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Negueruela S, Morenilla-Palao C, Sala S, Ordoño P, Herrera M, Coca Y, López-Cascales MT, Florez-Paz D, Gomis A, Herrera E. Proper Frequency of Perinatal Retinal Waves Is Essential for the Precise Wiring of Visual Axons in Nonimage-Forming Nuclei. J Neurosci 2024; 44:e1408232024. [PMID: 39151955 DOI: 10.1523/jneurosci.1408-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/05/2024] [Accepted: 08/07/2024] [Indexed: 08/19/2024] Open
Abstract
The development of the visual system is a complex and multistep process characterized by the precise wiring of retinal ganglion cell (RGC) axon terminals with their corresponding neurons in the visual nuclei of the brain. Upon reaching primary image-forming nuclei (IFN), such as the superior colliculus and the lateral geniculate nucleus, RGC axons undergo extensive arborization that refines over the first few postnatal weeks. The molecular mechanisms driving this activity-dependent remodeling process, which is influenced by waves of spontaneous activity in the developing retina, are still not well understood. In this study, by manipulating the activity of RGCs in mice from either sex and analyzing their transcriptomic profiles before eye-opening, we identified the Type I membrane protein synaptotagmin 13 (Syt13) as involved in spontaneous activity-dependent remodeling. Using these mice, we also explored the impact of spontaneous retinal activity on the development of other RGC recipient targets such as nonimage-forming (NIF) nuclei and demonstrated that proper frequency and duration of retinal waves occurring prior to visual experience are essential for shaping the connectivity of the NIF circuit. Together, these findings contribute to a deeper understanding of the molecular and physiological mechanisms governing activity-dependent axon refinement during the assembly of the visual circuit.
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Affiliation(s)
- Santiago Negueruela
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), San Juan de Alicante 03550, Spain
| | - Cruz Morenilla-Palao
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), San Juan de Alicante 03550, Spain
| | - Salvador Sala
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), San Juan de Alicante 03550, Spain
| | - Patricia Ordoño
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), San Juan de Alicante 03550, Spain
| | - Macarena Herrera
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), San Juan de Alicante 03550, Spain
| | - Yaiza Coca
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), San Juan de Alicante 03550, Spain
| | - Maria Teresa López-Cascales
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), San Juan de Alicante 03550, Spain
| | - Danny Florez-Paz
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), San Juan de Alicante 03550, Spain
| | - Ana Gomis
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), San Juan de Alicante 03550, Spain
| | - Eloísa Herrera
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), San Juan de Alicante 03550, Spain
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Zhang K, Su A, Wang Y, Crair M. Acetylcholine Promotes Directionally Biased Glutamatergic Retinal Waves. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.10.566639. [PMID: 38014271 PMCID: PMC10680594 DOI: 10.1101/2023.11.10.566639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Spontaneous retinal waves are a critical driving force for the self-organization of the mouse visual system prior to eye-opening. Classically characterized as taking place in three distinct stages defined by their primary excitatory drive, Stage II waves during the first postnatal week are propagated through the volume transmission of acetylcholine while Stage III retinal waves during the second postnatal week depend on glutamatergic transmission from bipolar cells. However, both late Stage II and early Stage III retinal waves share a defining propagation bias toward the temporal-to-nasal direction despite developmental changes in the underlying cholinergic and glutamatergic retinal networks. Here, we leverage genetic and pharmacological manipulations to investigate the relationship between cholinergic and glutamatergic neurotransmission during the transition between Stage II and Stage III waves in vivo. We find that the cholinergic network continues to play a vital role in the propagation of waves during Stage III after the primary mode of neurotransmission changes to glutamate. In the absence of glutamatergic waves, compensatory cholinergic activity persists but lacks the propagation bias typically observed in Stage III waves. In the absence of cholinergic waves, gap junction-mediated activity typically associated with Stage I waves persists throughout the developmental window in which Stage III waves usually emerge and lacks the spatiotemporal profile of normal Stage III waves, including a temporal-to-nasal propagation bias. Finally, we show that cholinergic signaling through β2 subunit-containing nicotinic acetylcholine receptors, essential for Stage II wave propagation, is also critical for Stage III wave directionality.
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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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Fujishiro T, Honjo M, Kawasaki H, Asaoka R, Yamagishi R, Aihara M. Structural Changes and Astrocyte Response of the Lateral Geniculate Nucleus in a Ferret Model of Ocular Hypertension. Int J Mol Sci 2020; 21:ijms21041339. [PMID: 32079216 PMCID: PMC7072923 DOI: 10.3390/ijms21041339] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/04/2020] [Accepted: 02/12/2020] [Indexed: 01/09/2023] Open
Abstract
We investigated structural changes and astrocyte responses of the lateral geniculate nucleus (LGN) in a ferret model of ocular hypertension (OH). In 10 ferrets, OH was induced via the injection of cultured conjunctival cells into the anterior chamber of the right eye; six normal ferrets were used as controls. Anterograde axonal tracing with cholera toxin B revealed that atrophic damage was evident in the LGN layers receiving projections from OH eyes. Immunohistochemical analysis with antibodies against NeuN, glial fibrillary acidic protein (GFAP), and Iba-1 was performed to specifically label neurons, astrocytes, and microglia in the LGN. Significantly decreased NeuN immunoreactivity and increased GFAP and Iba-1 immunoreactivities were observed in the LGN layers receiving projections from OH eyes. Interestingly, the changes in the immunoreactivities were significantly different among the LGN layers. The C layers showed more severe damage than the A and A1 layers. Secondary degenerative changes in the LGN were also observed, including neuronal damage and astrocyte reactions in each LGN layer. These results suggest that our ferret model of OH is valuable for investigating damages during the retina–brain transmission of the visual pathway in glaucoma. The vulnerability of the C layers was revealed for the first time.
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Affiliation(s)
- Takashi Fujishiro
- Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo 113-8655, Japan; (T.F.); (M.H.); (R.A.); (R.Y.)
| | - Megumi Honjo
- Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo 113-8655, Japan; (T.F.); (M.H.); (R.A.); (R.Y.)
| | - Hiroshi Kawasaki
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-1192, Japan;
| | - Ryo Asaoka
- Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo 113-8655, Japan; (T.F.); (M.H.); (R.A.); (R.Y.)
| | - Reiko Yamagishi
- Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo 113-8655, Japan; (T.F.); (M.H.); (R.A.); (R.Y.)
| | - Makoto Aihara
- Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo 113-8655, Japan; (T.F.); (M.H.); (R.A.); (R.Y.)
- Correspondence: ; Tel.: +81-3-3815-5411; Fax: +81-3-3817-0798
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Nakamoto C, Durward E, Horie M, Nakamoto M. Nell2 regulates the contralateral-versus-ipsilateral visual projection as a domain-specific positional cue. Development 2019; 146:dev.170704. [PMID: 30745429 DOI: 10.1242/dev.170704] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 01/29/2019] [Indexed: 01/15/2023]
Abstract
In mammals with binocular vision, retinal ganglion cell (RGC) axons from each eye project to eye-specific domains in the contralateral and ipsilateral dorsal lateral geniculate nucleus (dLGN), underpinning disparity-based stereopsis. Although domain-specific axon guidance cues that discriminate contralateral and ipsilateral RGC axons have long been postulated as a key mechanism for development of the eye-specific retinogeniculate projection, the molecular nature of such cues has remained elusive. Here, we show that the extracellular glycoprotein Nell2 (neural epidermal growth factor-like-like 2) is expressed in the dorsomedial region of the dLGN, which ipsilateral RGC axons terminate in and contralateral axons avoid. In Nell2 mutant mice, contralateral RGC axons abnormally invaded the ipsilateral domain of the dLGN, and ipsilateral axons terminated in partially fragmented patches, forming a mosaic pattern of contralateral and ipsilateral axon-termination zones. In vitro, Nell2 exerted inhibitory effects on contralateral, but not ipsilateral, RGC axons. These results provide evidence that Nell2 acts as a domain-specific positional label in the dLGN that discriminates contralateral and ipsilateral RGC axons, and that it plays essential roles in the establishment of the eye-specific retinogeniculate projection.
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Affiliation(s)
- Chizu Nakamoto
- Aberdeen Developmental Biology Group, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Elaine Durward
- Aberdeen Developmental Biology Group, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Masato Horie
- Department of CNS Research, Otsuka Pharmaceutical, 463-10 Kagasuno, Kawauchi-cho, Tokushima 771-0192, Japan
| | - Masaru Nakamoto
- Aberdeen Developmental Biology Group, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen AB25 2ZD, UK
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Failor SW, Ng A, Cheng HJ. Monocular enucleation alters retinal waves in the surviving eye. Neural Dev 2018; 13:4. [PMID: 29573745 PMCID: PMC5866508 DOI: 10.1186/s13064-018-0101-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 03/02/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Activity in neurons drives afferent competition that is critical for the refinement of nascent neural circuits. In ferrets, when an eye is lost in early development, surviving retinogeniculate afferents from the spared eye spread across the thalamus in a manner that is dependent on spontaneous retinal activity. However, how this spontaneous activity, also known as retinal waves, might dynamically regulate afferent terminal targeting remains unknown. METHODS We recorded retinal waves from retinae ex vivo using multi-electrode arrays. Retinae came from ferrets who were binocular or who had one eye surgically removed at birth. Linear mixed effects models were used to investigate the effects of early monocular enucleation on retinal wave activity. RESULTS When an eye is removed at birth, spontaneous bursts of action potentials by retinal ganglion cells (RGCs) in the surviving eye are shorter in duration. The shortening of RGC burst duration results in decreased pairwise RGC correlations across the retina and is associated with the retinal wave-dependent spread of retinogeniculate afferents previously reported in enucleates. CONCLUSION Our findings show that removal of the competing eye modulates retinal waves and could underlie the dynamic regulation of competition-based refinement during retinogeniculate development.
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Affiliation(s)
- Samuel Wilson Failor
- Center for Neuroscience, University of California, Davis, 1544 Newton Court, Davis, CA, 95618, USA. .,Wolfson Institute for Biomedical Research, University College London, Gower Street, London, WC1E 6BT, UK.
| | - Arash Ng
- Center for Neuroscience, University of California, Davis, 1544 Newton Court, Davis, CA, 95618, USA
| | - Hwai-Jong Cheng
- Center for Neuroscience, University of California, Davis, 1544 Newton Court, Davis, CA, 95618, USA. .,Department of Neurobiology, Physiology, and Behavior, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA. .,Department of Pathology and Laboratory Medicine, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
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Patel VC, Jurgens CWD, Krahe TE, Povlishock JT. Adaptive reorganization of retinogeniculate axon terminals in dorsal lateral geniculate nucleus following experimental mild traumatic brain injury. Exp Neurol 2016; 289:85-95. [PMID: 28038987 DOI: 10.1016/j.expneurol.2016.12.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/08/2016] [Accepted: 12/23/2016] [Indexed: 11/17/2022]
Abstract
The pathologic process in traumatic brain injury marked by delayed axonal loss, known as diffuse axonal injury (DAI), leads to partial deafferentation of neurons downstream of injured axons. This process is linked to persistent visual dysfunction following mild traumatic brain injury (mTBI), however, examination of deafferentation in humans is impossible with current technology. To investigate potential reorganization in the visual system following mTBI, we utilized the central fluid percussion injury (cFPI) mouse model of mTBI. We report that in the optic nerve of adult male C57BL/6J mice, axonal projections of retinal ganglion cells (RGCs) to their downstream thalamic target, dorsal lateral geniculate nucleus (dLGN), undergo DAI followed by scattered, widespread axon terminals loss within the dLGN at 4days post-injury. However, at 10days post-injury, significant reorganization of RGC axon terminals was found, suggestive of an adaptive neuroplastic response. While these changes persisted at 20days post-injury, the RGC axon terminal distribution did not recovery fully to sham-injury levels. Our studies also revealed that following DAI, the segregation of axon terminals from ipsilateral and contralateral eye projections remained consistent with normal adult mouse distribution. Lastly, our examination of the shell and core of dLGN suggested that different RGC subpopulations may vary in their susceptibility to injury or in their contribution to reorganization following injury. Collectively, these findings support the premise that subcortical axon terminal reorganization may contribute to recovery following mTBI, and that different neural phenotypes may vary in their contribution to this reorganization despite exposure to the same injury.
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Affiliation(s)
- Vishal C Patel
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA.
| | - Christopher W D Jurgens
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA.
| | - Thomas E Krahe
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA.
| | - John T Povlishock
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA.
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Cheng N, Khanbabaei M, Murari K, Rho JM. Disruption of visual circuit formation and refinement in a mouse model of autism. Autism Res 2016; 10:212-223. [PMID: 27529416 PMCID: PMC5324550 DOI: 10.1002/aur.1687] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/24/2016] [Accepted: 07/30/2016] [Indexed: 12/21/2022]
Abstract
Aberrant connectivity is believed to contribute to the pathophysiology of autism spectrum disorder (ASD). Recent neuroimaging studies have increasingly identified such impairments in patients with ASD, including alterations in sensory systems. However, the cellular substrates and molecular underpinnings of disrupted connectivity remain poorly understood. Utilizing eye‐specific segregation in the dorsal lateral geniculate nucleus (dLGN) as a model system, we investigated the formation and refinement of precise patterning of synaptic connections in the BTBR T + tf/J (BTBR) mouse model of ASD. We found that at the neonatal stage, the shape of the dLGN occupied by retinal afferents was altered in the BTBR group compared to C57BL/6J (B6) animals. Notably, the degree of overlap between the ipsi‐ and contralateral afferents was significantly greater in the BTBR mice. Moreover, these abnormalities continued into mature stage in the BTBR animals, suggesting persistent deficits rather than delayed maturation of axonal refinement. Together, these results indicate disrupted connectivity at the synaptic patterning level in the BTBR mice, suggesting that in general, altered neural circuitry may contribute to autistic behaviours seen in this animal model. In addition, these data are consistent with the notion that lower‐level, primary processing mechanisms contribute to altered visual perception in ASD. Autism Res2017, 10: 212–223. © 2016 The Authors Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research.
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Affiliation(s)
- Ning Cheng
- Developmental Neurosciences Research Program, Alberta Children's Hospital Research Institute (ACHRI), Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Maryam Khanbabaei
- Developmental Neurosciences Research Program, Alberta Children's Hospital Research Institute (ACHRI), Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Kartikeya Murari
- Department of Electrical and Computer Engineering, Schulich School of Engineering, University of Calgary, Calgary, Alberta, Canada
| | - Jong M Rho
- Departments of Pediatrics, Clinical Neurosciences, Physiology & Pharmacology, Alberta Children's Hospital Research Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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Owens MT, Feldheim DA, Stryker MP, Triplett JW. Stochastic Interaction between Neural Activity and Molecular Cues in the Formation of Topographic Maps. Neuron 2015; 87:1261-1273. [PMID: 26402608 DOI: 10.1016/j.neuron.2015.08.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 07/23/2015] [Accepted: 08/18/2015] [Indexed: 11/25/2022]
Abstract
Topographic maps in visual processing areas maintain the spatial order of the visual world. Molecular cues and neuronal activity both play critical roles in map formation, but their interaction remains unclear. Here, we demonstrate that when molecular- and activity-dependent cues are rendered nearly equal in force, they drive topographic mapping stochastically. The functional and anatomical representation of azimuth in the superior colliculus of heterozygous Islet2-EphA3 knockin (Isl2(EphA3/+)) mice is variable: maps may be single, duplicated, or a combination of the two. This heterogeneity is not due to genetic differences, since map organizations in individual mutant animals often differ between colliculi. Disruption of spontaneous waves of retinal activity resulted in uniform map organization in Isl2(EphA3/+) mice, demonstrating that correlated spontaneous activity is required for map heterogeneity. Computational modeling replicates this heterogeneity, revealing that molecular- and activity-dependent forces interact simultaneously and stochastically during topographic map formation.
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Affiliation(s)
- Melinda T Owens
- Center for Integrative Neuroscience and Departments of Physiology and Bioengineering & Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - David A Feldheim
- Molecular, Cell & Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Michael P Stryker
- Center for Integrative Neuroscience and Departments of Physiology and Bioengineering & Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jason W Triplett
- Molecular, Cell & Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA; Center for Neuroscience Research, Children's National Health System, Washington, DC 20010, USA.
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Failor S, Chapman B, Cheng HJ. Retinal waves regulate afferent terminal targeting in the early visual pathway. Proc Natl Acad Sci U S A 2015; 112:E2957-66. [PMID: 26038569 PMCID: PMC4460437 DOI: 10.1073/pnas.1506458112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Current models of retinogeniculate development have proposed that connectivity between the retina and the dorsal lateral geniculate nucleus (dLGN) is established by gradients of axon guidance molecules, to allow initial coarse connections, and by competitive Hebbian-like processes, to drive eye-specific segregation and refine retinotopy. Here we show that when intereye competition is eliminated by monocular enucleation, blocking cholinergic stage II retinal waves disrupts the intraeye competition-mediated expansion of the retinogeniculate projection and results in the permanent disorganization of its laminae. This disruption of stage II retinal waves also causes long-term impacts on receptive field size and fine-scale retinotopy in the dLGN. Our results reveal a novel role for stage II retinal waves in regulating retinogeniculate afferent terminal targeting by way of intraeye competition, allowing for correct laminar patterning and the even allocation of synaptic territory. These findings should contribute to answering questions regarding the role of neural activity in guiding the establishment of neural circuits.
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Affiliation(s)
- Samuel Failor
- Center for Neuroscience, University of California, Davis, CA 95618
| | - Barbara Chapman
- Center for Neuroscience, University of California, Davis, CA 95618; Department of Neurobiology, Physiology, and Behavior, University of California, Davis, CA 95616
| | - Hwai-Jong Cheng
- Center for Neuroscience, University of California, Davis, CA 95618; Department of Neurobiology, Physiology, and Behavior, University of California, Davis, CA 95616; Department of Pathology and Laboratory Medicine, University of California, Davis, CA 95616
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Davis ZW, Sun C, Derieg B, Chapman B, Cheng HJ. Epibatidine blocks eye-specific segregation in ferret dorsal lateral geniculate nucleus during stage III retinal waves. PLoS One 2015; 10:e0118783. [PMID: 25794280 PMCID: PMC4368645 DOI: 10.1371/journal.pone.0118783] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 01/18/2015] [Indexed: 11/18/2022] Open
Abstract
The segregation and maintenance of eye-specific inputs in the dorsal lateral geniculate nucleus (dLGN) during early postnatal development requires the patterned spontaneous activity of retinal waves. In contrast to the development of the mouse, ferret eye-specific segregation is not complete at the start of stage III glutamatergic retinal waves, and the remaining overlap is limited to the C/C1 lamina of the dLGN. To investigate the role of patterned spontaneous activity in this late segregation, we disrupted retinal waves pharmacologically for 5 day windows from postnatal day (P) 10 to P25. Multi-electrode array recordings of the retina in vitro reveal that the cholinergic agonist epibatidine disrupts correlated retinal activity during stage III waves. Epibatidine also prevents the segregation of eye-specific inputs in vivo during that period. Our results reveal a novel role for cholinergic influence on stage III retinal waves as an instructive signal for the continued segregation of eye-specific inputs in the ferret dLGN.
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Affiliation(s)
- Zachary W. Davis
- Center for Neuroscience, University of California Davis, Davis, California, United States of America
| | - Chao Sun
- Department of Neurobiology, Physiology, and Behavior, University of California Davis, Davis, California, United States of America
| | - Brittany Derieg
- Center for Neuroscience, University of California Davis, Davis, California, United States of America
| | - Barbara Chapman
- Center for Neuroscience, University of California Davis, Davis, California, United States of America
- Department of Neurobiology, Physiology, and Behavior, University of California Davis, Davis, California, United States of America
| | - Hwai-Jong Cheng
- Center for Neuroscience, University of California Davis, Davis, California, United States of America
- Department of Neurobiology, Physiology, and Behavior, University of California Davis, Davis, California, United States of America
- Department of Pathology and Laboratory Medicine, University of California Davis, Davis, California, United States of America
- * E-mail:
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12
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Speer CM, Sun C, Liets LC, Stafford BK, Chapman B, Cheng HJ. Eye-specific retinogeniculate segregation proceeds normally following disruption of patterned spontaneous retinal activity. Neural Dev 2014; 9:25. [PMID: 25377639 PMCID: PMC4289266 DOI: 10.1186/1749-8104-9-25] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 10/20/2014] [Indexed: 11/10/2022] Open
Abstract
Background Spontaneous retinal activity (SRA) is important during eye-specific segregation within the dorsal lateral geniculate nucleus (dLGN), but the feature(s) of activity critical for retinogeniculate refinement are controversial. Pharmacologically or genetically manipulating cholinergic signaling during SRA perturbs correlated retinal ganglion cell (RGC) spiking and disrupts eye-specific retinofugal refinement in vivo, consistent with an instructive role for SRA during visual system development. Paradoxically, ablating the starburst amacrine cells (SACs) that generate cholinergic spontaneous activity disrupts correlated RGC firing without impacting retinal activity levels or eye-specific segregation in the dLGN. Such experiments suggest that patterned SRA during retinal waves is not critical for eye-specific refinement and instead, normal activity levels are permissive for retinogeniculate development. Here we revisit the effects of ablating the cholinergic network during eye-specific segregation and show that SAC ablation disrupts, but does not eliminate, retinal waves with no concomitant impact on normal eye-specific segregation in the dLGN. Results We induced SAC ablation in postnatal ferret pups beginning at birth by intraocular injection of a novel immunotoxin selective for the ferret vesicular acetylcholine transporter (Ferret VAChT-Sap). Through dual-patch whole-cell and multi-electrode array recording we found that SAC ablation altered SRA patterns and led to significantly smaller retinal waves compared with controls. Despite these defects, eye-specific segregation was normal. Further, interocular competition for target territory in the dLGN proceeded in cases where SAC ablation was asymmetric in the two eyes. Conclusions Our data demonstrate normal eye-specific retinogeniculate development despite significant abnormalities in patterned SRA. Comparing our current results with earlier studies suggests that defects in retinal wave size, absolute levels of SRA, correlations between RGC pairs, RGC burst frequency, high frequency RGC firing during bursts, and the number of spikes per RGC burst are each uncorrelated with abnormalities in eye-specific segregation in the dLGN. An increase in the fraction of asynchronous spikes occurring outside of bursts and waves correlates with eye-specific segregation defects in studies reported to date. These findings highlight the relative importance of different features of SRA while providing additional constraints for computational models of Hebbian plasticity mechanisms in the developing visual system. Electronic supplementary material The online version of this article (doi:10.1186/1749-8104-9-25) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | - Hwai-Jong Cheng
- Center for Neuroscience, University of California, Davis, 1544 Newton Court, Davis, CA 95618, USA.
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Establishment of an experimental ferret ocular hypertension model for the analysis of central visual pathway damage. Sci Rep 2014; 4:6501. [PMID: 25308730 PMCID: PMC4194439 DOI: 10.1038/srep06501] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 08/21/2014] [Indexed: 11/20/2022] Open
Abstract
Glaucoma optic neuropathy (GON) is a condition where pathogenic intraocular pressure (IOP) results in axonal damage following retinal ganglion cell (RGC) death, and further results in secondary damage of the lateral geniculate nucleus (LGN). Therapeutic targets for glaucoma thus focus on both the LGN and RGC. However, the temporal and spatial patterns of degeneration and the mechanism of LGN damage have not been fully elucidated. Suitable and convenient ocular hypertension (OH) animal models with binocular vision comparable to that of monkeys are strongly needed. The ferret is relatively small mammal with binocular vision like humans – here we report on its suitability for investigating LGN. We developed a new method to elevate IOP by injection of cultured conjunctival cells into the anterior chamber to obstruct aqueous outflow. Histologically, cultured conjunctival cells successfully proliferated to occlude the angle, and IOP was elevated for 13 weeks after injection. Macroscopically, the size of the eye gradually expanded. Subsequent enlargement of optic nerve head cupping and atrophic damage of LGN projected from the OH eye were clearly observed by anterograde staining with cholera toxin B. We believe the ferret may be a promising OH model to investigate secondary degeneration of central nervous system including LGN.
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14
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Assali A, Gaspar P, Rebsam A. Activity dependent mechanisms of visual map formation--from retinal waves to molecular regulators. Semin Cell Dev Biol 2014; 35:136-46. [PMID: 25152335 DOI: 10.1016/j.semcdb.2014.08.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 08/12/2014] [Accepted: 08/15/2014] [Indexed: 01/31/2023]
Abstract
The refinement of neural connections requires activity-dependent mechanisms in addition to the genetic program initially establishing wiring diagrams. The well-understood organization of the visual system makes it an accessible model for analyzing the contribution of activity in the formation of connectivity. Prior to visual experience, patterned spontaneous activity in the form of retinal waves has an important role for the establishment of eye-specific and retinotopic maps by acting on the refinement of axon arborization. In the present review, which focuses on experimental data obtained in mice and ferrets, we highlight the features of retinal activity that are important for visual map formation and question whether synaptic release and Hebbian based competition rules apply to this system. Recent evidence using genetic tools that allowed the manipulation of different features of neural activity have clarified the controversy on whether activity is instructive or permissive for visual map formation. Furthermore, current evidence strongly suggests that different mechanisms are at play for different types of axons (ipsilateral vs. contralateral), maps (eye-specific vs. retinotopic) or targets. Many molecules that either modulate activity or are modulated by activity are important in the formation of the visual map, such as adenylate cyclase 1, serotonin, or molecules from the immune system. Finally, new players in the game include retrograde messengers signaling from the target cell to the retinal axons as well as microglia that could help to eliminate inappropriate synapses.
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Affiliation(s)
- Ahlem Assali
- Inserm UMR-S839, Paris, 75005, France; Université Pierre & Marie Curie (UPMC), Sorbonne Universités, Paris, France; Institut du Fer à Moulin, Paris, 75005, France.
| | - Patricia Gaspar
- Inserm UMR-S839, Paris, 75005, France; Université Pierre & Marie Curie (UPMC), Sorbonne Universités, Paris, France; Institut du Fer à Moulin, Paris, 75005, France.
| | - Alexandra Rebsam
- Inserm UMR-S839, Paris, 75005, France; Université Pierre & Marie Curie (UPMC), Sorbonne Universités, Paris, France; Institut du Fer à Moulin, Paris, 75005, France.
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15
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Kirkby LA, Sack GS, Firl A, Feller MB. A role for correlated spontaneous activity in the assembly of neural circuits. Neuron 2014; 80:1129-44. [PMID: 24314725 DOI: 10.1016/j.neuron.2013.10.030] [Citation(s) in RCA: 210] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2013] [Indexed: 11/28/2022]
Abstract
Before the onset of sensory transduction, developing neural circuits spontaneously generate correlated activity in distinct spatial and temporal patterns. During this period of patterned activity, sensory maps develop and initial coarse connections are refined, which are critical steps in the establishment of adult neural circuits. Over the last decade, there has been substantial evidence that altering the pattern of spontaneous activity disrupts refinement, but the mechanistic understanding of this process remains incomplete. In this review, we discuss recent experimental and theoretical progress toward the process of activity-dependent refinement, focusing on circuits in the visual, auditory, and motor systems. Although many outstanding questions remain, the combination of several novel approaches has brought us closer to a comprehensive understanding of how complex neural circuits are established by patterned spontaneous activity during development.
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Affiliation(s)
- Lowry A Kirkby
- Biophysics Graduate Group, UC Berkeley, Berkeley, CA 94720, USA
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16
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Chung WS, Clarke LE, Wang GX, Stafford BK, Sher A, Chakraborty C, Joung J, Foo LC, Thompson A, Chen C, Smith SJ, Barres BA. Astrocytes mediate synapse elimination through MEGF10 and MERTK pathways. Nature 2013; 504:394-400. [PMID: 24270812 PMCID: PMC3969024 DOI: 10.1038/nature12776] [Citation(s) in RCA: 896] [Impact Index Per Article: 81.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 10/11/2013] [Indexed: 12/14/2022]
Abstract
To achieve its precise neural connectivity, the developing mammalian nervous system undergoes extensive activity-dependent synapse remodeling. Recently microglial cells have been shown to be responsible for a portion of synaptic remodeling, but the remaining mechanisms remain mysterious. Here we report a new role for astrocytes in actively engulfing CNS synapses. This process helps to mediate synapse elimination, requires the Megf10 and Mertk phagocytic pathways, and is strongly dependent on neuronal activity. Developing mice deficient in both astrocyte pathways fail to normally refine their retinogeniculate connections and retain excess functional synapses. Lastly, we show that in the adult mouse brain, astrocytes continuously engulf both excitatory and inhibitory synapses. These studies reveal a novel role for astrocytes in mediating synapse elimination in the developing and adult brain, identify Megf10 and Mertk as critical players in the synapse remodeling underlying neural circuit refinement, and have important implications for understanding learning and memory as well as neurological disease processes.
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Affiliation(s)
- Won-Suk Chung
- Department of Neurobiology, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Laura E Clarke
- Department of Neurobiology, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Gordon X Wang
- Department of Molecular and Cellular Physiology, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Benjamin K Stafford
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Alexander Sher
- Santa Cruz Institute of Particle Physic and Department of Physics, University of California, Santa Cruz, CA 95064
| | - Chandrani Chakraborty
- Department of Neurobiology, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Julia Joung
- Department of Neurobiology, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Lynette C Foo
- Institute of Molecular and Cell Biology, AStar, 61 Biopolis Drive, Proteos Building, Singapore 138673
| | - Andrew Thompson
- Children's Hospital, Harvard Medical School, 300 Longwood Ave., CLS12250, Boston, MA 02115
| | - Chinfei Chen
- Children's Hospital, Harvard Medical School, 300 Longwood Ave., CLS12250, Boston, MA 02115
| | - Stephen J Smith
- Department of Molecular and Cellular Physiology, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Ben A Barres
- Department of Neurobiology, Stanford University, School of Medicine, Stanford, CA 94305, USA
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17
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Effects of early postnatal alcohol exposure on the developing retinogeniculate projections in C57BL/6 mice. Alcohol 2013; 47:173-9. [PMID: 23402901 DOI: 10.1016/j.alcohol.2012.12.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 12/21/2012] [Accepted: 12/24/2012] [Indexed: 12/13/2022]
Abstract
Previous studies on the adverse effects of perinatal exposure to ethanol (EtOH) on the developing visual system mainly focused on retinal and optic nerve morphology. The aim of the present study was to investigate whether earlier reported retinal and optic nerve changes are accompanied by anomalies in eye-specific fiber segregation in the dorsal lateral geniculate nucleus (dLGN). C57BL/6 mice pups were exposed to ethanol by intragastric intubation at either 3 or 4 g/kg from postnatal days (PD) 3-10, the third trimester equivalent to human gestation. Control (C) and intubation control (IC) groups not exposed to ethanol were included. On PD9, retinogeniculate projections were labeled by intraocular microinjections of cholera toxin-β (CTB) either conjugated to Alexa 488 (green) or 594 (red) administrated to the left and right eye, respectively. Pups were sacrificed 24 h after the last CTB injection. The results showed that ethanol exposure decreased the total number of dLGN neurons and significantly reduced the total dLGN projection as well as the contralateral and ipsilateral projection areas.
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18
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Retinal waves coordinate patterned activity throughout the developing visual system. Nature 2012; 490:219-25. [PMID: 23060192 DOI: 10.1038/nature11529] [Citation(s) in RCA: 327] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 08/20/2012] [Indexed: 11/08/2022]
Abstract
The morphological and functional development of the vertebrate nervous system is initially governed by genetic factors and subsequently refined by neuronal activity. However, fundamental features of the nervous system emerge before sensory experience is possible. Thus, activity-dependent development occurring before the onset of experience must be driven by spontaneous activity, but the origin and nature of activity in vivo remains largely untested. Here we use optical methods to show in live neonatal mice that waves of spontaneous retinal activity are present and propagate throughout the entire visual system before eye opening. This patterned activity encompassed the visual field, relied on cholinergic neurotransmission, preferentially initiated in the binocular retina and exhibited spatiotemporal correlations between the two hemispheres. Retinal waves were the primary source of activity in the midbrain and primary visual cortex, but only modulated ongoing activity in secondary visual areas. Thus, spontaneous retinal activity is transmitted through the entire visual system and carries patterned information capable of guiding the activity-dependent development of complex intra- and inter-hemispheric circuits before the onset of vision.
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19
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Yamamoto N, López-Bendito G. Shaping brain connections through spontaneous neural activity. Eur J Neurosci 2012; 35:1595-604. [PMID: 22607005 DOI: 10.1111/j.1460-9568.2012.08101.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An overwhelming number of observations demonstrate that neural activity and genetic programs interact to specify the composition and organization of neural circuits during all stages of development. Spontaneous neuronal activities have been documented in several developing neural regions in both invertebrates and vertebrates, and their roles are mostly conserved among species. Among these roles, Ca(2+) spikes and levels of electrical activity have been shown to regulate neurite growth, axon extension and axon branching. Here, we review selected findings concerning the role of spontaneous activity on circuit development.
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Affiliation(s)
- Nobuhiko Yamamoto
- Laboratory of Cellular and Molecular Neurobiology, Graduate School of Frontier Biosciences, Osaka University, Yamadaoka, Suita, Osaka, Japan.
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20
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Kampf-Lassin A, Wei J, Galang J, Prendergast BJ. Experience-independent development of the hamster circadian visual system. PLoS One 2011; 6:e16048. [PMID: 21556133 PMCID: PMC3083388 DOI: 10.1371/journal.pone.0016048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 12/06/2010] [Indexed: 12/03/2022] Open
Abstract
Experience-dependent functional plasticity is a hallmark of the primary visual system, but it is not known if analogous mechanisms govern development of the circadian visual system. Here we investigated molecular, anatomical, and behavioral consequences of complete monocular light deprivation during extended intervals of postnatal development in Syrian hamsters. Hamsters were raised in constant darkness and opaque contact lenses were applied shortly after eye opening and prior to the introduction of a light-dark cycle. In adulthood, previously-occluded eyes were challenged with visual stimuli. Whereas image-formation and motion-detection were markedly impaired by monocular occlusion, neither entrainment to a light-dark cycle, nor phase-resetting responses to shifts in the light-dark cycle were affected by prior monocular deprivation. Cholera toxin-b subunit fluorescent tract-tracing revealed that in monocularly-deprived hamsters the density of fibers projecting from the retina to the suprachiasmatic nucleus (SCN) was comparable regardless of whether such fibers originated from occluded or exposed eyes. In addition, long-term monocular deprivation did not attenuate light-induced c-Fos expression in the SCN. Thus, in contrast to the thalamocortical projections of the primary visual system, retinohypothalamic projections terminating in the SCN develop into normal adult patterns and mediate circadian responses to light largely independent of light experience during development. The data identify a categorical difference in the requirement for light input during postnatal development between circadian and non-circadian visual systems.
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Affiliation(s)
- August Kampf-Lassin
- Department of Psychology, The University of Chicago, Chicago, Illinois, United States of America.
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21
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Mouse mutants for the nicotinic acetylcholine receptor ß2 subunit display changes in cell adhesion and neurodegeneration response genes. PLoS One 2011; 6:e18626. [PMID: 21547082 PMCID: PMC3081876 DOI: 10.1371/journal.pone.0018626] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 03/08/2011] [Indexed: 11/19/2022] Open
Abstract
Mice lacking expression of the ß2 subunit of the neuronal nicotinic acetylcholine receptor (CHRNB2) display abnormal retinal waves and a dispersed projection of retinal ganglion cell (RGC) axons to their dorsal lateral geniculate nuclei (dLGNs). Transcriptomes of LGN tissue from two independently generated Chrnb2−/− mutants and from wildtype mice were obtained at postnatal day 4 (P4), during the normal period of segregation of eye-specific afferents to the LGN. Microarray analysis reveals reduced expression of genes located on the cell membrane or in extracellular space, and of genes active in cell adhesion and calcium signaling. In particular, mRNA for cadherin 1 (Cdh1), a known axon growth regulator, is reduced to nearly undetectable levels in the LGN of P4 mutant mice and Lypd2 mRNA is similarly suppressed. Similar analysis of retinal tissue shows increased expression of crumbs 1 (Crb1) and chemokine (C-C motif) ligand 21 (Ccl21) mRNAs in Chrnb2−/− mutant animals. Mutations in these genes are associated with retinal neuronal degeneration. The retinas of Chrnb2−/− mutants are normal in appearance, but the increased expression of these genes may also be involved in the abnormal projection patterns of RGC to the LGN. These data may provide the tools to distinguish the interplay between neural activity and molecular expression. Finally, comparison of the transcriptomes of the two different Chrnb2−/− mutant strains reveals the effects of genetic background upon gene expression.
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22
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Padmanabhan K, Eddy WF, Crowley JC. A novel algorithm for optimal image thresholding of biological data. J Neurosci Methods 2010; 193:380-4. [PMID: 20817033 DOI: 10.1016/j.jneumeth.2010.08.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 08/26/2010] [Accepted: 08/26/2010] [Indexed: 11/26/2022]
Abstract
With the proliferation of both in vivo and in vitro microscopy techniques in the neurosciences, increased attention has been placed on the development of image analysis techniques. As experiments can produce large numbers of high bit depth images, automated processing methods have become necessary for handling these data sets. Thresholding, whereby a high bit depth image is converted into a binary image in order to identify a feature of interest, is one such standard automated technique; but the method of selecting an appropriate threshold value is far from standard. We present a novel algorithm, maximum correlation thresholding (MCT), that thresholds images accurately and efficiently without relying on any assumptions of the statistics of the image. As MCT produces thresholded images that preserve the most salient elements in the image, the algorithm performs as well as a trained user on a range of neurobiological data and in a variety of noisy conditions or when preprocessing steps preceded the thresholding operation. Our method will thus allow neuroscientists to automate image thresholding using a robust, computationally efficient algorithm, ultimately aiding in accurate image quantification and analysis.
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Affiliation(s)
- Krishnan Padmanabhan
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA.
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23
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Speer CM, Mikula S, Huberman AD, Chapman B. The developmental remodeling of eye-specific afferents in the ferret dorsal lateral geniculate nucleus. Anat Rec (Hoboken) 2010; 293:1-24. [PMID: 20039439 DOI: 10.1002/ar.21001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Eye-specific projections to the dorsal lateral geniculate nucleus (dLGN) serve as a model for exploring how precise patterns of circuitry form during development in the mammalian central nervous system. Using a combination of dual-label anterograde retinogeniculate tracing and Nissl-staining, we studied the patterns of eye-specific afferents and cellular laminae in the dLGN of the pigmented sable ferret at eight developmental timepoints between birth and adulthood. Each time point was investigated in the three standard orthogonal planes of section, allowing us to generate a complete anatomical map of eye-specific development in this species. We find that eye-specific retinal ganglion cell axon segregation varies according to location in the dLGN, with the principle contralateral (A) and ipsilateral layers (A1) maturing first, followed by the contralateral and ipsilateral C laminae. Cytoarchitectural lamination lags behind eye-specific segregation, except in the C laminae where underlying cellular layers never develop to accompany eye-specific afferent domains. The emergence of On/Off sublaminae occurs following eye-specific segregation in this species. On the basis of these findings, we constructed a three-dimensional map of eye-specific channels in the developing and mature ferret dLGN.
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Affiliation(s)
- Colenso M Speer
- Center for Neuroscience, University of California, Davis, Davis, California 95618, USA
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24
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Eglen SJ, Gjorgjieva J. Self-organization in the developing nervous system: theoretical models. HFSP JOURNAL 2009; 3:176-85. [PMID: 19639040 DOI: 10.2976/1.3079539] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Accepted: 01/20/2009] [Indexed: 01/07/2023]
Abstract
Sensory maps in the nervous system often connect to each other in a topographic fashion. This is most strikingly seen in the visual system, where neighboring neurons in the retina project to neighboring neurons in the target structure, such as the superior colliculus. This article discusses the developmental mechanisms that are involved in the formation of topographic maps, with an emphasis on the role of theoretical models in helping us to understand these mechanisms. Recent experimental advances in studying the roles of guidance molecules and patterns of spontaneous activity mean that there are new challenges to be addressed by theoretical models. Key questions include understanding what instructional cues are present in the patterns of spontaneous activity, and how activity and guidance molecules might interact. Our discussion concludes by comparing development of visual maps with development of maps in the olfactory system, where the influence of neural activity seems to differ.
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Affiliation(s)
- Stephen J Eglen
- Cambridge Computational Biology Institute, Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom
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25
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Iwai L, Kawasaki H. Molecular development of the lateral geniculate nucleus in the absence of retinal waves during the time of retinal axon eye-specific segregation. Neuroscience 2009; 159:1326-37. [PMID: 19409202 DOI: 10.1016/j.neuroscience.2009.02.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 01/05/2009] [Accepted: 02/05/2009] [Indexed: 11/29/2022]
Abstract
When retinal waves are inhibited binocularly, eye-specific segregation of retinal axons is disrupted, and retinal axons from the two eyes remain intermingled in the lateral geniculate nucleus (LGN). This effect of binocular retinal wave inhibition is mediated by the lack of activity-dependent competition between retinal axons from the two eyes, but it is unknown whether this effect is also mediated by the developmental arrest of the LGN in an immature state. Here we find developmental markers of the LGN during eye-specific segregation. The expression levels of Purkinje cell protein 4 (PCP4/PEP19), transcription factor 7-like 2 (TCF7L2/TCF4) and LIM homeobox protein 9 (Lhx9) in the LGN change significantly during eye-specific segregation. Using PCP4, TCF7L2 and Lhx9 as developmental markers of the LGN, we examine whether LGN development is affected by binocular disruption of retinal waves during eye-specific segregation. Binocular injection of epibatidine strongly inhibits eye-specific segregation, whereas it does not affect the expression of PCP4, TCF7L2 and Lhx9. Furthermore, the expression of PCP4, TCF7L2 and Lhx9 is normal in binocularly enucleated animals and in mice treated with the monoamine oxidase A (MAOA) inhibitor, clorgyline. In addition, our experiments using LGN slice cultures show that the expression of PCP4 and TCF7L2 in LGN slices changes as in vivo. Our results suggest that LGN development proceeds, at least in part, even in the absence of retinal inputs. PCP4, TCF7L2 and Lhx9 should be useful to examine LGN development during eye-specific segregation in mice and in ferrets.
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Affiliation(s)
- L Iwai
- Department of Molecular and Systems Neurobiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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26
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Sun C, Speer CM, Wang GY, Chapman B, Chalupa LM. Epibatidine application in vitro blocks retinal waves without silencing all retinal ganglion cell action potentials in developing retina of the mouse and ferret. J Neurophysiol 2008; 100:3253-63. [PMID: 18922954 DOI: 10.1152/jn.90303.2008] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Epibatidine (EPI), a potent cholinergic agonist, disrupts acetylcholine-dependent spontaneous retinal activity. Early patch-clamp recordings in juvenile ferrets suggested that EPI blocks all retinal ganglion cell (RGC) action potentials when applied to the retina. In contrast, recent experiments on the developing mouse that relied on multielectrode array (MEA) recordings reported that EPI application decorrelates the activity of neighboring RGCs and eliminates retinal waves while preserving the spiking activity of many neurons. The different techniques used in previous studies raise the question of whether EPI has different effects on RGC activity in mouse compared with that in ferret. A resolution of this issue is essential for interpreting the results of developmental studies that relied on EPI to manipulate retinal activity. Our goal was to compare the effects of EPI on the spontaneous discharges of RGCs in mouse and ferret using 60-electrode MEA as well as patch-clamp recordings during the developmental stage when retinal waves are driven by acetylcholine in both species. We found that in both mouse and ferret EPI decorrelates RGC activity and eliminates retinal waves. However, EPI does not block all spontaneous activity in either species. Instead, our whole cell recordings reveal that EPI silences more than half of all RGCs while significantly increasing the activity of the remainder. These results have important implications for interpreting the results of previous studies that relied on this cholinergic agonist to perturb retinal activity.
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Affiliation(s)
- Chao Sun
- Department of Neurobiology, Physiology, and Behavior, School of Medicine, University of California, Davis, CA 95616, USA
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27
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Huberman AD, Feller MB, Chapman B. Mechanisms underlying development of visual maps and receptive fields. Annu Rev Neurosci 2008; 31:479-509. [PMID: 18558864 DOI: 10.1146/annurev.neuro.31.060407.125533] [Citation(s) in RCA: 442] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Patterns of synaptic connections in the visual system are remarkably precise. These connections dictate the receptive field properties of individual visual neurons and ultimately determine the quality of visual perception. Spontaneous neural activity is necessary for the development of various receptive field properties and visual feature maps. In recent years, attention has shifted to understanding the mechanisms by which spontaneous activity in the developing retina, lateral geniculate nucleus, and visual cortex instruct the axonal and dendritic refinements that give rise to orderly connections in the visual system. Axon guidance cues and a growing list of other molecules, including immune system factors, have also recently been implicated in visual circuit wiring. A major goal now is to determine how these molecules cooperate with spontaneous and visually evoked activity to give rise to the circuits underlying precise receptive field tuning and orderly visual maps.
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Affiliation(s)
- Andrew D Huberman
- Department of Neurobiology, Stanford University School of Medicine, Palo Alto, California 94305, USA.
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28
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Architecture and activity-mediated refinement of axonal projections from a mosaic of genetically identified retinal ganglion cells. Neuron 2008; 59:425-38. [PMID: 18701068 DOI: 10.1016/j.neuron.2008.07.018] [Citation(s) in RCA: 224] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 07/04/2008] [Accepted: 07/08/2008] [Indexed: 11/21/2022]
Abstract
Our understanding of how mammalian sensory circuits are organized and develop has long been hindered by the lack of genetic markers of neurons with discrete functions. Here, we report a transgenic mouse selectively expressing GFP in a complete mosaic of transient OFF-alpha retinal ganglion cells (tOFF-alphaRGCs). This enabled us to relate the mosaic spacing, dendritic anatomy, and electrophysiology of these RGCs to their complete map of projections in the brain. We find that tOFF-alphaRGCs project exclusively to the superior colliculus (SC) and dorsal lateral geniculate nucleus and are restricted to a specific laminar depth within each of these targets. The axons of tOFF-alphaRGC are also organized into columns in the SC. Both laminar and columnar specificity develop through axon refinement. Disruption of cholinergic retinal waves prevents the emergence of columnar- but not laminar-specific tOFF-alphaRGC connections. Our findings reveal that in a genetically identified sensory map, spontaneous activity promotes synaptic specificity by segregating axons arising from RGCs of the same subtype.
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29
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Butts DA, Kanold PO, Shatz CJ. A burst-based "Hebbian" learning rule at retinogeniculate synapses links retinal waves to activity-dependent refinement. PLoS Biol 2007; 5:e61. [PMID: 17341130 PMCID: PMC1808114 DOI: 10.1371/journal.pbio.0050061] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Accepted: 12/29/2006] [Indexed: 12/01/2022] Open
Abstract
Patterned spontaneous activity in the developing retina is necessary to drive synaptic refinement in the lateral geniculate nucleus (LGN). Using perforated patch recordings from neurons in LGN slices during the period of eye segregation, we examine how such burst-based activity can instruct this refinement. Retinogeniculate synapses have a novel learning rule that depends on the latencies between pre- and postsynaptic bursts on the order of one second: coincident bursts produce long-lasting synaptic enhancement, whereas non-overlapping bursts produce mild synaptic weakening. It is consistent with “Hebbian” development thought to exist at this synapse, and we demonstrate computationally that such a rule can robustly use retinal waves to drive eye segregation and retinotopic refinement. Thus, by measuring plasticity induced by natural activity patterns, synaptic learning rules can be linked directly to their larger role in instructing the patterning of neural connectivity. The brain is comprised of an immense number of connections between neurons, and clever strategies are required to achieve the correct wiring during development. One common strategy uses neural activity itself as feedback to instruct individual connections (synapses) through synaptic learning rules that delineate which patterns of activity strengthen the synapse and which weaken it. Throughout life, such activity-dependent synaptic changes are likely driven by experience and are thought to underlie learning and memory, but during early stages of development, they are often driven by activity spontaneously generated within the brain. Here, we study connections in the visual pathway between the retina and lateral geniculate nucleus (LGN), which—to develop correctly—require spontaneous “retinal waves” before the eye is responsive to light. By replaying the retinal wave activity as it appears at single LGN synapses, we observe a novel learning rule that describes a relatively simple computation for the developing synapse in the context of retinal wave activity. We then demonstrate how this learning rule is matched to properties of the retinal waves in order to robustly drive the synaptic refinement that occurs in the visual system. A novel learning rule describes a simple computation by which retinal wave activity robustly drives the synaptic refinement that occurs in the visual system.
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Affiliation(s)
- Daniel A Butts
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, United States of America.
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30
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Erskine L, Herrera E. The retinal ganglion cell axon's journey: insights into molecular mechanisms of axon guidance. Dev Biol 2007; 308:1-14. [PMID: 17560562 DOI: 10.1016/j.ydbio.2007.05.013] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 05/02/2007] [Accepted: 05/10/2007] [Indexed: 02/02/2023]
Abstract
The developing visual system has proven to be one of the most informative models for studying axon guidance decisions. The pathway is composed of the axons of a single neuronal cell type, the retinal ganglion cell (RGC), that navigate through a series of intermediate targets on route to their final destination. The molecular basis of optic pathway development is beginning to be elucidated with cues such as netrins, Slits and ephrins playing a key role. Other factors best characterised for their role as morphogens in patterning developing tissues, such as sonic hedgehog (Shh) and Wnts, also act directly on RGC axons to influence guidance decisions. The transcriptional basis of the spatial-temporal expression of guidance cues and their cognate receptors within the developing optic pathway as well as mechanisms underlying the plasticity of guidance responses also are starting to be understood. This review will focus on our current understanding of the molecular mechanisms directing the early development of functional connections in the developing visual system and the insights these studies have provided into general mechanisms of axon guidance.
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Affiliation(s)
- Lynda Erskine
- Division of Visual Science, Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK.
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31
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Höltje M, Brunk I, Grosse J, Beyer E, Veh RW, Bergmann M, Grosse G, Ahnert-Hilger G. Differential distribution of voltage-gated potassium channels Kv 1.1-Kv1.6 in the rat retina during development. J Neurosci Res 2007; 85:19-33. [PMID: 17075900 DOI: 10.1002/jnr.21105] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The discharge behavior of neurons depends on a variable expression and sorting pattern of voltage-dependent potassium (Kv) channels that changes during development. The rodent retina represents a neuronal network whose main functions develop after birth. To obtain information about neuronal maturation we analyzed the expression of subunits of the Kv1 subfamily in the rat retina during postnatal development using immunocytochemistry and immunoelectron microscopy. At postnatal day 5 (P5) all the alpha-subunits of Kv1.1-Kv1.6 channels were found to be expressed in the ganglion cell layer (GCL), most of them already at P1 or P3. Their expression upregulates postnatally and the pattern and distribution change in an isoform-specific manner. Additionally Kv1 channels are found in the outer and inner plexiform layer (OPL, IPL) and in the inner nuclear layer (INL) at different postnatal stages. In adult retina the Kv 1.3 channel localizes to the inner and outer segments of cones. In contrast, Kv1.4 is highly expressed in the outer retina at P8. In adult retina Kv1.4 occurs in rod inner segments (RIS) near the connecting cilium where it colocalizes with synapse associated protein SAP 97. By using confocal laser scanning microscopy we showed a differential localization of Kv1.1-1.6 to cholinergic amacrine and rod bipolar cells of the INL of the adult retina.
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Affiliation(s)
- M Höltje
- Institut für Integrative Neuroanatomie, Centrum für Anatomie, Charité-Universitätsmedizin Berlin, Berlin, Germany
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32
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Huberman AD. Mechanisms of eye-specific visual circuit development. Curr Opin Neurobiol 2007; 17:73-80. [PMID: 17254766 DOI: 10.1016/j.conb.2007.01.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Accepted: 01/15/2007] [Indexed: 02/04/2023]
Abstract
Eye-specific visual connections are a prominent model system for exploring how precise circuits develop in the CNS and, in particular, for addressing the role of neural activity in synapse elimination and axon refinement. Recent experiments have identified the features of spontaneous retinal activity that mediate eye-specific retinogeniculate segregation, the synaptic events associated with this process, and the importance of axon guidance cues for organizing the overall layout of eye-specific maps. The classic model of ocular dominance column development, in which spontaneous retinal activity plays a crucial role, has also gained new support. Although many outstanding questions remain, the mechanisms that instruct eye-specific circuit development are becoming clear.
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Affiliation(s)
- Andrew D Huberman
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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Huberman AD, Speer CM, Chapman B. Spontaneous retinal activity mediates development of ocular dominance columns and binocular receptive fields in v1. Neuron 2007; 52:247-54. [PMID: 17046688 PMCID: PMC2647846 DOI: 10.1016/j.neuron.2006.07.028] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Revised: 06/15/2006] [Accepted: 07/26/2006] [Indexed: 11/21/2022]
Abstract
The mechanisms that give rise to ocular dominance columns (ODCs) during development are controversial. Early experiments indicated a key role for retinal activity in ODC formation. However, later studies showed that in those early experiments, the retinal activity perturbation was initiated after ODCs had already formed. Moreover, recent studies concluded that early eye removals do not impact ODC segregation. Here we blocked spontaneous retinal activity during the very early stages of ODC development. This permanently disrupted the anatomical organization of ODCs and led to a dramatic increase in receptive field size for binocular cells in primary visual cortex. Our data suggest that early spontaneous retinal activity conveys crucial information about whether thalamocortical axons represent one or the other eye and that this activity mediates binocular competition important for shaping receptive fields in primary visual cortex.
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Affiliation(s)
- Andrew D. Huberman
- Center for Neuroscience University of California, Davis Davis, California 95616
| | - Colenso M. Speer
- Center for Neuroscience University of California, Davis Davis, California 95616
| | - Barbara Chapman
- Center for Neuroscience University of California, Davis Davis, California 95616
- Section of Neurobiology, Physiology, and Behavior University of California, Davis Davis, California 95616
- Correspondence:
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Flett DL, Lim CH, Ho SM, Mark RF, Marotte LR. Retinocollicular synaptogenesis and synaptic transmission during formation of the visual map in the superior colliculus of the wallaby (Macropus eugenii). Eur J Neurosci 2006; 23:3043-50. [PMID: 16819993 DOI: 10.1111/j.1460-9568.2006.04831.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Spontaneous retinal activity has been implicated in the development of the topographic map in the superior colliculus (SC) but a direct demonstration that it reaches the colliculus is lacking. Here we investigate when the retinocollicular projection is capable of transmitting information from the retina in a marsupial mammal, the wallaby (Macropus eugenii). The projection develops postnatally, allowing in vivo analysis throughout development. Quantification of retinocollicular synaptogenesis has been combined with electrophysiology of the development and characteristics of retinocollicular transmission, including in vivo and in vitro recording in the same animals. Prior to postnatal day (P) 12-14 in vitro recording detected only presynaptic activity in retinal axons in the colliculus, in response to stimulation of the optic nerve. Postsynaptic responses, comprising both N-methyl-d-aspartate (NMDA) and non-NMDA responses, were first detected in vitro at P12-14 and retinal synapses were identified. In contrast, postsynaptic responses to optic nerve stimulation could not be detected in vivo until P39, around the time that retinal axons begin arborizing. Around this age density and numbers of total synapses began increasing in the retinorecipient layers of the colliculus. By P55-64, the numbers of retinal synapses had increased significantly and density and numbers of retinal and total synapses continued to increase up to P94-99. During this time the map is undergoing refinement and degenerating axons and synapses were present. The discrepancy between in vitro and in vivo onset of functional connections raises the question of when retinal activity reaches collicular cells in the intact, unanaesthetized animal and this will require investigation.
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Affiliation(s)
- D L Flett
- Central Nervous System Stability and Degeneration Group, Research School of Biological Sciences, Australian National University, Canberra, ACT 0200, Australia
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35
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Price DJ, Kennedy H, Dehay C, Zhou L, Mercier M, Jossin Y, Goffinet AM, Tissir F, Blakey D, Molnár Z. The development of cortical connections. Eur J Neurosci 2006; 23:910-20. [PMID: 16519656 DOI: 10.1111/j.1460-9568.2006.04620.x] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The cortex receives its major sensory input from the thalamus via thalamocortical axons, and cortical neurons are interconnected in complex networks by corticocortical and callosal axons. Our understanding of the mechanisms generating the circuitry that confers functional properties on cortical neurons and networks, although poor, has been advanced significantly by recent research on the molecular mechanisms of thalamocortical axonal guidance and ordering. Here we review recent advances in knowledge of how thalamocortical axons are guided and how they maintain order during that process. Several studies have shown the importance in this process of guidance molecules including Eph receptors and ephrins, members of the Wnt signalling pathway and members of a novel planar cell polarity pathway. Signalling molecules and transcription factors expressed with graded concentrations across the cortex are important in establishing cortical maps of the topography of sensory surfaces. Neural activity, both spontaneous and evoked, plays a role in refining thalamocortical connections but recent work has indicated that neural activity is less important than was previously thought for the development of some early maps. A strategy used widely in the development of corticocortical and callosal connections is the early overproduction of projections followed by selection after contact with the target structure. Here we discuss recent work in primates indicating that elimination of juvenile projections is not a major mechanism in the development of pathways feeding information forward to higher levels of cortical processing, although its use is common to developing feedback pathways.
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Affiliation(s)
- David J Price
- Centre for Integrative Physiology, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK.
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Cang J, Rentería RC, Kaneko M, Liu X, Copenhagen DR, Stryker MP. Development of precise maps in visual cortex requires patterned spontaneous activity in the retina. Neuron 2006; 48:797-809. [PMID: 16337917 PMCID: PMC2562716 DOI: 10.1016/j.neuron.2005.09.015] [Citation(s) in RCA: 214] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2005] [Revised: 08/12/2005] [Accepted: 09/13/2005] [Indexed: 11/29/2022]
Abstract
The visual cortex is organized into retinotopic maps that preserve an orderly representation of the visual world, achieved by topographically precise inputs from the lateral geniculate nucleus. We show here that geniculocortical mapping is imprecise when the waves of spontaneous activity in the retina during the first postnatal week are disrupted genetically. This anatomical mapping defect is present by postnatal day 8 and has functional consequences, as revealed by optical imaging and microelectrode recording in adults. Pharmacological disruption of these retinal waves during the first week phenocopies the mapping defect, confirming both the site and the timing of the disruption in neural activity responsible for the defect. Analysis shows that the geniculocortical miswiring is not a trivial or necessary consequence of the retinogeniculate defect. Our findings demonstrate that disrupting early spontaneous activity in the eye alters thalamic connections to the cortex.
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Affiliation(s)
- Jianhua Cang
- W. M. Keck Foundation Center for Integrative Neuroscience, Department of Physiology, University of California, San Francisco, San Francisco, California 94143
| | - René C. Rentería
- Departments of Ophthalmology and Physiology, University of California, San Francisco, San Francisco, California 94143
| | - Megumi Kaneko
- W. M. Keck Foundation Center for Integrative Neuroscience, Department of Physiology, University of California, San Francisco, San Francisco, California 94143
| | - Xiaorong Liu
- Departments of Ophthalmology and Physiology, University of California, San Francisco, San Francisco, California 94143
| | - David R. Copenhagen
- Departments of Ophthalmology and Physiology, University of California, San Francisco, San Francisco, California 94143
| | - Michael P. Stryker
- W. M. Keck Foundation Center for Integrative Neuroscience, Department of Physiology, University of California, San Francisco, San Francisco, California 94143
- *Correspondence:
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37
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Jaubert-Miazza L, Green E, Lo FS, Bui K, Mills J, Guido W. Structural and functional composition of the developing retinogeniculate pathway in the mouse. Vis Neurosci 2005; 22:661-76. [PMID: 16332277 DOI: 10.1017/s0952523805225154] [Citation(s) in RCA: 178] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Accepted: 07/27/2005] [Indexed: 11/06/2022]
Abstract
The advent of transgenic mice has made the developing retinogeniculate pathway a model system for targeting potential mechanisms that underlie the refinement of sensory connections. However, a detailed characterization of the form and function of this pathway is lacking. Here we use a variety of anatomical and electrophysiological techniques to delineate the structural and functional changes occurring in the lateral geniculate nucleus (LGN) of dorsal thalamus of the C57/BL6 mouse. During the first two postnatal weeks there is an age-related recession in the amount of terminal space occupied by retinal axons arising from the two eyes. During the first postnatal week, crossed and uncrossed axons show substantial overlap throughout most of the LGN. Between the first and second week retinal arbors show significant pruning, so that by the time of natural eye opening (P12–14) segregation is complete and retinal projections are organized into distinct eye-specific domains. During this time of rapid anatomical rearrangement, LGN cells could be readily distinguished using immunocytochemical markers that stain for NMDA receptors, GABA receptors, L-type Ca2+channels, and the neurofilament protein SMI-32. Moreover, the membrane properties and synaptic responses of developing LGN cells are remarkably stable and resemble those of mature neurons. However, there are some notable developmental changes in synaptic connectivity. At early ages, LGN cells are binocularly responsive and receive input from as many as 11 different retinal ganglion cells. Optic tract stimulation also evokes plateau-like depolarizations that are mediated by the activation of L-type Ca2+channels. As retinal inputs from the two eyes segregate into nonoverlapping territories, there is a loss of binocular responsiveness, a decrease in retinal convergence, and a reduction in the incidence of plateau potentials. These data serve as a working framework for the assessment of phenotypes of genetically altered strains as well as provide some insight as to the molecular mechanisms underlying the refinement of retinogeniculate connections.
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Affiliation(s)
- Lisa Jaubert-Miazza
- Department of Cell Biology and Anatomy, Louisiana State Health Sciences Center, New Orleans, LA 70112, USA
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38
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Abstract
The selective elimination of axons, dendrites, axon and dendrite branches, and synapses, without loss of the parent neurons, occurs during normal development of the nervous system as well as in response to injury or disease in the adult. The widespread developmental phenomena of exuberant axonal projections and synaptic connections require both small-scale and large-scale axon pruning to generate precise adult connectivity, and they provide a mechanism for neural plasticity in the developing and adult nervous system, as well as a mechanism to evolve differences between species in a projection system. Such pruning is also required to remove axonal connections damaged in the adult, to stabilize the affected neural circuits, and to initiate their repair. Pruning occurs through either retraction or degeneration. Here we review examples of these phenomena and consider potential cellular and molecular mechanisms that underlie axon retraction and degeneration and how they might relate to each other in development and disease.
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Affiliation(s)
- Liqun Luo
- Department of Biological Sciences, Neurosciences Program, Stanford University, Stanford, CA 94305, USA.
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39
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Huberman AD, Murray KD, Warland DK, Feldheim DA, Chapman B. Ephrin-As mediate targeting of eye-specific projections to the lateral geniculate nucleus. Nat Neurosci 2005; 8:1013-21. [PMID: 16025110 PMCID: PMC2652399 DOI: 10.1038/nn1505] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2005] [Accepted: 06/23/2005] [Indexed: 11/09/2022]
Abstract
Axon guidance cues contributing to the development of eye-specific visual projections to the lateral geniculate nucleus (LGN) have not previously been identified. Here we show that gradients of ephrin-As and their receptors (EphAs) direct retinal ganglion cell (RGC) axons from the two eyes into their stereotyped pattern of layers in the LGN. Overexpression of EphAs in ferret RGCs using in vivo electroporation induced axons from both eyes to misproject within the LGN. The effects of EphA overexpression were competition-dependent and restricted to the early postnatal period. These findings represent the first demonstration of eye-specific pathfinding mediated by axon guidance cues and, taken with other reports, indicate that ephrin-As can mediate several mapping functions within individual target structures.
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Affiliation(s)
- Andrew D Huberman
- Center for Neuroscience, 1544 Newton Ct., University of California, Davis, California 95616, USA
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40
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Pfeiffenberger C, Cutforth T, Woods G, Yamada J, Rentería RC, Copenhagen DR, Flanagan JG, Feldheim DA. Ephrin-As and neural activity are required for eye-specific patterning during retinogeniculate mapping. Nat Neurosci 2005; 8:1022-7. [PMID: 16025107 PMCID: PMC1352169 DOI: 10.1038/nn1508] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2005] [Accepted: 06/24/2005] [Indexed: 01/28/2023]
Abstract
In mammals, retinal ganglion cell (RGC) projections initially intermingle and then segregate into a stereotyped pattern of eye-specific layers in the dorsal lateral geniculate nucleus (dLGN). Here we found that in mice deficient for ephrin-A2, ephrin-A3 and ephrin-A5, eye-specific inputs segregated but the shape and location of eye-specific layers were profoundly disrupted. In contrast, mice that lacked correlated retinal activity did not segregate eye-specific inputs. Inhibition of correlated neural activity in ephrin mutants led to overlapping retinal projections that were located in inappropriate regions of the dLGN. Thus, ephrin-As and neural activity act together to control patterning of eye-specific retinogeniculate layers.
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Affiliation(s)
- Cory Pfeiffenberger
- Department of Molecular, Cellular, and Developmental Biology, University of California at Santa Cruz, Santa Cruz, California 95064, USA
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41
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Torborg CL, Feller MB. Spontaneous patterned retinal activity and the refinement of retinal projections. Prog Neurobiol 2005; 76:213-35. [PMID: 16280194 DOI: 10.1016/j.pneurobio.2005.09.002] [Citation(s) in RCA: 205] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Revised: 08/30/2005] [Accepted: 09/22/2005] [Indexed: 11/22/2022]
Abstract
A characteristic feature of sensory circuits is the existence of orderly connections that represent maps of sensory space. A major research focus in developmental neurobiology is to elucidate the relative contributions of neural activity and guidance molecules in sensory map formation. Two model systems for addressing map formation are the retinotopic map formed by retinal projections to the superior colliculus (SC) (or its non-mammalian homolog, the optic tectum (OT)), and the eye-specific map formed by retinal projections to the lateral geniculate nucleus of the thalamus. In mammals, a substantial portion of retinotopic and eye-specific refinement of retinal axons occurs before vision is possible, but at a time when there is a robust, patterned spontaneous retinal activity called retinal waves. Though complete blockade of retinal activity disrupts normal map refinement, attempts at more refined perturbations, such as pharmacological and genetic manipulations that alter features of retinal waves critical for map refinement, remain controversial. Here we review: (1) the mechanisms that underlie the generation of retinal waves; (2) recent experiments that have investigated a role for guidance molecules and retinal activity in map refinement; and (3) experiments that have implicated various signaling cascades, both in retinal ganglion cells (RGCs) and their post-synaptic targets, in map refinement. It is likely that an understanding of retinal activity, guidance molecules, downstream signaling cascades, and the interactions between these biological systems will be critical to elucidating the mechanisms of sensory map formation.
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Affiliation(s)
- Christine L Torborg
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0357, USA
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42
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Lyckman AW, Fan G, Rios M, Jaenisch R, Sur M. Normal eye-specific patterning of retinal inputs to murine subcortical visual nuclei in the absence of brain-derived neurotrophic factor. Vis Neurosci 2005; 22:27-36. [PMID: 15842738 DOI: 10.1017/s095252380522103x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2004] [Indexed: 11/05/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is a preferred ligand for a member of the tropomyosin-related receptor family, trkB. Activation of trkB is implicated in various activity-independent as well as activity-dependent growth processes in many developing and mature neural systems. In the subcortical visual system, where electrical activity has been implicated in normal development, both differential survival, as well as remodeling of axonal arbors, have been suggested to contribute to eye-specific segregation of retinal ganglion cell inputs. Here, we tested whether BDNF is required for eye-specific segregation of visual inputs to the lateral geniculate nucleus and the superior colliculus, and two other major subcortical target fields in mice. We report that eye-specific patterning is normal in two mutants that lack BDNF expression during the segregation period: a germ-line knockout for BDNF, and a conditional mutant in which BDNF expression is absent or greatly reduced in the central nervous system. We conclude that the availability of BDNF is not necessary for eye-specific segregation in subcortical visual nuclei.
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Affiliation(s)
- Alvin W Lyckman
- The Picower Center for Learning and Memory and the Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA.
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43
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Firth SI, Wang CT, Feller MB. Retinal waves: mechanisms and function in visual system development. Cell Calcium 2005; 37:425-32. [PMID: 15820390 DOI: 10.1016/j.ceca.2005.01.010] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2004] [Accepted: 01/06/2005] [Indexed: 11/23/2022]
Abstract
A characteristic feature of developing neural networks is spontaneous periodic activity. In the developing retina, retinal ganglion cells fire bursts of action potentials that drive large increases in intracellular calcium concentration with a periodicity of minutes. These periodic bursts of action potentials propagate across the developing inner retina as waves, driving neighboring retinal ganglion cells to fire in a correlated fashion. Here we will review recent progress in elucidating the mechanisms in mammals underlying retinal wave propagation and those regulating the periodicity with which these retinal waves occur. In addition, we will review recent experiments indicating that retinal waves are critical for refining retinal projections to their primary targets in the central visual system and may be involved in driving developmental processes within the retina itself.
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Affiliation(s)
- Sally I Firth
- Neurobiology Section, Division of Biological Sciences, Pacific Hall 3127, University of California at San Diego, 9500 Gilman Dr, La Jolla, CA, 92093-0357, USA
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44
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Abstract
One of the seminal discoveries in developmental neuroscience is that altering visual experience through monocular deprivation can alter both the physiological and the anatomical representation of the two eyes, called ocular dominance columns, in primary visual cortex. This rearrangement is restricted to a critical period that starts a few days or weeks after vision is established and ends before adulthood. In contrast to the original hypothesis proposed by Hubel and Wiesel, ocular dominance columns are already substantially formed before the onset of the critical period. Indeed, before the critical period there is a period of ocular dominance column formation during which there is robust spontaneous activity and visual experience. Recent findings raise important questions about whether activity guides ocular dominance column formation in this 'precritical period'. One developmental event that marks the passage from the precritical period to the critical period is the activation of a GABAergic circuit. How these events trigger the transition from the precritical to critical period is not known.
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Affiliation(s)
- Marla B Feller
- Neurobiology Section 0357, UCSD, 9500 Gilman Drive, La Jolla, CA 92093-0357, USA.
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45
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Torborg C, Wang CT, Muir-Robinson G, Feller MB. L-type calcium channel agonist induces correlated depolarizations in mice lacking the beta2 subunit nAChRs. Vision Res 2005; 44:3347-55. [PMID: 15536002 DOI: 10.1016/j.visres.2004.08.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Revised: 07/23/2004] [Indexed: 10/26/2022]
Abstract
Retinal waves are mediated in part by activation of nicotinic receptors containing the beta2 subunit. Mice deficient in beta2 containing nAChRs have maintained firing of action potentials but do not support correlated waves. As a result, beta2-/- mice have inhibited refinement of circuits within the retina as well as retinal projections to the CNS. Previously, we observed that correlated increases in calcium reminiscent of retinal waves could be induced in beta2-/- retina by pharmacological application of the L-type calcium channel agonist, FPL-64176. Here, we characterize FPL-induced activity patterns in beta2-/- retina using both whole cell and multielectrode array recordings. FPL-induced strong depolarizations in previously non-spiking beta2-/- retinal ganglion cells. Though these strong depolarizations were likely to underlie the FPL-induced calcium transients, they led to highly variable effects on the spiking of individual retinal ganglion cells. In addition, induced spiking activity had significantly weaker nearest-neighbor correlations than WT mice. Initial attempts of intraocular injections of FPL in beta2-/- mice did not rescue eye-specific layer formation. These findings indicate that activity induced by FPL is not sufficient for driving eye-specific segregation in beta2-/- mice.
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Affiliation(s)
- Christine Torborg
- Neurobiology Section 0357, Division of Biological Sciences, UCSD, 9500 Gilman Drive, La Jolla, CA 92093-0357, USA
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46
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O'Leary DDM, McLaughlin T. Mechanisms of retinotopic map development: Ephs, ephrins, and spontaneous correlated retinal activity. PROGRESS IN BRAIN RESEARCH 2005; 147:43-65. [PMID: 15581697 DOI: 10.1016/s0079-6123(04)47005-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This chapter summarizes mechanisms that control the development of retinotopic maps in the brain, focusing on work from our laboratory using as models the projection of retinal ganglion cells (RGCs) to the chick optic tectum (OT) or rodent superior colliculus (SC). The formation of a retinotopic map involves the establishment of an initial, very coarse map that subsequently undergoes large-scale remodeling to generate a refined map. All arbors are formed by interstitial branches that form in a topographically biased manner along RGC axons that overshoot their correct termination zone (TZ) along the anterior-posterior (A-P) axis of the OT/SC. The interstitial branches exhibit directed growth along the lateral-medial (L-M) axis of the OT/SC to position the branch at the topographically correct location, where it arborizes to form the TZ. EphA receptors and ephrin-A ligands control in part RGC axon mapping along the A-P axis by inhibiting branching and arborization posterior to the correct TZ. Ephrin-B1 acts bifunctionally through EphB forward signaling to direct branches along the L-M axis of the OT/SC to their topographically correct site. Computational modeling indicates that multiple graded activities are required along each axis to generate a retinotopic map, and makes several predictions, including: the progressive addition of ephrin-As within the OT/SC, due to its expression on RGC axon branches and arbors, is required to increase topographic specificity in branching and arborization as well as eliminate the initial axon overshoot, and that interactions amongst RGC axons that resemble correlated neural activity are required to drive retinotopic refinement. Analyses of mutant mice that lack early spontaneous retinal waves that correlate activity amongst neighboring RGCs, confirm this modeling prediction and show that correlated activity during an early brief critical period is required to drive the large-scale remodeling of the initially topographically coarse projection into a refined one. In summary, multiple graded guidance molecules, retinal waves and correlated spontaneous RGC activity cooperate to generate retinotopic maps.
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Affiliation(s)
- Dennis D M O'Leary
- Molecular Neurobiology Laboratory, The Salk Institute, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Ellsworth CA, Lyckman AW, Feldheim DA, Flanagan JG, Sur M. Ephrin-A2 and -A5 influence patterning of normal and novel retinal projections to the thalamus: Conserved mapping mechanisms in visual and auditory thalamic targets. J Comp Neurol 2005; 488:140-51. [PMID: 15924339 DOI: 10.1002/cne.20602] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Sensory axons are targeted to modality-specific nuclei in the thalamus. Retinal ganglion cell axons project retinotopically to their principal thalamic target, the dorsal lateral geniculate nucleus (LGd), in a pattern likely dictated by the expression of molecular gradients in the LGd. Deafferenting the auditory thalamus induces retinal axons to innervate the medial geniculate nucleus (MGN). These retino-MGN projections also show retinotopic organization. Here we show that ephrin-A2 and -A5, which are expressed in similar gradients in the MGN and LGd, can be used to pattern novel retinal projections in the MGN. As in the LGd, retinal axons from each eye terminate in discrete eye-specific zones in the MGN of rewired wild-type and ephrin-A2/A5 knockout mice. However, ipsilateral eye axons, which arise from retinal regions of high EphA5 receptor expression and represent central visual field, terminate in markedly different ways in the two mice. In rewired wild-type mice, ipsilateral axons specifically avoid areas of high ephrin expression in the MGN. In rewired ephrin knockout mice, ipsilateral projections shift in location and spread more broadly, leading to an expanded representation of the ipsilateral eye in the MGN. Similarly, ipsilateral projections to the LGd in ephrin knockout mice are shifted and are more widespread than in the LGd of wild-type mice. In the MGN, as in the LGd, terminations from the two eyes show little overlap even in the knockout mice, suggesting that local interocular segregation occurs regardless of other patterning determinants. Our data demonstrate that graded topographic labels, such as the ephrins, can serve to shape multiple related aspects of afferent patterning, including topographic mapping and the extent and spread of eye-specific projections. Furthermore, when mapping labels and other cues are expressed in multiple target zones, novel projections are patterned according to rules that operate in their canonical targets.
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Affiliation(s)
- Charlene A Ellsworth
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Torborg CL, Hansen KA, Feller MB. High frequency, synchronized bursting drives eye-specific segregation of retinogeniculate projections. Nat Neurosci 2005; 8:72-8. [PMID: 15608630 PMCID: PMC1463890 DOI: 10.1038/nn1376] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2004] [Accepted: 11/24/2004] [Indexed: 11/09/2022]
Abstract
Blockade of retinal waves prevents the segregation of retinogeniculate afferents into eye-specific layers in the visual thalamus. However, the key features of retinal waves that drive this refinement are controversial. Some manipulations of retinal waves lead to normal eye-specific segregation but others do not. By comparing retinal spiking patterns in several mutant mice with differing levels of eye-specific segregation, we show that the presence of high-frequency bursts synchronized across neighboring retinal ganglion cells correlates with robust eye-specific segregation and that the presence of high levels of asynchronous spikes does not inhibit this segregation. These findings provide a possible resolution to previously described discrepancies regarding the role of retinal waves in retinogeniculate segregation.
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Affiliation(s)
| | - Kristi A. Hansen
- Neurobiology Section, Division of Biological Sciences, UCSD, La Jolla, CA, USA
| | - Marla B. Feller
- Neurobiology Section, Division of Biological Sciences, UCSD, La Jolla, CA, USA
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Plas DT, Visel A, Gonzalez E, She WC, Crair MC. Adenylate Cyclase 1 dependent refinement of retinotopic maps in the mouse. Vision Res 2004; 44:3357-64. [PMID: 15536003 DOI: 10.1016/j.visres.2004.09.036] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2004] [Revised: 09/08/2004] [Indexed: 10/26/2022]
Abstract
Development of the retino-collicular pathway has served as an important model system for examining the cellular mechanisms responsible for the establishment of neuronal maps of the sensory periphery. A consensus has emerged that molecular or chemical cues are responsible for the initial establishment of gross topography in this map, and that activity dependent factors sharpen this initial rough topography into precision. However, there is little evidence available concerning the biochemical signaling mechanisms that are responsible for topographic map refinement in the retino-collicular system. Using a combination of anatomical and biochemical techniques in normal and mutant mice, we provide evidence that Ca2+/Calmodulin regulated Adenylate Cyclase 1 (AC1), which is strongly expressed in the superficial layers of the colliculus, is an important downstream signaling agent for activity dependent map refinement in the superior colliculus.
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Affiliation(s)
- Daniel T Plas
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza S-603, Houston, TX 77030, USA
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Abstract
Neuronal circuits are shaped by experience during critical periods of early postnatal life. The ability to control the timing, duration, and closure of these heightened levels of brain plasticity has recently become experimentally accessible, especially in the developing visual system. This review summarizes our current understanding of known critical periods across several systems and species. It delineates a number of emerging principles: functional competition between inputs, role for electrical activity, structural consolidation, regulation by experience (not simply age), special role for inhibition in the CNS, potent influence of attention and motivation, unique timing and duration, as well as use of distinct molecular mechanisms across brain regions and the potential for reactivation in adulthood. A deeper understanding of critical periods will open new avenues to "nurture the brain"-from international efforts to link brain science and education to improving recovery from injury and devising new strategies for therapy and lifelong learning.
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Affiliation(s)
- Takao K Hensch
- Laboratory for Neuronal Circuit Development, Critical Period Mechanisms Research Group, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
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