statistical inference were compared qualitatively and quantitatively to ODF Fingerprinting (ODF-FP) for reconstruction of crossing fibers within the optic chiasm using in vivo diffusion MRI (n = 18 $$ n=18 $$ healthy C57BL/6 mice). Manganese-Enhanced MRI (MEMRI) was obtained after intravitreal injection of manganese chloride and used as a reference standard for the optic pathway anatomy. RESULTS ODF-FP outperformed by over 100% all the tested methods in terms of the ratios between the contra- and ipsilateral segments of the reconstructed optic pathways as well as the spatial overlap between tractography and MEMRI. CONCLUSION In this challenging model system, ODF-Fingerprinting reduced uncertainty of diffusion tractography for complex structural formations of fiber bundles.
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Affiliation(s)
- Patryk Filipiak
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, NYU Langone Health, New York, New York, USA
| | | | - Timothy M Shepherd
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, NYU Langone Health, New York, New York, USA
| | - Kamri Clarke
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, NYU Langone Health, New York, New York, USA
| | - Hannah Goldman
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, NYU Langone Health, New York, New York, USA
| | - Dimitris G Placantonakis
- Department of Neurosurgery, Perlmutter Cancer Center, Neuroscience Institute, Kimmel Center for Stem Cell Biology, NYU Langone Health, New York, New York, USA
| | - Jiangyang Zhang
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, NYU Langone Health, New York, New York, USA
| | - Kevin C Chan
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, NYU Langone Health, New York, New York, USA
- Department of Ophthalmology, NYU Langone Health, New York, New York, USA
| | - Fernando E Boada
- Radiological Sciences Laboratory and Molecular Imaging Program at Stanford, Department of Radiology, Stanford University, Stanford, California, USA
| | - Steven H Baete
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, NYU Langone Health, New York, New York, USA
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Stebbins K, Somaiya RD, Sabbagh U, Liang Y, Su J, Fox MA. Retinal input is required for the maintenance of neuronal laminae in the ventral lateral geniculate nucleus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.12.575402. [PMID: 38293194 PMCID: PMC10827117 DOI: 10.1101/2024.01.12.575402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Retinal ganglion cell (RGC) axons provide direct input into several nuclei of the mouse visual thalamus, including the dorsal lateral geniculate nucleus (dLGN), which is important for classical image-forming vision, and the ventral lateral geniculate nucleus (vLGN), which is associated with non-image-forming vision. Through both activity- and morphogen-dependent mechanisms, retinal inputs play important roles in the development of dLGN, including the refinement of retinal projections, morphological development of thalamocortical relay cells (TRCs), the timing of corticogeniculate innervation, and the recruitment of inhibitory interneurons from progenitor zones. In contrast, little is known about the role of retinal inputs in the development of vLGN. Grossly, vLGN is divided into two domains, the retinorecipient external vLGN (vLGNe) and the non-retinorecipient internal vLGN (vLGNi). We previously found that vLGNe consists of transcriptionally distinct GABAergic subtypes that are distributed into at least four adjacent laminae. At present, it remains unclear whether retinal inputs influence the development of these cell-specific neuronal laminae in vLGNe. Here, we elucidated the developmental timeline for the formation and maintenance of these laminae in the mouse vLGNe and results indicate that these laminae are specified at or before birth, well before eye-opening and the emergence of experience-dependent visual activity. We observed that mutant mice without retinal inputs have a normal laminar distribution of GABAergic cells at birth; however, after the first week of postnatal development, these mutants exhibited a dramatic disruption in the laminar organization of inhibitory neurons and clear boundaries between vLGNe and vLGNi. Overall, our results show that while the formation of cell type-specific layers in vLGNe does not depend on RGC inputs, retinal signals are critical for their maintenance.
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Li Z, Peng B, Huang JJ, Zhang Y, Seo MB, Fang Q, Zhang GW, Zhang X, Zhang LI, Tao HW. Enhancement and contextual modulation of visuospatial processing by thalamocollicular projections from ventral lateral geniculate nucleus. Nat Commun 2023; 14:7278. [PMID: 37949869 PMCID: PMC10638288 DOI: 10.1038/s41467-023-43147-9] [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: 03/05/2023] [Accepted: 11/01/2023] [Indexed: 11/12/2023] Open
Abstract
In the mammalian visual system, the ventral lateral geniculate nucleus (vLGN) of the thalamus receives salient visual input from the retina and sends prominent GABAergic axons to the superior colliculus (SC). However, whether and how vLGN contributes to fundamental visual information processing remains largely unclear. Here, we report in mice that vLGN facilitates visually-guided approaching behavior mediated by the lateral SC and enhances the sensitivity of visual object detection. This can be attributed to the extremely broad spatial integration of vLGN neurons, as reflected in their much lower preferred spatial frequencies and broader spatial receptive fields than SC neurons. Through GABAergic thalamocollicular projections, vLGN specifically exerts prominent surround suppression of visuospatial processing in SC, leading to a fine tuning of SC preferences to higher spatial frequencies and smaller objects in a context-dependent manner. Thus, as an essential component of the central visual processing pathway, vLGN serves to refine and contextually modulate visuospatial processing in SC-mediated visuomotor behaviors via visually-driven long-range feedforward inhibition.
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Affiliation(s)
- Zhong Li
- Center for Neural Circuits and Sensory Processing Disorders, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Bo Peng
- Center for Neural Circuits and Sensory Processing Disorders, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
- Graduate Program in Neuroscience, University of Southern California, Los Angeles, CA, 90033, USA
| | - Junxiang J Huang
- Center for Neural Circuits and Sensory Processing Disorders, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
- Graduate Program in Biological and Biomedical Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Yuan Zhang
- Center for Neural Circuits and Sensory Processing Disorders, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Michelle B Seo
- Center for Neural Circuits and Sensory Processing Disorders, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
- Graduate Program in Neuroscience, University of Southern California, Los Angeles, CA, 90033, USA
| | - Qi Fang
- Center for Neural Circuits and Sensory Processing Disorders, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
- Graduate Program in Neuroscience, University of Southern California, Los Angeles, CA, 90033, USA
| | - Guang-Wei Zhang
- Center for Neural Circuits and Sensory Processing Disorders, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Xiaohui Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Li I Zhang
- Center for Neural Circuits and Sensory Processing Disorders, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
| | - Huizhong Whit Tao
- Center for Neural Circuits and Sensory Processing Disorders, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
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Brown TC, Crouse EC, Attaway CA, Oakes DK, Minton SW, Borghuis BG, McGee AW. Microglia are dispensable for experience-dependent refinement of visual circuitry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.17.562708. [PMID: 37905138 PMCID: PMC10614920 DOI: 10.1101/2023.10.17.562708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Microglia are proposed to be critical for the refinement of developing neural circuitry. However, evidence identifying specific roles for microglia has been limited and often indirect. Here we examined whether microglia are required for the experience-dependent refinement of visual circuitry and visual function during development. We ablated microglia by administering the colony-stimulating factor 1 receptor (CSF1R) inhibitor PLX5622, and then examined the consequences for retinal function, receptive field tuning of neurons in primary visual cortex (V1), visual acuity, and experience-dependent plasticity in visual circuitry. Eradicating microglia by treating mice with PLX5622 beginning at postnatal day (P) 14 did not alter visual response properties of retinal ganglion cells examined three or more weeks later. Mice treated with PLX5622 from P14 lacked more than 95% of microglia in V1 by P18, prior to the opening of the critical period. Despite the absence of microglia, the receptive field tuning properties of neurons in V1 were normal at P32. Similarly, eradicating microglia did not affect the maturation of visual acuity. Mice treated with PLX5622 displayed typical ocular dominance plasticity in response to brief monocular deprivation. Thus, none of these principal measurements of visual circuit development and function detectibly differed in the absence of microglia. We conclude that microglia are dispensable for experience-dependent refinement of visual circuitry. These findings challenge the proposed critical role of microglia in refining neural circuitry.
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Affiliation(s)
- Thomas C. Brown
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Emily C. Crouse
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Cecilia A. Attaway
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Dana K. Oakes
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Sarah W. Minton
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Bart G. Borghuis
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
| | - Aaron W. McGee
- Department of Anatomical Sciences and Neurobiology, School of Medicine; University of Louisville, Louisville, KY, 40202
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Gao J, Lu Y, Luo Y, Duan X, Chen P, Zhang X, Wu X, Qiu M, Shen W. β-Catenin and SOX2 Interaction Regulate Visual Experience-Dependent Cell Homeostasis in the Developing Xenopus Thalamus. Int J Mol Sci 2023; 24:13593. [PMID: 37686400 PMCID: PMC10488257 DOI: 10.3390/ijms241713593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/19/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023] Open
Abstract
In the vertebrate brain, sensory experience plays a crucial role in shaping thalamocortical connections for visual processing. However, it is still not clear how visual experience influences tissue homeostasis and neurogenesis in the developing thalamus. Here, we reported that the majority of SOX2-positive cells in the thalamus are differentiated neurons that receive visual inputs as early as stage 47 Xenopus. Visual deprivation (VD) for 2 days shifts the neurogenic balance toward proliferation at the expense of differentiation, which is accompanied by a reduction in nuclear-accumulated β-catenin in SOX2-positive neurons. The knockdown of β-catenin decreases the expression of SOX2 and increases the number of progenitor cells. Coimmunoprecipitation studies reveal the evolutionary conservation of strong interactions between β-catenin and SOX2. These findings indicate that β-catenin interacts with SOX2 to maintain homeostatic neurogenesis during thalamus development.
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Affiliation(s)
- Juanmei Gao
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
- College of Life and Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yufang Lu
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Yuhao Luo
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Xinyi Duan
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Peiyao Chen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Xinyu Zhang
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Xiaohua Wu
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
| | - Mengsheng Qiu
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
- College of Life and Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wanhua Shen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China (M.Q.)
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10
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Tikidji-Hamburyan RA, Govindaiah G, Guido W, Colonnese MT. Synaptic and circuit mechanisms prevent detrimentally precise correlation in the developing mammalian visual system. eLife 2023; 12:e84333. [PMID: 37211984 PMCID: PMC10202458 DOI: 10.7554/elife.84333] [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: 10/20/2022] [Accepted: 04/25/2023] [Indexed: 05/23/2023] Open
Abstract
The developing visual thalamus and cortex extract positional information encoded in the correlated activity of retinal ganglion cells by synaptic plasticity, allowing for the refinement of connectivity. Here, we use a biophysical model of the visual thalamus during the initial visual circuit refinement period to explore the role of synaptic and circuit properties in the regulation of such neural correlations. We find that the NMDA receptor dominance, combined with weak recurrent excitation and inhibition characteristic of this age, prevents the emergence of spike-correlations between thalamocortical neurons on the millisecond timescale. Such precise correlations, which would emerge due to the broad, unrefined connections from the retina to the thalamus, reduce the spatial information contained by thalamic spikes, and therefore we term them 'parasitic' correlations. Our results suggest that developing synapses and circuits evolved mechanisms to compensate for such detrimental parasitic correlations arising from the unrefined and immature circuit.
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Affiliation(s)
| | - Gubbi Govindaiah
- Department of Anatomical Sciences and Neurobiology, University of LouisvilleLouisvilleUnited States
| | - William Guido
- Department of Anatomical Sciences and Neurobiology, University of LouisvilleLouisvilleUnited States
| | - Matthew T Colonnese
- Department of Pharmacology and Physiology, The George Washington UniversityWashingtonUnited States
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Shin D, Peelman K, Lien AD, Del Rosario J, Haider B. Narrowband gamma oscillations propagate and synchronize throughout the mouse thalamocortical visual system. Neuron 2023; 111:1076-1085.e8. [PMID: 37023711 PMCID: PMC10112544 DOI: 10.1016/j.neuron.2023.03.006] [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: 05/02/2022] [Revised: 12/16/2022] [Accepted: 03/06/2023] [Indexed: 04/08/2023]
Abstract
Oscillations of neural activity permeate sensory systems. In the visual system, broadband gamma oscillations (30-80 Hz) are thought to act as a communication mechanism underlying perception. However, these oscillations show widely varying frequency and phase, providing constraints for coordinating spike timing across areas. Here, we examined Allen Brain Observatory data and performed causal experiments to show that narrowband gamma (NBG) oscillations (50-70 Hz) propagate and synchronize throughout the awake mouse visual system. Lateral geniculate nucleus (LGN) neurons fired precisely relative to NBG phase in primary visual cortex (V1) and multiple higher visual areas (HVAs). NBG neurons across areas showed a higher likelihood of functional connectivity and stronger visual responses; remarkably, NBG neurons in LGN, preferring bright (ON) versus dark (OFF), fired at distinct NBG phases aligned across the cortical hierarchy. NBG oscillations may thus serve to coordinate spike timing across brain areas and facilitate communication of distinct visual features during perception.
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Affiliation(s)
- Donghoon Shin
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA; Electrical and Computer Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA; Bioengineering, UCSF - UC Berkeley Joint PhD Program, San Francisco, CA, USA
| | - Kayla Peelman
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Anthony D Lien
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Joseph Del Rosario
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Bilal Haider
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA.
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12
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Maher EE, Briegel AC, Imtiaz S, Fox MA, Golino H, Erisir A. 3D electron microscopy and volume-based bouton sorting reveal the selectivity of inputs onto geniculate relay cell and interneuron dendrite segments. Front Neuroanat 2023; 17:1150747. [PMID: 37007643 PMCID: PMC10064015 DOI: 10.3389/fnana.2023.1150747] [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: 01/24/2023] [Accepted: 02/27/2023] [Indexed: 03/19/2023] Open
Abstract
Introduction The visual signals evoked at the retinal ganglion cells are modified and modulated by various synaptic inputs that impinge on lateral geniculate nucleus cells before they are sent to the cortex. The selectivity of geniculate inputs for clustering or forming microcircuits on discrete dendritic segments of geniculate cell types may provide the structural basis for network properties of the geniculate circuitry and differential signal processing through the parallel pathways of vision. In our study, we aimed to reveal the patterns of input selectivity on morphologically discernable relay cell types and interneurons in the mouse lateral geniculate nucleus. Methods We used two sets of Scanning Blockface Electron Microscopy (SBEM) image stacks and Reconstruct software to manually reconstruct of terminal boutons and dendrite segments. First, using an unbiased terminal sampling (UTS) approach and statistical modeling, we identified the criteria for volume-based sorting of geniculate boutons into their putative origins. Geniculate terminal boutons that were sorted in retinal and non-retinal categories based on previously described mitochondrial morphology, could further be sorted into multiple subpopulations based on their bouton volume distributions. Terminals deemed non-retinal based on the morphological criteria consisted of five distinct subpopulations, including small-sized putative corticothalamic and cholinergic boutons, two medium-sized putative GABAergic inputs, and a large-sized bouton type that contains dark mitochondria. Retinal terminals also consisted of four distinct subpopulations. The cutoff criteria for these subpopulations were then applied to datasets of terminals that synapse on reconstructed dendrite segments of relay cells or interneurons. Results Using a network analysis approach, we found an almost complete segregation of retinal and cortical terminals on putative X-type cell dendrite segments characterized by grape-like appendages and triads. On these cells, interneuron appendages intermingle with retinal and other medium size terminals to form triads within glomeruli. In contrast, a second, presumed Y-type cell displayed dendrodendritic puncta adherentia and received all terminal types without a selectivity for synapse location; these were not engaged in triads. Furthermore, the contribution of retinal and cortical synapses received by X-, Y- and interneuron dendrites differed such that over 60% of inputs to interneuron dendrites were from the retina, as opposed to 20% and 7% to X- and Y-type cells, respectively. Conclusion The results underlie differences in network properties of synaptic inputs from distinct origins on geniculate cell types.
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Affiliation(s)
- Erin E Maher
- Department of Psychology, University of Virginia, Charlottesville, VA, United States
| | - Alex C Briegel
- Department of Psychology, University of Virginia, Charlottesville, VA, United States
| | - Shahrozia Imtiaz
- Department of Psychology, University of Virginia, Charlottesville, VA, United States
| | - Michael A Fox
- School of Neuroscience, Virginia Tech, Blacksburg, VA, United States
- Fralin Biomedical Research Institute, Roanoke, VA, United States
| | - Hudson Golino
- Department of Psychology, University of Virginia, Charlottesville, VA, United States
| | - Alev Erisir
- Department of Psychology, University of Virginia, Charlottesville, VA, United States
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13
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Zhang C, Yadav S, Speer CM. The synaptic basis of activity-dependent eye-specific competition. Cell Rep 2023; 42:112085. [PMID: 36753422 PMCID: PMC10404640 DOI: 10.1016/j.celrep.2023.112085] [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: 05/31/2022] [Revised: 12/23/2022] [Accepted: 01/24/2023] [Indexed: 02/09/2023] Open
Abstract
Binocular vision requires proper developmental wiring of eye-specific inputs to the brain. In the thalamus, axons from the two eyes initially overlap in the dorsal lateral geniculate nucleus and undergo activity-dependent competition to segregate into target domains. Here, we combine eye-specific tract tracing with volumetric super-resolution imaging to measure the nanoscale molecular reorganization of developing retinogeniculate eye-specific synapses in the mouse brain. We show there are eye-specific differences in presynaptic vesicle pool size and vesicle association with the active zone at the earliest stages of retinogeniculate refinement but find no evidence of eye-specific differences in subsynaptic domain number, size, or transsynaptic alignment across development. Genetic disruption of spontaneous retinal activity decreases retinogeniculate synapse density, delays the emergence eye-specific differences in vesicle organization, and disrupts subsynaptic domain maturation. These results suggest that activity-dependent eye-specific presynaptic maturation underlies synaptic competition in the mammalian visual system.
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Affiliation(s)
- Chenghang Zhang
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Swapnil Yadav
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Colenso M Speer
- Department of Biology, University of Maryland, College Park, MD 20742, USA.
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14
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Santana NNM, Silva EHA, dos Santos SF, Costa MSMO, Nascimento Junior ES, Engelberth RCJG, Cavalcante JS. Retinorecipient areas in the common marmoset ( Callithrix jacchus): An image-forming and non-image forming circuitry. Front Neural Circuits 2023; 17:1088686. [PMID: 36817647 PMCID: PMC9932520 DOI: 10.3389/fncir.2023.1088686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 01/10/2023] [Indexed: 02/05/2023] Open
Abstract
The mammalian retina captures a multitude of diverse features from the external environment and conveys them via the optic nerve to a myriad of retinorecipient nuclei. Understanding how retinal signals act in distinct brain functions is one of the most central and established goals of neuroscience. Using the common marmoset (Callithrix jacchus), a monkey from Northeastern Brazil, as an animal model for parsing how retinal innervation works in the brain, started decades ago due to their marmoset's small bodies, rapid reproduction rate, and brain features. In the course of that research, a large amount of new and sophisticated neuroanatomical techniques was developed and employed to explain retinal connectivity. As a consequence, image and non-image-forming regions, functions, and pathways, as well as retinal cell types were described. Image-forming circuits give rise directly to vision, while the non-image-forming territories support circadian physiological processes, although part of their functional significance is uncertain. Here, we reviewed the current state of knowledge concerning retinal circuitry in marmosets from neuroanatomical investigations. We have also highlighted the aspects of marmoset retinal circuitry that remain obscure, in addition, to identify what further research is needed to better understand the connections and functions of retinorecipient structures.
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Affiliation(s)
- Nelyane Nayara M. Santana
- Laboratory of Neurochemical Studies, Department of Physiology and Behavior, Bioscience Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Eryck H. A. Silva
- Laboratory of Neurochemical Studies, Department of Physiology and Behavior, Bioscience Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Sâmarah F. dos Santos
- Laboratory of Neurochemical Studies, Department of Physiology and Behavior, Bioscience Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Miriam S. M. O. Costa
- Laboratory of Neuroanatomy, Department of Morphology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Expedito S. Nascimento Junior
- Laboratory of Neuroanatomy, Department of Morphology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Rovena Clara J. G. Engelberth
- Laboratory of Neurochemical Studies, Department of Physiology and Behavior, Bioscience Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Jeferson S. Cavalcante
- Laboratory of Neurochemical Studies, Department of Physiology and Behavior, Bioscience Center, Federal University of Rio Grande do Norte, Natal, Brazil,*Correspondence: Jeferson S. Cavalcante,
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15
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Min KW, Kim N, Lee JH, Sung Y, Kim M, Lee EJ, Kim JM, Kim JH, Lee J, Cho W, Yang JM, Kim N, Kim J, Lee CJ, Park YG, Lee SH, Lee HW, Kim JW. Visuomotor anomalies in achiasmatic mice expressing a transfer-defective Vax1 mutant. Exp Mol Med 2023; 55:385-400. [PMID: 36737666 PMCID: PMC9981622 DOI: 10.1038/s12276-023-00930-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 11/21/2022] [Accepted: 11/23/2022] [Indexed: 02/05/2023] Open
Abstract
In binocular animals that exhibit stereoscopic visual responses, the axons of retinal ganglion cells (RGCs) connect to brain areas bilaterally by forming a commissure called the optic chiasm (OC). Ventral anterior homeobox 1 (Vax1) contributes to the formation of the OC, acting endogenously in optic pathway cells and exogenously in growing RGC axons. Here, we generated Vax1AA/AA mice expressing the Vax1AA mutant, which is incapable of intercellular transfer. We found that RGC axons cannot take up Vax1AA protein from the Vax1AA/AA mouse optic stalk (OS) and grow slowly to arrive at the hypothalamus at a late stage. The RGC axons of Vax1AA/AA mice connect exclusively to ipsilateral brain areas after failing to access the midline, resulting in reduced visual acuity and abnormal oculomotor responses. Overall, our study provides physiological evidence for the necessity of intercellular transfer of Vax1 and the importance of the bilateral RGC axon projection in proper visuomotor responses.
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Affiliation(s)
- Kwang Wook Min
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Namsuk Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea.,Neurovascular Unit, Korea Brain Research Institute, Daegu, 41062, Republic of Korea
| | - Jae Hoon Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Younghoon Sung
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Museong Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Eun Jung Lee
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Jong-Myeong Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Jae-Hyun Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Jaeyoung Lee
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Wonjin Cho
- Department of Bio & Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Jee Myung Yang
- Department of Ophthalmology, Dongguk University Ilsan Hospital, Dongguk-ro 27, Ilsandong-gu, Goyang, Gyeong-gi, Republic of Korea
| | - Nury Kim
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, 34126, Republic of Korea
| | - Jaehoon Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - C Justin Lee
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, 34126, Republic of Korea
| | - Young-Gyun Park
- Department of Bio & Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Seung-Hee Lee
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Han-Woong Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 03722, Republic of Korea
| | - Jin Woo Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea.
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16
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Moreno-Juan V, Aníbal-Martínez M, Herrero-Navarro Á, Valdeolmillos M, Martini FJ, López-Bendito G. Spontaneous Thalamic Activity Modulates the Cortical Innervation of the Primary Visual Nucleus of the Thalamus. Neuroscience 2023; 508:87-97. [PMID: 35878717 DOI: 10.1016/j.neuroscience.2022.07.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 01/17/2023]
Abstract
Sensory processing relies on the correct development of thalamocortical loops. Visual corticothalamic axons (CTAs) invade the dorsolateral geniculate nucleus (dLGN) of the thalamus in early postnatal mice according to a regulated program that includes activity-dependent mechanisms. Spontaneous retinal activity influences the thalamic incursion of CTAs, yet the perinatal thalamus also generates intrinsic patterns of spontaneous activity whose role in modulating afferent connectivity remains unknown. Here, we found that patterned spontaneous activity in the dLGN contributes to proper spatial and temporal innervation of CTAs. Disrupting patterned spontaneous activity in the dLGN delays corticogeniculate innervation under normal conditions and upon eye enucleation. The delayed innervation was evident throughout the first two postnatal weeks but resumes after eye-opening, suggesting that visual experience is necessary for the homeostatic recovery of corticogeniculate innervation.
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Affiliation(s)
- Verónica Moreno-Juan
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas (UMH-CSIC), Sant Joan d'Alacant, Spain
| | - Mar Aníbal-Martínez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas (UMH-CSIC), Sant Joan d'Alacant, Spain
| | - Álvaro Herrero-Navarro
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas (UMH-CSIC), Sant Joan d'Alacant, Spain
| | - Miguel Valdeolmillos
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas (UMH-CSIC), Sant Joan d'Alacant, Spain
| | - Francisco J Martini
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas (UMH-CSIC), Sant Joan d'Alacant, Spain.
| | - Guillermina López-Bendito
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas (UMH-CSIC), Sant Joan d'Alacant, Spain.
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17
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Loss of Retinogeniculate Synaptic Function in the DBA/2J Mouse Model of Glaucoma. eNeuro 2022; 9:ENEURO.0421-22.2022. [PMID: 36526366 PMCID: PMC9794376 DOI: 10.1523/eneuro.0421-22.2022] [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] [Received: 10/11/2022] [Revised: 11/22/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
Retinal ganglion cell (RGC) axons comprise the optic nerve and carry information to the dorsolateral geniculate nucleus (dLGN), which is then relayed to the cortex for conscious vision. Glaucoma is a blinding neurodegenerative disease that commonly results from intraocular pressure (IOP)-associated injury leading to RGC axonal pathology, disruption of RGC outputs to the brain, and eventual apoptotic loss of RGC somata. The consequences of elevated IOP and glaucomatous pathology on RGC signaling to the dLGN are largely unknown yet are likely to contribute to vision loss. Here, we used anatomic and physiological approaches to study the structure and function of retinogeniculate (RG) synapses in male and female DBA/2J (D2) mice with inherited glaucoma before and after IOP elevation. D2 mice showed progressive loss of anterograde optic tract transport to the dLGN and vGlut2 labeling of RGC axon terminals while patch-clamp measurements of RG synaptic function showed that synaptic transmission was reduced in 9-month and 12-month D2 mice because of the loss of individual RGC axon inputs. TC neuron dendrites had reduced Sholl complexity at 12 months, suggestive of delayed reorganization following reduced synaptic input. There was no detectable change in RGC density in 11- to 12-month D2 retinas, quantified as the number of ganglion cell layer-residing somata immuno-positive for NeuN and immuno-negative for the amacrine marker choline acetyltransferase (ChAT). Thus, observed synaptic defects appear to precede RGC somatic loss. These findings identify glaucoma-associated and IOP-associated deficits in an important subcortical RGC projection target, shedding light on processes linking IOP to vision loss.
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18
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Li N, Liu Q, Zhang Y, Yang Z, Shi X, Gu Y. Cortical feedback modulates distinct critical period development in mouse visual thalamus. iScience 2022; 26:105752. [PMID: 36590174 PMCID: PMC9794980 DOI: 10.1016/j.isci.2022.105752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/15/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022] Open
Abstract
In primary visual cortex (V1), critical period for ocular dominance (OD) plasticity is a well-defined developmental stage to shape neuronal circuits based on visual experience. Recent studies showed that V1-like OD plasticity existed in mouse dorsal lateral geniculate nucleus (dLGN). It is still unclear what the exact time window is and how neural circuits contribute to OD plasticity in dLGN. Using in vivo electrophysiology, we defined a critical period for OD plasticity in dLGN from eye opening to puberty. There also existed an innate process of OD formation from contralateral to equal bias in dLGN binocular neurons. Instant V1 inactivation with muscimol had no effect on OD bias or plasticity. Short-term V1 inactivation with N-methyl-d-aspartate reversed the formation of equal OD bias, while long-term V1 inactivation retained dLGN development to an immature stage.
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Affiliation(s)
- Na Li
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Qiong Liu
- School of Life Sciences, Westlake University, Hangzhou 310000, China
| | - Yimu Zhang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Zhongyi Yang
- School of Basic Medicine, Fudan University, Shanghai 200032, China
| | - Xuefeng Shi
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300020, China
- Institute of Ophthalmology, Nankai University, Tianjin 300020, China
- Corresponding author
| | - Yu Gu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
- Corresponding author
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19
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Somaiya RD, Stebbins K, Gingrich EC, Xie H, Campbell JN, Garcia ADR, Fox MA. Sonic hedgehog-dependent recruitment of GABAergic interneurons into the developing visual thalamus. eLife 2022; 11:e79833. [PMID: 36342840 PMCID: PMC9640189 DOI: 10.7554/elife.79833] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 10/10/2022] [Indexed: 11/09/2022] Open
Abstract
Axons of retinal ganglion cells (RGCs) play critical roles in the development of inhibitory circuits in visual thalamus. We previously reported that RGC axons signal astrocytes to induce the expression of fibroblast growth factor 15 (FGF15), a motogen required for GABAergic interneuron migration into visual thalamus. However, how retinal axons induce thalamic astrocytes to generate Fgf15 and influence interneuron migration remains unknown. Here, we demonstrate that impairing RGC activity had little impact on interneuron recruitment into mouse visual thalamus. Instead, our data show that retinal-derived sonic hedgehog (SHH) is essential for interneuron recruitment. Specifically, we show that thalamus-projecting RGCs express SHH and thalamic astrocytes generate downstream components of SHH signaling. Deletion of RGC-derived SHH leads to a significant decrease in Fgf15 expression, as well as in the percentage of interneurons recruited into visual thalamus. Overall, our findings identify a morphogen-dependent neuron-astrocyte signaling mechanism essential for the migration of thalamic interneurons.
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Affiliation(s)
- Rachana Deven Somaiya
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech CarilionRoanokeUnited States
- Graduate Program in Translational Biology, Medicine, and Health, Virginia TechBlacksburgUnited States
| | - Katelyn Stebbins
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech CarilionRoanokeUnited States
- Graduate Program in Translational Biology, Medicine, and Health, Virginia TechBlacksburgUnited States
- Virginia Tech Carilion School of MedicineRoanokeUnited States
| | - Ellen C Gingrich
- Department of Biology, Drexel UniversityPhiladelphiaUnited States
- Department of Neurobiology and Anatomy, Drexel University College of MedicinePhiladelphiaUnited States
| | - Hehuang Xie
- Fralin Life Sciences Institute at Virginia TechBlacksburgUnited States
- School of Neuroscience, College of Science, Virginia TechBlacksburgUnited States
- Genetics, Bioinformatics and Computational Biology Program, Virginia TechBlacksburgUnited States
- Department of Biomedical Sciences and Pathobiology, Virginia–Maryland College of Veterinary MedicineBlacksburgUnited States
| | - John N Campbell
- Department of Biology, University of VirginiaCharlottesvilleUnited States
- Neuroscience Graduate Program, University of VirginiaCharlottesvilleUnited States
| | - A Denise R Garcia
- Department of Biology, Drexel UniversityPhiladelphiaUnited States
- Department of Neurobiology and Anatomy, Drexel University College of MedicinePhiladelphiaUnited States
| | - Michael A Fox
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech CarilionRoanokeUnited States
- School of Neuroscience, College of Science, Virginia TechBlacksburgUnited States
- Department of Biological Sciences, College of Science, Virginia TechBlacksburgUnited States
- Department of Pediatrics, Virginia Tech Carilion School of MedicineRoanokeUnited States
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20
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Van Hook MJ. Brain-derived neurotrophic factor is a regulator of synaptic transmission in the adult visual thalamus. J Neurophysiol 2022; 128:1267-1277. [PMID: 36224192 PMCID: PMC9662800 DOI: 10.1152/jn.00540.2021] [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: 12/16/2021] [Revised: 10/12/2022] [Accepted: 10/12/2022] [Indexed: 11/22/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is an important regulator of circuit development, neuronal survival, and plasticity throughout the nervous system. In the visual system, BDNF is produced by retinal ganglion cells (RGCs) and transported along their axons to central targets. Within the dorsolateral geniculate nucleus (dLGN), a key RGC projection target for conscious vision, the BDNF receptor tropomyosin receptor kinase B (TrkB) is present on RGC axon terminals and postsynaptic thalamocortical (TC) relay neuron dendrites. Based on this, the goal of this study was to determine how BDNF modulates the conveyance of signals through the retinogeniculate (RG) pathway of adult mice. Application of BDNF to dLGN brain slices increased TC neuron spiking evoked by optogenetic stimulation of RGC axons. There was a modest contribution to this effect from a BDNF-dependent enhancement of TC neuron intrinsic excitability including increased input resistance and membrane depolarization. BDNF also increased evoked vesicle release from RGC axon terminals, as evidenced by increased amplitude of evoked excitatory postsynaptic currents (EPSCs), which was blocked by inhibition of TrkB or phospholipase C. High-frequency stimulation revealed that BDNF increased synaptic vesicle pool size, release probability, and replenishment rate. There was no effect of BDNF on EPSC amplitude or short-term plasticity of corticothalamic feedback synapses. Thus, BDNF regulates RG synapses by both presynaptic and postsynaptic mechanisms. These findings suggest that BNDF influences the flow of visual information through the retinogeniculate pathway.NEW & NOTEWORTHY Brain-derived neurotrophic factor (BDNF) is an important regulator of neuronal development and plasticity. In the visual system, BDNF is transported along retinal ganglion cell (RGC) axons to the dorsolateral geniculate nucleus (dLGN), although it is not known how it influences mature dLGN function. Here, BDNF enhanced thalamocortical relay neuron responses to signals arising from RGC axons in the dLGN, pointing toward an important role for BDNF in processing signals en route to the visual cortex.
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Affiliation(s)
- Matthew J Van Hook
- Truhlsen Eye Institute, Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
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21
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Guidance landscapes unveiled by quantitative proteomics to control reinnervation in adult visual system. Nat Commun 2022; 13:6040. [PMID: 36229455 PMCID: PMC9561644 DOI: 10.1038/s41467-022-33799-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 09/30/2022] [Indexed: 12/24/2022] Open
Abstract
In the injured adult central nervous system (CNS), activation of pro-growth molecular pathways in neurons leads to long-distance regeneration. However, most regenerative fibers display guidance defects, which prevent reinnervation and functional recovery. Therefore, the molecular characterization of the proper target regions of regenerative axons is essential to uncover the modalities of adult reinnervation. In this study, we use mass spectrometry (MS)-based quantitative proteomics to address the proteomes of major nuclei of the adult visual system. These analyses reveal that guidance-associated molecules are expressed in adult visual targets. Moreover, we show that bilateral optic nerve injury modulates the expression of specific proteins. In contrast, the expression of guidance molecules remains steady. Finally, we show that regenerative axons are able to respond to guidance cues ex vivo, suggesting that these molecules possibly interfere with brain target reinnervation in adult. Using a long-distance regeneration model, we further demonstrate that the silencing of specific guidance signaling leads to rerouting of regenerative axons in vivo. Altogether, our results suggest ways to modulate axon guidance of regenerative neurons to achieve circuit repair in adult.
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22
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Van Hook MJ. Influences of Glaucoma on the Structure and Function of Synapses in the Visual System. Antioxid Redox Signal 2022; 37:842-861. [PMID: 35044228 PMCID: PMC9587776 DOI: 10.1089/ars.2021.0253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 12/31/2021] [Indexed: 11/12/2022]
Abstract
Significance: Glaucoma is an age-related neurodegenerative disorder of the visual system associated with sensitivity to intraocular pressure (IOP). It is the leading irreversible cause of vision loss worldwide, and vision loss results from damage and dysfunction of the retinal output neurons known as retinal ganglion cells (RGCs). Recent Advances: Elevated IOP and optic nerve injury triggers pruning of RGC dendrites, altered morphology of excitatory inputs from presynaptic bipolar cells, and disrupted RGC synaptic function. Less is known about RGC outputs, although evidence to date indicates that glaucoma is associated with altered mitochondrial and synaptic structure and function in RGC-projection targets in the brain. These early functional changes likely contribute to vision loss and might be a window into early diagnosis and treatment. Critical Issues: Glaucoma affects different RGC populations to varying extents and along distinct time courses. The influence of glaucoma on RGC synaptic function as well as the mechanisms underlying these effects remain to be determined. Since RGCs are an especially energetically demanding population of neurons, altered intracellular axon transport of mitochondria and mitochondrial function might contribute to RGC synaptic dysfunction in the retina and brain as well as RGC vulnerability in glaucoma. Future Directions: The mechanisms underlying differential RGC vulnerability remain to be determined. Moreover, the timing and mechanisms of RGCs synaptic dysfunction and degeneration will provide valuable insight into the disease process in glaucoma. Future work will be able to capitalize on these findings to better design diagnostic and therapeutic approaches to detect disease and prevent vision loss. Antioxid. Redox Signal. 37, 842-861.
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Affiliation(s)
- Matthew J. Van Hook
- Department of Ophthalmology & Visual Science and Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Department of Cellular & Integrative Physiology, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Hetsch F, Wang D, Chen X, Zhang J, Aslam M, Kegel M, Tonner H, Grus F, von Engelhardt J. CKAMP44 controls synaptic function and strength of relay neurons during early development of the dLGN. J Physiol 2022; 600:3549-3565. [PMID: 35770953 DOI: 10.1113/jp283172] [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: 04/06/2022] [Accepted: 06/27/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Expression of CKAMP44 starts early during development of the dLGN and remains stable in relay neurons and interneurons. Genetic deletion of CKAMP44 decreases synaptic strength and increases silent synapse number in dLGN relay neurons. Genetic deletion of CKAMP44 increases the rate of recovery from desensitisation of AMPA receptors in dLGN relay neurons. Genetic deletion of CKAMP44 reduces synaptic short-term depression in retinogeniculate synapses. The probability to induce plateau potentials is elevated in relay neurons of CKAMP44-/- mice. Eye-specific input segregation is unaffected in the dLGN of CKAMP44-/- mice. Deletion of CKAMP44 mildly affects dendritic arborisation of relay neurons in the dLGN. ABSTRACT Relay neurons of the dorsal lateral geniculate nucleus (dLGN) receive inputs from retinal ganglion cells via retinogeniculate synapses. These connections undergo pruning in the first two weeks after eye opening. The remaining connections are strengthened several-fold by the insertion of AMPA receptors (AMPARs) into weak or silent synapses. In this study, we found that the AMPAR auxiliary subunit CKAMP44 is required for receptor insertion and function of retinogeniculate synapses during development. Genetic deletion of CKAMP44 resulted in decreased synaptic strength and a higher number of silent synapses in young (P9-11) mice. Recovery from desensitisation of AMPA receptors was faster in CKAMP44 knockout (CKAMP44-/- ) than in wildtype mice. Moreover, loss of CKAMP44 increased the probability to induce plateau potentials, which are known to be important for eye-specific input segregation and retinogeniculate synapse maturation. The anatomy of relay neurons in the dLGN was changed in young CKAMP44-/- mice showing a transient increase in dendritic branching that normalised during later development (P26-33). Interestingly, input segregation in young CKAMP44-/- mice was not affected when compared to wildtype mice. These results demonstrate that CKAMP44 promotes maturation and modulates function of retinogeniculate synapses during early development of the visual system without affecting input segregation. Abstract figure legend AMPA receptor auxiliary subunit CKAMP44 influences synaptic function in retinogeniculate synapses of young mice. CKAMP44 unsilences synapses by recruiting AMPA receptors to the synapse. Furthermore, genetic deletion of CKAMP44 reduces short-term depression and increases the probability to elicit L-type Ca2+ channel-mediated plateau potentials. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Florian Hetsch
- Institute of Pathophysiology, Focus Program Translational Neurosciences (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Danni Wang
- Institute of Pathophysiology, Focus Program Translational Neurosciences (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Xufeng Chen
- Institute of Pathophysiology, Focus Program Translational Neurosciences (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Jiong Zhang
- Institute of Pathophysiology, Focus Program Translational Neurosciences (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Muhammad Aslam
- Institute of Pathophysiology, Focus Program Translational Neurosciences (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Marcel Kegel
- Institute of Pathophysiology, Focus Program Translational Neurosciences (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Henrik Tonner
- Experimental Ophthalmology, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131, Mainz, Germany
| | - Franz Grus
- Experimental Ophthalmology, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131, Mainz, Germany
| | - Jakob von Engelhardt
- Institute of Pathophysiology, Focus Program Translational Neurosciences (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128, Mainz, Germany
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24
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Almuslehi MSM, Sen MK, Shortland PJ, Mahns DA, Coorssen JR. Histological and Top-Down Proteomic Analyses of the Visual Pathway in the Cuprizone Demyelination Model. J Mol Neurosci 2022; 72:1374-1401. [PMID: 35644788 PMCID: PMC9170674 DOI: 10.1007/s12031-022-01997-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 03/07/2022] [Indexed: 10/27/2022]
Abstract
Abstract
A change in visual perception is a frequent early symptom of multiple sclerosis (MS), the pathoaetiology of which remains unclear. Following a slow demyelination process caused by 12 weeks of low-dose (0.1%) cuprizone (CPZ) consumption, histology and proteomics were used to investigate components of the visual pathway in young adult mice. Histological investigation did not identify demyelination or gliosis in the optic tracts, pretectal nuclei, superior colliculi, lateral geniculate nuclei or visual cortices. However, top-down proteomic assessment of the optic nerve/tract revealed a significant change in the abundance of 34 spots in high-resolution two-dimensional (2D) gels. Subsequent liquid chromatography-tandem mass spectrometry (LC-TMS) analysis identified alterations in 75 proteoforms. Literature mining revealed the relevance of these proteoforms in terms of proteins previously implicated in animal models, eye diseases and human MS. Importantly, 24 proteoforms were not previously described in any animal models of MS, eye diseases or MS itself. Bioinformatic analysis indicated involvement of these proteoforms in cytoskeleton organization, metabolic dysregulation, protein aggregation and axonal support. Collectively, these results indicate that continuous CPZ-feeding, which evokes a slow demyelination, results in proteomic changes that precede any clear histological changes in the visual pathway and that these proteoforms may be potential early markers of degenerative demyelinating conditions.
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Sokhadze G, Whyland KL, Bickford ME, Guido W. The organization of cholinergic projections in the visual thalamus of the mouse. J Comp Neurol 2022; 530:1081-1098. [PMID: 34448209 DOI: 10.1002/cne.25235] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/27/2021] [Accepted: 07/30/2021] [Indexed: 11/11/2022]
Abstract
Cholinergic projections from the brainstem serve as important modulators of activity in visual thalamic nuclei such as the dorsal lateral geniculate nucleus (dLGN). While these projections have been studied in several mammals, a comprehensive examination of their organization in the mouse is lacking. We used the retrograde transport of viruses or cholera toxin subunit B (CTB) injected in the dLGN, immunocytochemical labeling with antibodies against choline acetyltransferase (ChAT), brain nitric oxide synthase (BNOS), and vesicular acetylcholine transporter (VAChT), ChAT-Cre mice crossed with a reporter line (Ai9), as well as brainstem virus injections in ChAT-Cre mice to examine the pattern of thalamic innervation from cholinergic neurons in the pedunculopontine tegmental nucleus (PPTg), laterodorsal tegmental nucleus (LDTg), and the parabigeminal nucleus (PBG). Retrograde tracing demonstrated that the dLGN receives input from the PPTg, LDTg, and PBG. Viral tracing in ChAT-Cre mice and retrograde tracing combined with immunocytochemistry revealed that many of these inputs originate from cholinergic neurons in the PBG and PPTg. Most notable was an extensive cholinergic projection from the PBG which innervated most of the contralateral dLGN, with an especially dense concentration in the dorsolateral shell, as well as a small region in the dorsomedial pole of the ipsilateral dLGN. The PPTg was found to provide a sparse somewhat diffuse innervation of the ipsilateral dLGN. Neurons in the PPTg co-expressed ChAT, BNOS, and VAChT, whereas PBG neurons expressed ChAT, but not BNOS or VAChT. These results highlight the presence of distinct cholinergic populations that innervate the mouse dLGN.
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Affiliation(s)
- Guela Sokhadze
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Kyle L Whyland
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Martha E Bickford
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - William Guido
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
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26
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Somaiya RD, Huebschman NA, Chaunsali L, Sabbagh U, Carrillo GL, Tewari BP, Fox MA. Development of astrocyte morphology and function in mouse visual thalamus. J Comp Neurol 2022; 530:945-962. [PMID: 34636034 PMCID: PMC8957486 DOI: 10.1002/cne.25261] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 10/02/2021] [Accepted: 10/05/2021] [Indexed: 11/10/2022]
Abstract
The rodent visual thalamus has served as a powerful model to elucidate the cellular and molecular mechanisms that underlie sensory circuit formation and function. Despite significant advances in our understanding of the role of axon-target interactions and neural activity in orchestrating circuit formation in visual thalamus, the role of non-neuronal cells, such as astrocytes, is less clear. In fact, we know little about the transcriptional identity and development of astrocytes in mouse visual thalamus. To address this gap in knowledge, we studied the expression of canonical astrocyte molecules in visual thalamus using immunostaining, in situ hybridization, and reporter lines. While our data suggests some level of heterogeneity of astrocytes in different nuclei of the visual thalamus, the majority of thalamic astrocytes appeared to be labeled in Aldh1l1-EGFP mice. This led us to use this transgenic line to characterize the neonatal and postnatal development of these cells in visual thalamus. Our data show that not only have the entire cohort of astrocytes migrated into visual thalamus by eye-opening but they also have acquired their adult-like morphology, even while retinogeniculate synapses are still maturing. Furthermore, ultrastructural, immunohistochemical, and functional approaches revealed that by eye-opening, thalamic astrocytes ensheathe retinogeniculate synapses and are capable of efficient uptake of glutamate. Taken together, our results reveal that the morphological, anatomical, and functional development of astrocytes in visual thalamus occurs prior to eye-opening and the emergence of experience-dependent visual activity.
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Affiliation(s)
- Rachana D. Somaiya
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24016
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
| | - Natalie A. Huebschman
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
- Neuroscience Department, Ohio Wesleyan University, Delaware, OH 43015
| | - Lata Chaunsali
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
- School of Neuroscience Graduate Program, Virginia Tech, Blacksburg, VA 24061
| | - Ubadah Sabbagh
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24016
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
| | - Gabriela L. Carrillo
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24016
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
| | - Bhanu P. Tewari
- Neuroscience Department, School of Medicine, University of Virginia, Charlottesville, VA 22903
| | - Michael A. Fox
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
- School of Neuroscience, Virginia Tech, Blacksburg, VA 24061
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061
- Department of Pediatrics, Virginia Tech Carilion School of Medicine, Roanoke, VA 24016
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27
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Sun C, Zhang X, Ruzycki PA, Chen S. Essential Functions of MLL1 and MLL2 in Retinal Development and Cone Cell Maintenance. Front Cell Dev Biol 2022; 10:829536. [PMID: 35223853 PMCID: PMC8864151 DOI: 10.3389/fcell.2022.829536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 01/25/2022] [Indexed: 11/23/2022] Open
Abstract
MLL1 (KMT2A) and MLL2 (KMT2B) are homologous members of the mixed-lineage leukemia (MLL) family of histone methyltransferases involved in epigenomic transcriptional regulation. Their sequence variants have been associated with neurological and psychological disorders, but little is known about their roles and mechanism of action in CNS development. Using mouse retina as a model, we previously reported MLL1’s role in retinal neurogenesis and horizontal cell maintenance. Here we determine roles of MLL2 and MLL1/MLL2 together in retinal development using conditional knockout (CKO) mice. Deleting Mll2 from Chx10+ retinal progenitors resulted in a similar phenotype as Mll1 CKO, but removal of both alleles produced much more severe deficits than each single CKO: 1-month double CKO mutants displayed null light responses in electroretinogram; thin retinal layers, including shorter photoreceptor outer segments with impaired phototransduction gene expression; and reduced numbers of M-cones, horizontal and amacrine neurons, followed by fast retinal degeneration. Despite moderately reduced progenitor cell proliferation at P0, the neurogenic capacity was largely maintained in double CKO mutants. However, upregulated apoptosis and reactive gliosis were detected during postnatal retinal development. Finally, the removal of both MLLs in fated rods produced a normal phenotype, but the CKO in M-cones impaired M-cone function and survival, indicating both cell non-autonomous and autonomous mechanisms. Altogether, our results suggest that MLL1/MLL2 play redundant roles in maintaining specific retinal neurons after cell fate specification and are essential for establishing functional neural networks.
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Affiliation(s)
- Chi Sun
- Department of Ophthalmology and Visual Sciences, St. Louis, MO, United States
| | - Xiaodong Zhang
- Department of Ophthalmology and Visual Sciences, St. Louis, MO, United States
| | - Philip A. Ruzycki
- Department of Ophthalmology and Visual Sciences, St. Louis, MO, United States
| | - Shiming Chen
- Department of Ophthalmology and Visual Sciences, St. Louis, MO, United States
- Department of Developmental Biology, Washington University, St. Louis, MO, United States
- *Correspondence: Shiming Chen,
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28
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Bhandari A, Ward TW, Smith J, Van Hook MJ. Structural and functional plasticity in the dorsolateral geniculate nucleus of mice following bilateral enucleation. Neuroscience 2022; 488:44-59. [PMID: 35131394 PMCID: PMC8960354 DOI: 10.1016/j.neuroscience.2022.01.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 01/31/2022] [Indexed: 02/08/2023]
Abstract
Within the nervous system, plasticity mechanisms attempt to stabilize network activity following disruption by injury, disease, or degeneration. Optic nerve injury and age-related diseases can induce homeostatic-like responses in adulthood. We tested this possibility in the thalamocortical (TC) neurons in the dorsolateral geniculate nucleus (dLGN) using patch-clamp electrophysiology, optogenetics, immunostaining, and single-cell dendritic analysis following loss of visual input via bilateral enucleation. We observed progressive loss of vGlut2-positive retinal terminals in the dLGN indicating degeneration post-enucleation that was coincident with changes in microglial morphology indicative of microglial activation. Consistent with the decline of vGlut2 puncta, we also observed loss of retinogeniculate (RG) synaptic function assessed using optogenetic activation of RG axons while performing whole-cell voltage clamp recordings from TC neurons in brain slices. Surprisingly, we did not detect any significant changes in the frequency of miniature post-synaptic currents (mEPSCs) or corticothalamic feedback synapses. Analysis of TC neuron dendritic structure from single-cell dye fills revealed a gradual loss of dendrites proximal to the soma, where TC neurons receive the bulk of RG inputs. Finally, analysis of action potential firing demonstrated that TC neurons have increased excitability following enucleation, firing more action potentials in response to depolarizing current injections. Our findings show that degeneration of the retinal axons/optic nerve and loss of RG synaptic inputs induces structural and functional changes in TC neurons, consistent with neuronal attempts at compensatory plasticity in the dLGN.
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29
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Thalamic subnetworks as units of function. Nat Neurosci 2022; 25:140-153. [DOI: 10.1038/s41593-021-00996-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 12/07/2021] [Indexed: 01/15/2023]
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30
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Duménieu M, Marquèze-Pouey B, Russier M, Debanne D. Mechanisms of Plasticity in Subcortical Visual Areas. Cells 2021; 10:3162. [PMID: 34831385 PMCID: PMC8621502 DOI: 10.3390/cells10113162] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 01/10/2023] Open
Abstract
Visual plasticity is classically considered to occur essentially in the primary and secondary cortical areas. Subcortical visual areas such as the dorsal lateral geniculate nucleus (dLGN) or the superior colliculus (SC) have long been held as basic structures responsible for a stable and defined function. In this model, the dLGN was considered as a relay of visual information travelling from the retina to cortical areas and the SC as a sensory integrator orienting body movements towards visual targets. However, recent findings suggest that both dLGN and SC neurons express functional plasticity, adding unexplored layers of complexity to their previously attributed functions. The existence of neuronal plasticity at the level of visual subcortical areas redefines our approach of the visual system. The aim of this paper is therefore to review the cellular and molecular mechanisms for activity-dependent plasticity of both synaptic transmission and cellular properties in subcortical visual areas.
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Affiliation(s)
| | | | | | - Dominique Debanne
- INSERM, Aix-Marseille Université, UNIS, 13015 Marseille, France; (M.D.); (B.M.-P.); (M.R.)
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31
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Tehovnik EJ, Froudarakis E, Scala F, Smirnakis SM, Patel SS, Tolias AS. Visuomotor control in mice and primates. Neurosci Biobehav Rev 2021; 130:185-200. [PMID: 34416241 PMCID: PMC10508359 DOI: 10.1016/j.neubiorev.2021.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/30/2021] [Accepted: 08/09/2021] [Indexed: 12/01/2022]
Abstract
We conduct a comparative evaluation of the visual systems from the retina to the muscles of the mouse and the macaque monkey noting the differences and similarities between these two species. The topics covered include (1) visual-field overlap, (2) visual spatial resolution, (3) V1 cortical point-image [i.e., V1 tissue dedicated to analyzing a unit receptive field], (4) object versus motion encoding, (5) oculomotor range, (6) eye, head, and body movement coordination, and (7) neocortical and cerebellar function. We also discuss blindsight in rodents and primates which provides insights on how the neocortex mediates conscious vision in these species. This review is timely because the field of visuomotor neurophysiology is expanding beyond the macaque monkey to include the mouse; there is therefore a need for a comparative analysis between these two species on how the brain generates visuomotor responses.
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Affiliation(s)
- E J Tehovnik
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, TX, USA.
| | - E Froudarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion, Greece
| | - F Scala
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, TX, USA
| | - S M Smirnakis
- Department of Neurology, Brigham and Women's Hospital and Jamaica Plain Veterans Administration Hospital, Harvard Medical School, Boston, MA, USA
| | - S S Patel
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, TX, USA
| | - A S Tolias
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, TX, USA; Department of Electrical Engineering and Computer Engineering, Rice University, Houston, TX, USA
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32
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A cell-ECM mechanism for connecting the ipsilateral eye to the brain. Proc Natl Acad Sci U S A 2021; 118:2104343118. [PMID: 34654745 PMCID: PMC8545493 DOI: 10.1073/pnas.2104343118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2021] [Indexed: 12/11/2022] Open
Abstract
Distinct features of the visual world are transmitted from the retina to the brain through anatomically segregated circuits. Despite this being an organizing principle of visual pathways in mammals, we lack an understanding of the signaling mechanisms guiding axons of different types of retinal neurons into segregated layers of brain regions. We explore this question by identifying how axons from the ipsilateral retina innervate a specific lamina of the superior colliculus. Our studies reveal a unique cell–extracellular matrix recognition mechanism that specifies precise targeting of these axons to the superior colliculus. Loss of this mechanism not only resulted in the absence of this eye-specific visual circuit, but it led to an impairment of innate predatory visual behavior as well. Information about features in the visual world is parsed by circuits in the retina and is then transmitted to the brain by distinct subtypes of retinal ganglion cells (RGCs). Axons from RGC subtypes are stratified in retinorecipient brain nuclei, such as the superior colliculus (SC), to provide a segregated relay of parallel and feature-specific visual streams. Here, we sought to identify the molecular mechanisms that direct the stereotyped laminar targeting of these axons. We focused on ipsilateral-projecting subtypes of RGCs (ipsiRGCs) whose axons target a deep SC sublamina. We identified an extracellular glycoprotein, Nephronectin (NPNT), whose expression is restricted to this ipsiRGC-targeted sublamina. SC-derived NPNT and integrin receptors expressed by ipsiRGCs are both required for the targeting of ipsiRGC axons to the deep sublamina of SC. Thus, a cell–extracellular matrix (ECM) recognition mechanism specifies precise laminar targeting of ipsiRGC axons and the assembly of eye-specific parallel visual pathways.
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von Engelhardt J. Role of AMPA receptor desensitization in short term depression - lessons from retinogeniculate synapses. J Physiol 2021; 600:201-215. [PMID: 34197645 DOI: 10.1113/jp280878] [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: 05/27/2021] [Accepted: 06/28/2021] [Indexed: 12/22/2022] Open
Abstract
Repetitive synapse activity induces various forms of short-term plasticity. The role of presynaptic mechanisms such as residual Ca2+ and vesicle depletion in short-term facilitation and short-term depression is well established. On the other hand, the contribution of postsynaptic mechanisms such as receptor desensitization and saturation to short-term plasticity is less well known and often ignored. In this review, I will describe short-term plasticity in retinogeniculate synapses of relay neurons of the dorsal lateral geniculate nucleus (dLGN) to exemplify the synaptic properties that facilitate the contribution of AMPA receptor desensitization to short-term plasticity. These include high vesicle release probability, glutamate spillover and, importantly, slow recovery from desensitization of AMPA receptors. The latter is strongly regulated by the interaction of AMPA receptors with auxiliary proteins such as CKAMP44. Finally, I discuss the relevance of short-term plasticity in retinogeniculate synapses for the processing of visual information by LGN relay neurons.
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Affiliation(s)
- Jakob von Engelhardt
- Institute of Pathophysiology, Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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34
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Seo NY, Kim GH, Noh JE, Shin JW, Lee CH, Lee KJ. Selective Regional Loss of Cortical Synapses Lacking Presynaptic Mitochondria in the 5xFAD Mouse Model. Front Neuroanat 2021; 15:690168. [PMID: 34248509 PMCID: PMC8267061 DOI: 10.3389/fnana.2021.690168] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/27/2021] [Indexed: 12/27/2022] Open
Abstract
Synaptic loss in Alzheimer's disease (AD) is strongly correlated with cognitive impairment. Accumulating evidence indicates that amyloid pathology leads to synaptic degeneration and mitochondrial damage in AD. However, it remains unclear whether synapses and presynaptic mitochondria are differentially affected in various cortical regions of the AD brain at the ultrastructural level. Using serial block-face scanning electron microscopy, we assessed synaptic structures in the medial prefrontal cortex (mPFC) and primary visual cortex (V1) of the 5xFAD mouse model of AD. At 6 months of age, 5xFAD mice exhibited significantly elevated levels of amyloid deposition in layer 2/3 of the mPFC but not V1. Accordingly, three-dimensional reconstruction of synaptic connectivity revealed a significant reduction in excitatory synaptic density in layer 2 of the mPFC, but not V1, of male transgenic mice. Notably, the density of synapses lacking presynaptic mitochondria was selectively decreased in the mPFC of 5xFAD mice, with no change in the density of mitochondria-containing synapses. Further classification of spines into shape categories confirmed a preferential loss of thin spines whose presynaptic boutons were largely devoid of mitochondria in the 5xFAD mPFC. Furthermore, the number of mitochondria per bouton in spared mitochondria-containing boutons was reduced in the mPFC, but not V1, of 5xFAD mice. Collectively, these results highlight region-specific vulnerability of cortical synapses to amyloid deposition and suggest that the presence of presynaptic mitochondria may affect synaptic degeneration in AD.
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Affiliation(s)
- Na-Young Seo
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, South Korea.,Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, South Korea
| | - Gyu Hyun Kim
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Jeong Eun Noh
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Ji Won Shin
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Chan Hee Lee
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Kea Joo Lee
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, South Korea.,Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, South Korea
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35
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Qiu Y, Zhao Z, Klindt D, Kautzky M, Szatko KP, Schaeffel F, Rifai K, Franke K, Busse L, Euler T. Natural environment statistics in the upper and lower visual field are reflected in mouse retinal specializations. Curr Biol 2021; 31:3233-3247.e6. [PMID: 34107304 DOI: 10.1016/j.cub.2021.05.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 04/06/2021] [Accepted: 05/11/2021] [Indexed: 12/29/2022]
Abstract
Pressures for survival make sensory circuits adapted to a species' natural habitat and its behavioral challenges. Thus, to advance our understanding of the visual system, it is essential to consider an animal's specific visual environment by capturing natural scenes, characterizing their statistical regularities, and using them to probe visual computations. Mice, a prominent visual system model, have salient visual specializations, being dichromatic with enhanced sensitivity to green and UV in the dorsal and ventral retina, respectively. However, the characteristics of their visual environment that likely have driven these adaptations are rarely considered. Here, we built a UV-green-sensitive camera to record footage from mouse habitats. This footage is publicly available as a resource for mouse vision research. We found chromatic contrast to greatly diverge in the upper, but not the lower, visual field. Moreover, training a convolutional autoencoder on upper, but not lower, visual field scenes was sufficient for the emergence of color-opponent filters, suggesting that this environmental difference might have driven superior chromatic opponency in the ventral mouse retina, supporting color discrimination in the upper visual field. Furthermore, the upper visual field was biased toward dark UV contrasts, paralleled by more light-offset-sensitive ganglion cells in the ventral retina. Finally, footage recorded at twilight suggests that UV promotes aerial predator detection. Our findings support that natural scene statistics shaped early visual processing in evolution.
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Affiliation(s)
- Yongrong Qiu
- Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076 Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), International Max Planck Research School, University of Tübingen, 72076 Tübingen, Germany
| | - Zhijian Zhao
- Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076 Tübingen, Germany
| | - David Klindt
- Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076 Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), International Max Planck Research School, University of Tübingen, 72076 Tübingen, Germany
| | - Magdalena Kautzky
- Division of Neurobiology, Faculty of Biology, LMU Munich, 82152 Planegg-Martinsried, Germany; Graduate School of Systemic Neurosciences (GSN), LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Klaudia P Szatko
- Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076 Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), International Max Planck Research School, University of Tübingen, 72076 Tübingen, Germany; Bernstein Centre for Computational Neuroscience, 72076 Tübingen, Germany
| | - Frank Schaeffel
- Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany
| | - Katharina Rifai
- Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; Carl Zeiss Vision International GmbH, 73430 Aalen, Germany
| | - Katrin Franke
- Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076 Tübingen, Germany; Bernstein Centre for Computational Neuroscience, 72076 Tübingen, Germany
| | - Laura Busse
- Division of Neurobiology, Faculty of Biology, LMU Munich, 82152 Planegg-Martinsried, Germany; Bernstein Centre for Computational Neuroscience, 82152 Planegg-Martinsried, Germany.
| | - Thomas Euler
- Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076 Tübingen, Germany; Bernstein Centre for Computational Neuroscience, 72076 Tübingen, Germany.
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36
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Choi BJ, Chen YCD, Desplan C. Building a circuit through correlated spontaneous neuronal activity in the developing vertebrate and invertebrate visual systems. Genes Dev 2021; 35:677-691. [PMID: 33888564 PMCID: PMC8091978 DOI: 10.1101/gad.348241.121] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
During the development of the vertebrate nervous systems, genetic programs assemble an immature circuit that is subsequently refined by neuronal activity evoked by external stimuli. However, prior to sensory experience, the intrinsic property of the developing nervous system also triggers correlated network-level neuronal activity, with retinal waves in the developing vertebrate retina being the best documented example. Spontaneous activity has also been found in the visual system of Drosophila Here, we compare the spontaneous activity of the developing visual system between mammalian and Drosophila and suggest that Drosophila is an emerging model for mechanistic and functional studies of correlated spontaneous activity.
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Affiliation(s)
- Ben Jiwon Choi
- Department of Biology, New York University, New York, New York 10003, USA
| | | | - Claude Desplan
- Department of Biology, New York University, New York, New York 10003, USA
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37
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Van Hook MJ, Monaco C, Bierlein ER, Smith JC. Neuronal and Synaptic Plasticity in the Visual Thalamus in Mouse Models of Glaucoma. Front Cell Neurosci 2021; 14:626056. [PMID: 33584206 PMCID: PMC7873902 DOI: 10.3389/fncel.2020.626056] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 12/21/2020] [Indexed: 11/20/2022] Open
Abstract
Homeostatic plasticity plays important role in regulating synaptic and intrinsic neuronal function to stabilize output following perturbations to circuit activity. In glaucoma, a neurodegenerative disease of the visual system commonly associated with elevated intraocular pressure (IOP), the early disease is associated with altered synaptic inputs to retinal ganglion cells (RGCs), changes in RGC intrinsic excitability, and deficits in optic nerve transport and energy metabolism. These early functional changes can precede RGC degeneration and are likely to alter RGC outputs to their target structures in the brain and thereby trigger homeostatic changes in synaptic and neuronal properties in those brain regions. In this study, we sought to determine whether and how neuronal and synaptic function is altered in the dorsal lateral geniculate nucleus (dLGN), an important RGC projection target in the thalamus, and how functional changes related to IOP. We accomplished this using patch-clamp recordings from thalamocortical (TC) relay neurons in the dLGN in two established mouse models of glaucoma—the DBA/2J (D2) genetic mouse model and an inducible glaucoma model with intracameral microbead injections to elevate IOP. We found that the intrinsic excitability of TC neurons was enhanced in D2 mice and these functional changes were mirrored in recordings of TC neurons from microbead-injected mice. Notably, many neuronal properties were correlated with IOP in older D2 mice, when IOP rises. The frequency of miniature excitatory synaptic currents (mEPSCs) was reduced in 9-month-old D2 mice, and vGlut2 staining of RGC synaptic terminals was reduced in an IOP-dependent manner. These data suggest that glaucoma-associated changes to neuronal excitability and synaptic inputs in the dLGN might represent a combination of both stabilizing/homeostatic plasticity and pathological dysfunction.
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Affiliation(s)
- Matthew J Van Hook
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States.,Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, United States
| | - Corrine Monaco
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, United States.,Department of Obstetrics and Gynecology, Olson Center for Women's Health, University of Nebraska Medical Center, Omaha, NE, United States
| | - Elizabeth R Bierlein
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States.,Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States
| | - Jennie C Smith
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
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38
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Orlowska-Feuer P, Smyk MK, Alwani A, Lewandowski MH. Neuronal Responses to Short Wavelength Light Deficiency in the Rat Subcortical Visual System. Front Neurosci 2021; 14:615181. [PMID: 33488355 PMCID: PMC7815651 DOI: 10.3389/fnins.2020.615181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/08/2020] [Indexed: 12/26/2022] Open
Abstract
The amount and spectral composition of light changes considerably during the day, with dawn and dusk being the most crucial moments when light is within the mesopic range and short wavelength enriched. It was recently shown that animals use both cues to adjust their internal circadian clock, thereby their behavior and physiology, with the solar cycle. The role of blue light in circadian processes and neuronal responses is well established, however, an unanswered question remains: how do changes in the spectral composition of light (short wavelengths blocking) influence neuronal activity? In this study we addressed this question by performing electrophysiological recordings in image (dorsal lateral geniculate nucleus; dLGN) and non-image (the olivary pretectal nucleus; OPN, the suprachiasmatic nucleus; SCN) visual structures to determine neuronal responses to spectrally varied light stimuli. We found that removing short-wavelength from the polychromatic light (cut off at 525 nm) attenuates the most transient ON and sustained cells in the dLGN and OPN, respectively. Moreover, we compared the ability of different types of sustained OPN neurons (either changing or not their response profile to filtered polychromatic light) to irradiance coding, and show that both groups achieve it with equal efficacy. On the other hand, even very dim monochromatic UV light (360 nm; log 9.95 photons/cm2/s) evokes neuronal responses in the dLGN and SCN. To our knowledge, this is the first electrophysiological experiment supporting previous behavioral findings showing visual and circadian functions disruptions under short wavelength blocking environment. The current results confirm that neuronal activity in response to polychromatic light in retinorecipient structures is affected by removing short wavelengths, however, with type and structure – specific action. Moreover, they show that rats are sensitive to even very dim UV light.
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Affiliation(s)
- Patrycja Orlowska-Feuer
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University in Kraków, Kraków, Poland.,Department of Neurophysiology and Chronobiology, Jagiellonian University in Kraków, Kraków, Poland
| | - Magdalena Kinga Smyk
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University in Kraków, Kraków, Poland.,Department of Neurophysiology and Chronobiology, Jagiellonian University in Kraków, Kraków, Poland
| | - Anna Alwani
- Department of Neurophysiology and Chronobiology, Jagiellonian University in Kraków, Kraków, Poland
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Abstract
Retinal ganglion cells (RGCs) serve as a crucial communication channel from the retina to the brain. In the adult, these cells receive input from defined sets of presynaptic partners and communicate with postsynaptic brain regions to convey features of the visual scene. However, in the developing visual system, RGC interactions extend beyond their synaptic partners such that they guide development before the onset of vision. In this Review, we summarize our current understanding of how interactions between RGCs and their environment influence cellular targeting, migration and circuit maturation during visual system development. We describe the roles of RGC subclasses in shaping unique developmental responses within the retina and at central targets. Finally, we highlight the utility of RNA sequencing and genetic tools in uncovering RGC type-specific roles during the development of the visual system.
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Affiliation(s)
- Shane D'Souza
- The Visual Systems Group, Cincinnati Children's Hospital, Cincinnati, OH 45229, USA
- Center for Chronobiology, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital, Cincinnati, OH 45229, USA
- Molecular and Developmental Biology Graduate Program, University of Cincinnati, College of Medicine, Cincinnati, OH 45229, USA
| | - Richard A Lang
- The Visual Systems Group, Cincinnati Children's Hospital, Cincinnati, OH 45229, USA
- Center for Chronobiology, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital, Cincinnati, OH 45229, USA
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, OH 45229, USA
- Department of Ophthalmology, University of Cincinnati, College of Medicine, Cincinnati, OH 45229, USA
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40
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Neural Polyamory: One Cell Forms Meaningful Connections with Hundreds of Partners. Cell Syst 2020; 10:381-383. [PMID: 32437682 DOI: 10.1016/j.cels.2020.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Reconstruction of one thalamic neuron, mapping hundreds of presynaptic inputs and postsynaptic outputs, reveals diverse types of interaction in a neural microcircuit.
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41
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Differential Distribution of Ca 2+ Channel Subtypes at Retinofugal Synapses. eNeuro 2020; 7:ENEURO.0293-20.2020. [PMID: 33097488 PMCID: PMC7768275 DOI: 10.1523/eneuro.0293-20.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/06/2020] [Accepted: 10/20/2020] [Indexed: 02/06/2023] Open
Abstract
Retinofugal synapses serve as models for understanding how sensory signals from the periphery are relayed to the brain. Past studies have focused primarily on understanding the postsynaptic glutamatergic receptor subtypes involved in signal transmission, but the mechanisms underlying glutamate release at presynaptic retinal terminals remains largely unknown. Here we explored how different calcium (Ca2+) channel subtypes regulate glutamatergic excitatory synaptic transmission in two principal retinorecipient targets, the dorsal lateral geniculate nucleus (dLGN) and superior colliculus (SC) of the mouse. We used an in vitro slice preparation to record the synaptic responses of dLGN and SC neurons evoked by the electrical stimulation of optic tract (OT) fibers before and during the application of selective Ca2+ channel blockers. We found that synaptic responses to paired or repetitive OT stimulation were highly sensitive to extracellular levels of Ca2+ and to selective antagonists of voltage gated Ca2+ channels, indicating that these channels regulate the presynaptic release of glutamate at retinal synapses in both dLGN and SC. Bath application of selective Ca2+ channel blockers revealed that P/Q-type Ca2+ channels primarily operate to regulate glutamate release at retinal synapses in dLGN, while N-type Ca2+ channels dominate release in the SC.
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42
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Alvarado JA, Dhande OS, Prosseda PP, Kowal TJ, Ning K, Jabbehdari S, Hu Y, Sun Y. Developmental distribution of primary cilia in the retinofugal visual pathway. J Comp Neurol 2020; 529:1442-1455. [PMID: 32939774 DOI: 10.1002/cne.25029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 07/21/2020] [Accepted: 08/17/2020] [Indexed: 12/21/2022]
Abstract
The mammalian visual system is composed of circuitry connecting sensory input from the retina to the processing core of the visual cortex. The two main retinorecipient brain targets, the superior colliculus (SC) and dorsal lateral geniculate nucleus (dLGN), bridge retinal input and visual output. The primary cilium is a conserved organelle increasingly viewed as a critical sensor for the regulation of developmental and homeostatic pathways in most mammalian cell types. Moreover, cilia have been described as crucial for neurogenesis, neuronal maturation, and survival in the cortex and retina. However, cilia in the visual relay center remain to be fully described. In this study, we characterized the ciliation profile of the SC and dLGN and found that the overall number of ciliated cells declined during development. Interestingly, shorter ciliated cells in both regions were identified as neurons, whose numbers remained stable over time, suggesting that cilia retention is a critical feature for optimal neuronal function in SC and dLGN. Our study suggests that primary cilia are important for neuronal maturation and function in cells of the SC and dLGN.
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Affiliation(s)
- Jorge A Alvarado
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA
| | - Onkar S Dhande
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA
| | - Philipp P Prosseda
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA
| | - Tia J Kowal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA
| | - Ke Ning
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA
| | - Sayena Jabbehdari
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA.,Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA.,Wu Tsai Neurosciences Institute, Stanford University School of Medicine, Stanford, California, USA
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA.,Wu Tsai Neurosciences Institute, Stanford University School of Medicine, Stanford, California, USA.,Palo Alto Veterans Administration, Palo Alto, California, USA
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43
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Liang L, Chen C. Organization, Function, and Development of the Mouse Retinogeniculate Synapse. Annu Rev Vis Sci 2020; 6:261-285. [DOI: 10.1146/annurev-vision-121219-081753] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Visual information is encoded in distinct retinal ganglion cell (RGC) types in the eye tuned to specific features of the visual space. These streams of information project to the visual thalamus, the first station of the image-forming pathway. In the mouse, this connection between RGCs and thalamocortical neurons, the retinogeniculate synapse, has become a powerful experimental model for understanding how circuits in the thalamus are constructed to process these incoming lines of information. Using modern molecular and genetic tools, recent studies have suggested a more complex circuit organization than was previously understood. In this review, we summarize the current understanding of the structural and functional organization of the retinogeniculate synapse in the mouse. We discuss a framework by which a seemingly complex circuit can effectively integrate and parse information to downstream stations of the visual pathway. Finally, we review how activity and visual experience can sculpt this exquisite connectivity.
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Affiliation(s)
- Liang Liang
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115, USA
- Department of Neuroscience, Yale University, New Haven, Connecticut 06520, USA
| | - Chinfei Chen
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115, USA
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44
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Campbell PW, Govindaiah G, Masterson SP, Bickford ME, Guido W. Synaptic properties of the feedback connections from the thalamic reticular nucleus to the dorsal lateral geniculate nucleus. J Neurophysiol 2020; 124:404-417. [PMID: 32609582 PMCID: PMC7500366 DOI: 10.1152/jn.00757.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The thalamic reticular nucleus (TRN) is a shell-like structure comprised of GABAergic neurons that surrounds the dorsal thalamus. While playing a key role in modulating thalamocortical interactions, TRN inhibition of thalamic activity is often thought of as having an all-or-none impact. Although TRN neurons have a dynamic firing range, it remains unclear how variable rates of TRN activity gate thalamocortical transmission. To address this, we examined the ultrastructural features and functional synaptic properties of the feedback connections in the mouse thalamus between TRN and the dorsal lateral geniculate nucleus (dLGN), the principal relay of retinal signals to visual cortex. Using electron microscopy to identify TRN input to dLGN, we found that TRN terminals formed synapses with non-GABAergic postsynaptic profiles. Compared with other nonretinal terminals in dLGN, those from TRN were relatively large and tended to contact proximal regions of relay cell dendrites. To evoke TRN activity in dLGN, we adopted an optogenetic approach by expressing ChR2, or a variant (ChIEF) in TRN terminals. Both in vitro and in vivo recordings revealed that repetitive stimulation of TRN terminals led to a frequency-dependent inhibition of dLGN activity, with higher rates of stimulation resulting in increasing levels of membrane hyperpolarization and corresponding decreases in spike firing. This relationship suggests that alterations in TRN activity lead to graded changes in relay cell spike firing.NEW & NOTEWORTHY The thalamic reticular nucleus (TRN) modulates thalamocortical transmission through inhibition. In mouse, TRN terminals in the dorsal lateral geniculate nucleus (dLGN) form synapses with relay neurons but not interneurons. Stimulation of TRN terminals in dLGN leads to a frequency-dependent form of inhibition, with higher rates of stimulation leading to a greater suppression of spike firing. Thus, TRN inhibition appears more dynamic than previously recognized, having a graded rather than an all-or-none impact on thalamocortical transmission.
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Affiliation(s)
- Peter W. Campbell
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Gubbi Govindaiah
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Sean P. Masterson
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Martha E. Bickford
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky
| | - William Guido
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky
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45
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Cong Q, Soteros BM, Wollet M, Kim JH, Sia GM. The endogenous neuronal complement inhibitor SRPX2 protects against complement-mediated synapse elimination during development. Nat Neurosci 2020; 23:1067-1078. [PMID: 32661396 PMCID: PMC7483802 DOI: 10.1038/s41593-020-0672-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 06/16/2020] [Indexed: 02/06/2023]
Abstract
Complement-mediated synapse elimination has emerged as an important process in both brain development and neurological diseases, but whether neurons express complement inhibitors that protect synapses against complement-mediated synapse elimination remains unknown. Here, we show that the sushi domain protein SRPX2 is a neuronally expressed complement inhibitor that regulates complement-dependent synapse elimination. SRPX2 directly binds to C1q and blocks its activity, and SRPX2-/Y mice show increased C3 deposition and microglial synapse engulfment. They also show a transient decrease in synapse numbers and increase in retinogeniculate axon segregation in the lateral geniculate nucleus. In the somatosensory cortex, SRPX2-/Y mice show decreased thalamocortical synapse numbers and increased spine pruning. C3-/-;SRPX2-/Y double-knockout mice exhibit phenotypes associated with C3-/- mice rather than SRPX2-/Y mice, which indicates that C3 is necessary for the effect of SRPX2 on synapse elimination. Together, these results show that SRPX2 protects synapses against complement-mediated elimination in both the thalamus and the cortex.
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Affiliation(s)
- Qifei Cong
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Breeanne M Soteros
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Mackenna Wollet
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Jun Hee Kim
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Gek-Ming Sia
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
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46
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Li N, Gu Y. The Visual Pathway for Binocular Integration. Neurosci Bull 2020; 36:1089-1091. [PMID: 32367252 DOI: 10.1007/s12264-020-00506-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 02/13/2020] [Indexed: 01/09/2023] Open
Affiliation(s)
- Na Li
- State Key Laboratory of Medical Neurobiology and Ministry of Education Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Yu Gu
- State Key Laboratory of Medical Neurobiology and Ministry of Education Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China.
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47
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Van Hook MJ. Temperature effects on synaptic transmission and neuronal function in the visual thalamus. PLoS One 2020; 15:e0232451. [PMID: 32353050 PMCID: PMC7192487 DOI: 10.1371/journal.pone.0232451] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 04/15/2020] [Indexed: 12/11/2022] Open
Abstract
Numerous neuronal properties including the synaptic vesicle release process, neurotransmitter receptor complement, and postsynaptic ion channels are involved in transforming synaptic inputs into postsynaptic spiking. Temperature is a significant influencer of neuronal function and synaptic integration. Changing temperature can affect neuronal physiology in a diversity of ways depending on how it affects different members of the cell’s ion channel complement. Temperature’s effects on neuronal function are critical for pathological states such as fever, which can trigger seizure activity, but are also important in interpreting and comparing results of experiments conducted at room vs physiological temperature. The goal of this study was to examine the influence of temperature on synaptic properties and ion channel function in thalamocortical (TC) relay neurons in acute brain slices of the dorsal lateral geniculate nucleus, a key synaptic target of retinal ganglion cells in the thalamus. Warming the superfusate in patch clamp experiments with acutely-prepared brain slices led to an overall inhibition of synaptically-driven spiking behavior in TC neurons in response to a retinal ganglion cell spike train. Further study revealed that this was associated with an increase in presynaptic synaptic vesicle release probability and synaptic depression and altered passive and active membrane properties. Additionally, warming the superfusate triggered activation of an inwardly rectifying potassium current and altered the voltage-dependence of voltage-gated Na+ currents and T-type calcium currents. This study highlights the importance of careful temperature control in ex vivo physiological experiments and illustrates how numerous properties such as synaptic inputs, active conductances, and passive membrane properties converge to determine spike output.
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Affiliation(s)
- Matthew J. Van Hook
- Department of Ophthalmology & Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States of America
- * E-mail: ,
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48
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The evolutionary origin of visual and somatosensory representation in the vertebrate pallium. Nat Ecol Evol 2020; 4:639-651. [DOI: 10.1038/s41559-020-1137-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 02/05/2020] [Indexed: 12/16/2022]
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49
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Su J, Charalambakis NE, Sabbagh U, Somaiya RD, Monavarfeshani A, Guido W, Fox MA. Retinal inputs signal astrocytes to recruit interneurons into visual thalamus. Proc Natl Acad Sci U S A 2020; 117:2671-2682. [PMID: 31964831 PMCID: PMC7007527 DOI: 10.1073/pnas.1913053117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Inhibitory interneurons comprise a fraction of the total neurons in the visual thalamus but are essential for sharpening receptive field properties and improving contrast-gain of retinogeniculate transmission. During early development, these interneurons undergo long-range migration from germinal zones, a process regulated by the innervation of the visual thalamus by retinal ganglion cells. Here, using transcriptomic approaches, we identified a motogenic cue, fibroblast growth factor 15 (FGF15), whose expression in the visual thalamus is regulated by retinal input. Targeted deletion of functional FGF15 in mice led to a reduction in thalamic GABAergic interneurons similar to that observed in the absence of retinal input. This loss may be attributed, at least in part, to misrouting of interneurons into nonvisual thalamic nuclei. Unexpectedly, expression analysis revealed that FGF15 is generated by thalamic astrocytes and not retino-recipient neurons. Thus, these data show that retinal inputs signal through astrocytes to direct the long-range recruitment of interneurons into the visual thalamus.
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Affiliation(s)
- Jianmin Su
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
| | - Naomi E Charalambakis
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40202
| | - Ubadah Sabbagh
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061
| | - Rachana D Somaiya
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061
| | - Aboozar Monavarfeshani
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061
| | - William Guido
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40202;
| | - Michael A Fox
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016;
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061
- Department of Pediatrics, Virginia Tech Carilion School of Medicine, Roanoke, VA 24016
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Andrews MG, Nowakowski TJ. Human brain development through the lens of cerebral organoid models. Brain Res 2019; 1725:146470. [PMID: 31542572 PMCID: PMC6887101 DOI: 10.1016/j.brainres.2019.146470] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/21/2019] [Accepted: 09/18/2019] [Indexed: 01/01/2023]
Abstract
The brain is one of the most complex organs in the body, which emerges from a relatively simple set of basic 'building blocks' during early development according to complex cellular and molecular events orchestrated through a set of inherited instructions. Innovations in stem cell technologies have enabled modelling of neural cells using two- and three-dimensional cultures. In particular, cerebral ('brain') organoids have taken the center stage of brain development models that have the potential for providing meaningful insight into human neurodevelopmental and neurological disorders. We review the current understanding of cellular events during human brain organogenesis, and the events occurring during cerebral organoid differentiation. We highlight the strengths and weaknesses of this experimental model system. In particular, we explain evidence that organoids can mimic many aspects of early neural development, including neural induction, patterning, and broad neurogenesis and gliogenesis programs, offering the opportunity to study genetic regulation of these processes in a human context. Several shortcomings of the current culture methods limit the utility of cerebral organoids to spontaneously give rise to many important cell types, and to model higher order features of tissue organization. We suggest that future studies aim to improve these features in order to make them better models for the study of laminar organization, circuit formation and how disruptions of these processes relate to disease.
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Affiliation(s)
- Madeline G Andrews
- Department of Neurology, University of California, San Francisco, CA, USA; The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, USA.
| | - Tomasz J Nowakowski
- Department of Anatomy, University of California, San Francisco, CA, USA; Department of Psychiatry, University of California, San Francisco, CA, USA; Chan Zuckerberg Biohub, San Francisco, CA, USA.
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