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Rajendran Nair DS, Zhu D, Sharma R, Martinez Camarillo JC, Bharti K, Hinton DR, Humayun MS, Thomas BB. Long-Term Transplant Effects of iPSC-RPE Monolayer in Immunodeficient RCS Rats. Cells 2021; 10:cells10112951. [PMID: 34831174 PMCID: PMC8616297 DOI: 10.3390/cells10112951] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/24/2021] [Accepted: 10/25/2021] [Indexed: 12/29/2022] Open
Abstract
Retinal pigment epithelium (RPE) replacement therapy is evolving as a feasible approach to treat age-related macular degeneration (AMD). In many preclinical studies, RPE cells are transplanted as a cell suspension into immunosuppressed animal eyes and transplant effects have been monitored only short-term. We investigated the long-term effects of human Induced pluripotent stem-cell-derived RPE (iPSC-RPE) transplants in an immunodeficient Royal College of Surgeons (RCS) rat model, in which RPE dysfunction led to photoreceptor degeneration. iPSC-RPE cultured as a polarized monolayer on a nanoengineered ultrathin parylene C scaffold was transplanted into the subretinal space of 28-day-old immunodeficient RCS rat pups and evaluated after 1, 4, and 11 months. Assessment at early time points showed good iPSC-RPE survival. The transplants remained as a monolayer, expressed RPE-specific markers, performed phagocytic function, and contributed to vision preservation. At 11-months post-implantation, RPE survival was observed in only 50% of the eyes that were concomitant with vision preservation. Loss of RPE monolayer characteristics at the 11-month time point was associated with peri-membrane fibrosis, immune reaction through the activation of macrophages (CD 68 expression), and the transition of cell fate (expression of mesenchymal markers). The overall study outcome supports the therapeutic potential of RPE grafts despite the loss of some transplant benefits during long-term observations.
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Affiliation(s)
- Deepthi S. Rajendran Nair
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.S.R.N.); (J.C.M.C.); (M.S.H.)
| | - Danhong Zhu
- Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.Z.); (D.R.H.)
| | - Ruchi Sharma
- Unit on Ocular and Stem Cell Translational Research, National Eye Institute, NIH, Bethesda, MD 20892, USA; (R.S.); (K.B.)
| | - Juan Carlos Martinez Camarillo
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.S.R.N.); (J.C.M.C.); (M.S.H.)
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Kapil Bharti
- Unit on Ocular and Stem Cell Translational Research, National Eye Institute, NIH, Bethesda, MD 20892, USA; (R.S.); (K.B.)
| | - David R. Hinton
- Department of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.Z.); (D.R.H.)
| | - Mark S. Humayun
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.S.R.N.); (J.C.M.C.); (M.S.H.)
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Biju B. Thomas
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; (D.S.R.N.); (J.C.M.C.); (M.S.H.)
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
- Correspondence: ; Tel.: +1-323-442-5593
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Moore NS, Mans RA, McCauley MK, Allgood CS, Barksdale KA. Critical Effects on Akt Signaling in Adult Zebrafish Brain Following Alterations in Light Exposure. Cells 2021; 10:cells10030637. [PMID: 33809219 PMCID: PMC8000057 DOI: 10.3390/cells10030637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 11/16/2022] Open
Abstract
Evidence from human and animal studies indicate that disrupted light cycles leads to alterations of the sleep state, poor cognition, and the risk of developing neuroinflammatory and generalized health disorders. Zebrafish exhibit a diurnal circadian rhythm and are an increasingly popular model in studies of neurophysiology and neuropathophysiology. Here, we investigate the effect of alterations in light cycle on the adult zebrafish brain: we measured the effect of altered, unpredictable light exposure in adult zebrafish telencephalon, homologous to mammalian hippocampus, and the optic tectum, a significant visual processing center with extensive telencephalon connections. The expression of heat shock protein-70 (HSP70), an important cell stress mediator, was significantly decreased in optic tectum of adult zebrafish brain following four days of altered light exposure. Further, pSer473-Akt (protein kinase B) was significantly reduced in telencephalon following light cycle alteration, and pSer9-GSK3β (glycogen synthase kinase-3β) was significantly reduced in both the telencephalon and optic tectum of light-altered fish. Animals exposed to five minutes of environmental enrichment showed significant increase in pSer473Akt, which was significantly attenuated by four days of altered light exposure. These data show for the first time that unpredictable light exposure alters HSP70 expression and dysregulates Akt-GSK3β signaling in the adult zebrafish brain.
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Garina NS. [Tectal Evoked Potentials during Retinal Baclofen Application in the Carp]. Zh Vyssh Nerv Deiat Im I P Pavlova 2016; 66:626-631. [PMID: 30695407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Changes of primary visual center evoked potentials in response to white light and optic nerve electric stimulation were investigated during retinal GABAb-receptors activation with baclofen in dark-adapted carp. It was found, that baclofen - induced b-wave ERG decreasing, was accompanied by a significant amplitude growing as in the evoked potential to light as in the evoked potential to electric nerve stimulation: It is proposed, that light evoked potential changes reflect the increasing of the third retinal neuron responses to light and/or tectal neuron responsiveness enhancement.
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Rea AC, Vandenberg LN, Ball RE, Snouffer AA, Hudson AG, Zhu Y, McLain DE, Johnston LL, Lauderdale JD, Levin M, Dore TM. Light-activated serotonin for exploring its action in biological systems. ACTA ACUST UNITED AC 2013; 20:1536-46. [PMID: 24333002 DOI: 10.1016/j.chembiol.2013.11.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 10/29/2013] [Accepted: 11/01/2013] [Indexed: 11/17/2022]
Abstract
Serotonin (5-HT) is a neuromodulator involved in regulating mood, appetite, memory, learning, pain, and establishment of left-right (LR) asymmetry in embryonic development. To explore the role of 5-HT in physiology, we have created two forms of "caged" 5-HT, BHQ-O-5HT and BHQ-N-5HT. When exposed to 365 or 740 nm light, BHQ-O-5HT releases 5-HT through one- or two-photon excitation, respectively. BHQ-O-5HT mediated changes in neural activity in cultured mouse primary sensory neurons and the trigeminal ganglion and optic tectum of intact zebrafish larvae in the form of high-amplitude spiking in response to light. In Xenopus laevis embryos, light-activated 5-HT increased the occurrence of LR patterning defects. Maximal rates of LR defects were observed when 5-HT was released at stage 5 compared with stage 8. These experiments show the potential for BHQ-caged serotonins in studying 5-HT-regulated physiological processes.
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Affiliation(s)
- Adam C Rea
- Department of Chemistry, University of Georgia, Athens, GA 30602, USA
| | - Laura N Vandenberg
- Biology Department and Tufts Center for Regenerative and Developmental Biology, Tufts University, Suite 4600, 200 Boston Avenue, Medford, MA 02155-4243, USA
| | - Rebecca E Ball
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Ashley A Snouffer
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Alicia G Hudson
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Yue Zhu
- Department of Chemistry, University of Georgia, Athens, GA 30602, USA
| | - Duncan E McLain
- Department of Chemistry, University of Georgia, Athens, GA 30602, USA; New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | | | - James D Lauderdale
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Michael Levin
- Biology Department and Tufts Center for Regenerative and Developmental Biology, Tufts University, Suite 4600, 200 Boston Avenue, Medford, MA 02155-4243, USA
| | - Timothy M Dore
- Department of Chemistry, University of Georgia, Athens, GA 30602, USA; New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates.
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Yasuda T, Oda S, Ishikawa Y, Watanabe-Asaka T, Hidaka M, Yasuda H, Anzai K, Mitani H. Live imaging of radiation-induced apoptosis by yolk injection of Acridine Orange in the developing optic tectum of medaka. J Radiat Res 2009; 50:487-494. [PMID: 19680012 DOI: 10.1269/jrr.09043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
To observe the sequential radiation-induced apoptosis in a living embryo, we injected Acridine Orange (AO) solution into the yolk of embryo and visualized radiation-induced apoptosis in developing optic tectum (OT). Medaka embryos at stage 28, when neural cells proliferate rapidly in the OT, were irradiated with 5 Gy X-rays which is a non-lethal dose for irradiated embryos at hatching. The irradiated embryos hatched normally without morphological abnormalities in their brains, even though a large number of apoptotic cells were induced transiently in OT. By yolk injection, apoptotic cells in OT were distinguished as AO-positive small nuclei at 3 h after irradiation. At 8-10 h after irradiation, AO-positive rosette-shaped clusters were obviously distinguished in marginal tectal regions of OT where cells are proliferating intensely. The AO-positive clusters became bigger and more obvious, but the number did not increase up to 24 h after irradiation and completely disappeared up to 49 h after irradiation. This characteristic appearance of the AO-positive nuclei/clusters is in good agreement with our previous results, based on the examination of fixed specimens stained with AO by injection into the peri-vitelline space, suggesting that the AO-yolk injection method is highly reliable for detecting apoptotic cells in living embryos. The live imaging of apoptotic cells in developing Medaka embryos by AO-yolk injection method is expected to reveal more of the details of the dynamics of apoptotic responses in the irradiated brain and other tissues.
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Affiliation(s)
- Takako Yasuda
- Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan.
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Drouyer E, Dkhissi-Benyahya O, Chiquet C, WoldeMussie E, Ruiz G, Wheeler LA, Denis P, Cooper HM. Glaucoma alters the circadian timing system. PLoS One 2008; 3:e3931. [PMID: 19079596 PMCID: PMC2592693 DOI: 10.1371/journal.pone.0003931] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Accepted: 11/17/2008] [Indexed: 11/18/2022] Open
Abstract
Glaucoma is a widespread ocular disease and major cause of blindness characterized by progressive, irreversible damage of the optic nerve. Although the degenerative loss of retinal ganglion cells (RGC) and visual deficits associated with glaucoma have been extensively studied, we hypothesize that glaucoma will also lead to alteration of the circadian timing system. Circadian and non-visual responses to light are mediated by a specialized subset of melanopsin expressing RGCs that provide photic input to mammalian endogenous clock in the suprachiasmatic nucleus (SCN). In order to explore the molecular, anatomical and functional consequences of glaucoma we used a rodent model of chronic ocular hypertension, a primary causal factor of the pathology. Quantitative analysis of retinal projections using sensitive anterograde tracing demonstrates a significant reduction (approximately 50-70%) of RGC axon terminals in all visual and non-visual structures and notably in the SCN. The capacity of glaucomatous rats to entrain to light was challenged by exposure to successive shifts of the light dark (LD) cycle associated with step-wise decreases in light intensity. Although glaucomatous rats are able to entrain their locomotor activity to the LD cycle at all light levels, they require more time to re-adjust to a shifted LD cycle and show significantly greater variability in activity onsets in comparison with normal rats. Quantitative PCR reveals the novel finding that melanopsin as well as rod and cone opsin mRNAs are significantly reduced in glaucomatous retinas. Our findings demonstrate that glaucoma impacts on all these aspects of the circadian timing system. In light of these results, the classical view of glaucoma as pathology unique to the visual system should be extended to include anatomical and functional alterations of the circadian timing system.
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Affiliation(s)
- Elise Drouyer
- Department of Chronobiology, INSERM, U846, Stem Cell and Brain Research Institute, Bron, France
- University of Lyon, Lyon I, UMR-S 846, Lyon, France
| | - Ouria Dkhissi-Benyahya
- Department of Chronobiology, INSERM, U846, Stem Cell and Brain Research Institute, Bron, France
- University of Lyon, Lyon I, UMR-S 846, Lyon, France
| | - Christophe Chiquet
- Department of Chronobiology, INSERM, U846, Stem Cell and Brain Research Institute, Bron, France
- Department of Ophthalmology, CHU de Grenoble, Faculté de Médecine, Université Joseph Fourier, Grenoble, France
| | | | - Guadalupe Ruiz
- Allergan Inc., Irvine, California, United States of America
| | | | - Philippe Denis
- Department of Chronobiology, INSERM, U846, Stem Cell and Brain Research Institute, Bron, France
- Department of Ophthalmology, CHU de Lyon Hopital Edouard Herriot, Lyon, France
| | - Howard M. Cooper
- Department of Chronobiology, INSERM, U846, Stem Cell and Brain Research Institute, Bron, France
- University of Lyon, Lyon I, UMR-S 846, Lyon, France
- Centre National de la Recherche Scientifique, Lyon, France
- * E-mail:
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de Almeida LP, Ramos PL, Pandossio JE, Landeira-Fernandez J, Zangrossi H, Nogueira RL. Prior electrical stimulation of dorsal periaqueductal grey matter or deep layers of the superior colliculus sensitizes rats to anxiety-like behaviors in the elevated T-maze test. Behav Brain Res 2006; 170:175-81. [PMID: 16569447 DOI: 10.1016/j.bbr.2006.02.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Revised: 02/06/2006] [Accepted: 02/16/2006] [Indexed: 11/23/2022]
Abstract
Electrical stimulation of the dorsal periaqueductal grey matter (DPAG) and deep layers of the superior colliculus (DLSC) of the rat elicits anxiety-like reactions such as freezing and flight. The temporal course of the effects of the aversive electrical stimulation of the DPAG (5, 15 and 30 min afterward) and DLSC (5, 10 and 15 min afterward) on the defensive response of rats exposed to elevated T-maze were determined. The elevated T-maze generates two defensive behaviors, inhibitory avoidance and one-way escape, which have been related, respectively, to generalized anxiety and panic disorders. Prior electrical stimulation of the DPAG (15 min) and DLSC (5 min) enhanced inhibitory avoidance when compared to no-operated and sham animals, although not affecting escape. Therefore, stimulation of the DPAG and DLSC causes a heightened responsivity to anxiogenic stimulus, but not to panicogenic stimulus, inherent to elevated T-maze. These findings support the participation of the DPAG and DLSC in the elaboration of adaptive responses to stressful situations. Besides, the data supports the view that prior electrical stimulation of DPAG and DLSC is selective in sensitizing rats to anxiety-like behaviors, but not to panic-like behaviors in the elevated T-maze test.
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Affiliation(s)
- Leandro Pinto de Almeida
- Laboratory of Comparative Psychology, School of Psychology, University Estácio de Sá, 20260-060 Rio de Janeiro, RJ, Brazil
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Funke S, Ewert JP. Neuropeptide Y suppresses glucose utilization in the dorsal optic tectum towards visual stimulation in the toad Bombina orientalis: A [14C]2DG study. Neurosci Lett 2006; 392:43-6. [PMID: 16209904 DOI: 10.1016/j.neulet.2005.09.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2005] [Revised: 08/19/2005] [Accepted: 09/02/2005] [Indexed: 11/21/2022]
Abstract
Neuropeptide Y (NPY) experimentally administered to the surface of the optic tectum in visually stimulated fire bellied toads diminishes local glucose utilization in the retinorecipient tectal laminae. Strong NPY-induced suppression of tectal glucose utilization was found even when visual retinal input to the tectum was boosted pharmacologically under systemic apomorphine treatment. These novel results on the local cerebral energy metabolism contribute to the concept that NPY controls retinotectal visual processing via an inhibitory mechanism.
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Affiliation(s)
- Simone Funke
- Department of Neurobiology, Faculty of Natural Sciences, University of Kassel, Germany
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Coizet V, Dommett EJ, Redgrave P, Overton PG. Nociceptive responses of midbrain dopaminergic neurones are modulated by the superior colliculus in the rat. Neuroscience 2006; 139:1479-93. [PMID: 16516396 DOI: 10.1016/j.neuroscience.2006.01.030] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 01/19/2006] [Accepted: 01/26/2006] [Indexed: 11/25/2022]
Abstract
Midbrain dopaminergic neurones exhibit a short-latency phasic response to unexpected, biologically salient stimuli. In the rat, the superior colliculus is critical for relaying short-latency visual information to dopaminergic neurones. Since both collicular and dopaminergic neurones are also responsive to noxious stimuli, we examined whether the superior colliculus plays a more general role in the transmission of short-latency sensory information to the ventral midbrain. We therefore tested whether the superior colliculus is a critical relay for nociceptive input to midbrain dopaminergic neurones. Simultaneous recordings were made from collicular and dopaminergic neurones in the anesthetized rat, during the application of noxious stimuli (footshock). Most collicular neurones exhibited a short-latency, short duration excitation to footshock. The majority of dopaminergic neurones (92/110; 84%) also showed a short-latency phasic response to the stimulus. Of these, 79/92 (86%) responded with an initial inhibition and the remaining 14/92 (14%) responded with an excitation. Response latencies of dopaminergic neurones were reliably longer than those of collicular neurones. Tonic suppression of collicular activity by an intracollicular injection of the local anesthetic lidocaine reduced the latency, increased the duration but reduced the magnitude of the phasic inhibitory dopaminergic response. These changes were accompanied by a decrease in the baseline firing rate of dopaminergic neurones. Activation of the superior colliculus by the local injections of the GABA(A) antagonist bicuculline also reduced the latency of inhibitory nociceptive responses of dopaminergic neurones, which was accompanied by an increased in baseline dopaminergic firing. Aspiration of the ipsilateral superior colliculus failed to alter the nociceptive response characteristics of dopaminergic neurones although fewer nociceptive neurones were encountered after the lesions. Together these results suggest that the superior colliculus can modulate both the baseline activity of dopaminergic neurones and their phasic responses to noxious events. However, the superior colliculus is unlikely to be the primary source of nociceptive sensory input to the ventral midbrain.
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Affiliation(s)
- V Coizet
- Department of Psychology, University of Sheffield, UK.
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Manns M, Güntürkün O, Heumann R, Blöchl A. Photic inhibition of TrkB/Ras activity in the pigeon's tectum during development: impact on brain asymmetry formation. Eur J Neurosci 2005; 22:2180-6. [PMID: 16262656 DOI: 10.1111/j.1460-9568.2005.04410.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Asymmetric photic stimulation during embryonic or post-hatch development induces a functional lateralization of the pigeon's visual system, which is accompanied by left-right differences in tectal cell sizes. The intracellular membrane-anchored GTPase Ras can be activated by a number of upstream mechanisms including binding of brain-derived neurotrophic factor to its specific TrkB receptor. Ras activity plays an important morphogenetic role in neurons and therefore might also be involved in the asymmetric differentiation of tectal cells. To investigate the role of Ras, we determined the relative levels of activated Ras and of signalling active phospho-TrkB in tecta of light- and dark-incubated pigeons and combined this with an immunohistochemical detection of Ras-GTP and TrkB receptors. While Ras activation levels did not differ between light- and dark-incubated pigeons during embryonic development, directly after hatching Ras activity was significantly decreased in the stronger stimulated left tectum of light-incubated animals. This was accompanied by lower levels of TrkB phosphorylation. Immunohistochemical staining revealed Ras-GTP-positive cell bodies within the efferent cell layer. These cells were TrkB-positive and developed enlarged soma sizes within the right tectum during the first week after hatching. This association suggests asymmetric Ras activation to be involved in the asymmetric differentiation of the efferent cells as a result of asymmetric TrkB signalling. Because asymmetric light exposure occurs only during embryonic development, the observed transient asymmetric inhibition of TrkB/Ras activity after hatching may reflect differential embryonic maturation of tectal inhibitory circuits leading to a functional superiority of the right eye in the adult organism.
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Affiliation(s)
- Martina Manns
- Biopsychologie, Institut für Kognitive Neurowissenschaft, Fakultät für Psychologie, Ruhr-Universität-Bochum, 44780 Bochum, Germany.
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Giraldi-Guimarães A, Mendez-Otero R. Induction of the candidate-plasticity NGFI-A protein in the adult rat superior colliculus after visual stimulation. ACTA ACUST UNITED AC 2005; 133:242-52. [PMID: 15710241 DOI: 10.1016/j.molbrainres.2004.10.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2004] [Indexed: 11/18/2022]
Abstract
In this work, we studied the visually driven expression of the plasticity-related transcription factor NFGI-A in the superficial layers of the rat superior colliculus (sSC) using immunohistochemistry. After dark adaptation, NGFI-A expression was completely down-regulated, indicating this protein is not constitutively expressed in the sSC. Light stimulation for 10 min after dark adaptation was insufficient to induce detectable levels of this protein. But after 30 min of light stimulation, few NGFI-A+ cells were observed in the superficial layers, indicating that the minimal time of stimulation that is sufficient to induce this protein is sometime between 10 and 30 min. The number of NGFI-A+ cells increased progressively, reaching a peak after 90 min. This peak is not reached if animals are returned to darkness after 30 min of stimulation, when a presumable peak in NGFI-A mRNA is reached. Light stimulation of animals in which the retinocollicular or corticocollicular projections were removed revealed that NGFI-A expression is mainly driven by retinal contralateral projections. Removal of corticocollicular projections did not cause any change in the NGFI-A expression in the ipsilateral sSC, in relation to the contralateral (control) sSC, suggesting that this pathway has a minor influence. Our results showed that NGFI-A protein expression in the sSC is entirely dependent on visual stimulation and suggests that the sSC visual circuitry is an interesting model for studies about the involvement of this transcription factor in synaptic plasticity.
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Affiliation(s)
- Arthur Giraldi-Guimarães
- Laboratório de Neurobiologia Celular e Molecular, Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ, 21949-900, Brazil.
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Du JL, Poo MM. Rapid BDNF-induced retrograde synaptic modification in a developing retinotectal system. Nature 2004; 429:878-83. [PMID: 15215865 DOI: 10.1038/nature02618] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2003] [Accepted: 05/07/2004] [Indexed: 01/19/2023]
Abstract
In cultures of hippocampal neurons, induction of long-term synaptic potentiation or depression by repetitive synaptic activity is accompanied by a retrograde spread of potentiation or depression, respectively, from the site of induction at the axonal outputs to the input synapses on the dendrites of the presynaptic neuron. We report here that rapid retrograde synaptic modification also exists in an intact developing retinotectal system. Local application of brain-derived neurotrophic factor (BDNF) to the Xenopus laevis optic tectum, which induced persistent potentiation of retinotectal synapses, led to a rapid modification of synaptic inputs at the dendrites of retinal ganglion cells (RGCs), as shown by a persistent enhancement of light-evoked excitatory synaptic currents and spiking activity of RGCs. This retrograde effect required TrkB receptor activation, phospholipase Cgamma activity and Ca2+ elevation in RGCs, and was accounted for by a selective increase in the number of postsynaptic AMPA-subtype glutamate receptors at RGC dendrites. Such retrograde information flow in the neuron allows rapid regulation of synaptic inputs at the dendrite in accordance to signals received at axon terminals, a process reminiscent of back-propagation algorithm for learning in neural networks.
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Affiliation(s)
- Jiu-Lin Du
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720, USA
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13
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Thomas BB, Seiler MJ, Sadda SR, Aramant RB. Superior colliculus responses to light – preserved by transplantation in a slow degeneration rat model. Exp Eye Res 2004; 79:29-39. [PMID: 15183098 DOI: 10.1016/j.exer.2004.02.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Accepted: 02/24/2004] [Indexed: 12/01/2022]
Abstract
PURPOSE To determine whether retinal transplantation can preserve visual responses in the superior colliculus (SC) of the S334ter-line-5 rat, a transgenic model for slow photoreceptor degeneration, which is more similar to human retinitis pigmentosa than the fast degeneration line 3 S334ter rat. METHODS Visual responses to a light flash were recorded in the SC. Rats that had received embryonic day (E) 19-20 fetal retinal sheet transplants at the age of 26-30 days were tested at the ages of 200-254 days. Controls were age-matched rats without surgery and with sham surgery. As a baseline, in no-surgery line-5 rats, the temporal pattern of visual sensitivity loss was evaluated electrophysiologically in the SC from 60 days up to one year of age. RESULTS In untreated S334ter-line-5 rats, decline in visual sensitivity in the SC was parallel to the photoreceptor loss. At 109 day of age, a relative scotoma developed in the area of the SC corresponding to the nasal retinal region. At 200-254 days of age, the majority of the SC was devoid of any light-driven responses. In contrast, at this time point, transplanted rats with 'good' retinal grafts with normal lamination had visual responses in the caudal region of the SC, the area corresponding topographically to the transplant location in the retina. In these rats, the various parameters of SC responses such as the latency of the onset of the visual response, the response peak amplitude and the consistency of the visual response were significantly different from the control groups (no-surgery, sham surgery, 'poor' transplants) and were more comparable to normal albino rats, however, with a slightly longer latency (70-90 vs. 30-50 msec). CONCLUSIONS Fetal retinal sheet transplantation showed a long-term rescue effect on visual function in this animal model of slow photoreceptor degeneration.
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Affiliation(s)
- Biju B Thomas
- Department of Ophthalmology, Doheny Eye Institute, University of Southern California, 1450 San Pablo St, Los Angeles, CA 90033, USA
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14
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Abstract
A pathway from the superficial visual layers to the intermediate premotor layers of the superior colliculus has been proposed to mediate visually guided orienting movements. In these experiments, we combined photostimulation using "caged" glutamate with in vitro whole cell patch-clamp recording to demonstrate this pathway in the rat. Photostimulation in the superficial gray and optic layers (SGS and SO, respectively) evoked synaptic responses in intermediate gray layer (SGI) cells. The responses comprised individual excitatory postsynaptic currents (EPSCs) or EPSC clusters. Blockade of these EPSCs by TTX confirmed that they were synaptically mediated. Stimulation within a column (approximately 500 microm diam) extending superficially from the recorded cell evoked the largest and most reliable responses, but off-axis stimuli were effective as well. The EPSCs could be evoked by stimuli 1,000 microm off-axis from the postsynaptic neuron. The dimensions of this wider region (approximately 2 mm diam) corresponded to those of the dendrites of superficial layer wide-field neurons. SGI neurons differed in their input from SGS and SO; neurons in the middle of the intermediate layer (SGIb) were less likely to respond to visual layer photostimulation than were those in sublayers just above and below them. However, focal stimulation within SGIa did evoke responses within SGIb, indicating that SGIb neurons may receive input from the visual layers indirectly. These results demonstrate a columnar pathway that may mediate visually guided orienting movements, but the results also reveal spatial attributes of the pathway which imply that it also plays a more complex role in visuomotor integration.
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Affiliation(s)
- Matthew C Helms
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710, USA
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15
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Suzuki S, Suzuki Y, Ohtsuka K. Convergence eye movements evoked by microstimulation of the rostral superior colliculus in the cat. Neurosci Res 2004; 49:39-45. [PMID: 15099702 DOI: 10.1016/j.neures.2004.01.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2003] [Accepted: 01/20/2004] [Indexed: 11/28/2022]
Abstract
Results of our previous studies suggest that the circumscribed area in the rostral superior colliculus (SC) of the cat is involved in the control of accommodation. Accommodation is closely linked with vergence eye movements. In this study, we investigated whether or not vergence eye movements are evoked by microstimulation of the rostral SC in the cat. In addition, we studied the effect of chemical inhibition of the rostral SC on visually guided vergence eye movements. This study was conducted on three cats, weighing 2.5-3.5 kg. The animals were trained to carry out visually guided saccade and convergence tasks. Eye movements were measured using search coils placed on both eyes. We recorded eye movements evoked by microstimulation of the rostral SC in the alert cats. Muscimol was injected into the rostral SC, and the effect of SC inactivation on visually guided vergence eye movements was investigated. Convergence eye movements were evoked by low-current stimulation (< 30 microA) of a circumscribed area in the intermediate layers of the rostral SC on one side. Spontaneous saccades were interrupted by the stimulation of the low-threshold area for evoking convergence. Visually guided convergence eye movements were severely diminished by the injection of muscimol into the low-threshold area for evoking convergence of the SC. The rostral SC is related to the control of vergence eye movements as well as accommodation. The rostral SC may be involved in the functional linkage between accommodation, convergence and visual fixation.
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Affiliation(s)
- Shunichi Suzuki
- Department of Ophthalmology, School of Medicine, Sapporo Medical University, S-1, W-16, Chuo-ku, Sapporo 060-8543, Japan.
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16
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Abstract
We investigated the influence of modulating NO synthesis on oscillatory components of ON and OFF evoked field potentials in developing rat superior colliculus. Nitric oxide (NO) is involved in neuronal transmission by adjusting neurotransmitter release in adults and in stabilizing synaptic connections in developing brains. NO synthesis was decreased by inhibiting nitric oxide synthase (NOS) with an acute microinjection of N-nitro-L-arginine methyl ester (L-NAME); whereas NO synthesis was augmented by an acute microinjection of L-arginine (L-ARG). The study is focused on rhythmic activity by analyzing fast Fourier transform (FFT). Collicular responses were recorded in anesthetized rats, at post-natal days (PND) 13-19 and adults. This time window was chosen because it is centered on eye opening. NO down- and upregulation resulted in a dual effect depending on age and response-type. NO synthesis inhibition decreased the magnitude of oscillations in ON responses in the youngest animals (PND13-PND14), whereas oscillations of frequencies higher than 20 Hz in OFF responses were increased in all age groups of developing rats. In adults NO downregulation increased oscillations in ON responses and decreased oscillations in OFF responses. L-arginine application produced effects opposite to those seen with L-NAME. Our data together with results reported in the literature suggest that the temporal patterns of the evoked activity are NO-dependent. This sculpting action of the evoked firing may play a role in the synchronization of action potentials in afferent axons which in turn contributes to synaptic stabilization.
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Affiliation(s)
- S Molotchnikoff
- Département des Sciences Biologiques, Université de Montréal, CP 6128 Succ centre-ville Montréal, PQ, Canada H3C 3J7.
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Dunlop SA, Tee LBG, Stirling RV, Taylor AL, Runham PB, Barber AB, Kuchling G, Rodger J, Roberts JD, Harvey AR, Beazley LD. Failure to restore vision after optic nerve regeneration in reptiles: Interspecies variation in response to axotomy. J Comp Neurol 2004; 478:292-305. [PMID: 15368531 DOI: 10.1002/cne.20299] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Optic nerve regeneration within the reptiles is variable. In a snake, Viper aspis, and the lizard Gallotia galloti, regeneration is slow, although some retinal ganglion cell (RGC) axons eventually reach the visual centers (Rio et al. [1989] Brain Res 479:151-156; Lang et al. [1998] Glia 23:61-74). By contrast, in a lizard, Ctenophorus ornatus, numerous RGC axons regenerate rapidly to the visual centers, but unless animals are stimulated visually, the regenerated projection lacks topography and animals remain blind via the experimental eye (Beazley et al. [2003] J. Neurotrauma 20:1263-1269). V. aspis, G. galloti, and C. ornatus belong respectively to the Serpentes, Lacertidae, and Agamidae within the Eureptilia, the major modern group of living reptiles comprising the Squamata (snakes, lizards, and geckos) and the Crocodyllia. Here we have extended the findings on Eureptilia to include two geckos (Gekkonidae), Cehyra variegata and Nephrurus stellatus. We also examined a turtle, Chelodina oblonga, the Testudines being the sole surviving representatives of the Parareptilia, the more ancient reptilian group. In all three species, visually elicited behavioral responses were absent throughout regeneration, a result supported electrophysiologically; axonal tracing revealed that only a small proportion of RGC axons crossed the lesion and none entered the contralateral optic tract. RGC axons failed to reach the chiasm in C. oblonga, and in G. variegata, and N. stellatus RGC axons entered the opposite optic nerve; a limited ipsilateral projection was seen in G. variegata. Our results support a heterogeneous response to axotomy within the reptiles, each of which is nevertheless dysfunctional.
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Affiliation(s)
- Sarah A Dunlop
- School of Animal Biology, The University of Western Australia, Crawley 6009, Australia.
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18
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Abstract
OBJECT The authors report a consecutive series of 10 patients who presented with signs and symptoms caused by tectal tumors. Clinical findings, radiographic features, neuroendoscopic management strategies, and histological findings are reported and discussed. METHODS Since January 1990, 11 neuroendoscopic procedures were performed in 10 patients who harbored tectal tumors. The patients were followed for an average of 5 years (range 2 months-11 years), and a retrospective study was conducted in which case notes, radiological findings, operative notes, and histopathological findings were assessed. Magnetic resonance (MR) imaging was performed, and the images were used to classify patients into three groups: those with hypertrophy of the tectum in whom isointensity appeared on T1-weighted images (Group 1); those with a tectal tumor occupying the cerebral aqueduct in whom decreased signal intensity appeared on T1-weighted images, as well as no enhancement after gadolinium administration (Group 2); and those with a tectal tumor in whom mixed signal intensity and conspicuous evidence of contrast enhancement appeared on T1-weighted images (Group 3). The results of histological examination were consistent with MR imaging features: in Group 1, glial tissue or gliosis; in Group 2, benign astrocytoma; and in Group 3, malignant astrocytoma. Cerebrospinal fluid diversion was the only surgical treatment that provided relief from obstructive hydrocephalus. One patient in Group 3 underwent radiotherapy and subsequent partial tumor removal under neuroendoscopic guidance. Thereafter, the tumor remained in decline. All patients had normal intellectual status after undergoing surgery in which a neuroendoscope was used. CONCLUSIONS Neuroendoscopic procedures can provide histological diagnosis, define the tumor-midbrain interrelationship, and be highly effective in treating obstructive hydrocephalus and in removing tectal tumors. This procedure may receive clinical application as a new management strategy for tectal glioma.
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Affiliation(s)
- K Oka
- Department of Neurosurgery, Fukuoka University School of Medicine, Japan.
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19
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Abstract
The spatiotemporal patterns of excitatory synaptic activity in response to diffuse lightON and OFF stimuli were examined by means of current source density (CSD) analysis. The qualitative and quantitative analyses obtained from 24 depth profiles for each stimulus revealed obviously different distributions of synaptic activity in the laminar structure. Two or three dominant current sinks I, II, and III were evoked in response to diffuse light ON stimulation. Sink I was observed at the bottom of the retinorecipient layer. Both sinks II and III, showing an identical spatial pattern, were observed just above sink I. On the other hand, diffuse light OFF stimulation elicited up to six current sinks IV, V, VI, VII, VIII, and IX. Sink IV was observed at the bottom of the retinorecipient layer. Sink V was observed in the most superficial layer. Both sinks VI and VIII were located between the two preceding sinks. Finally, sinks VII and IX occurred below the retinorecipient layer. Five electrically evoked current sinks A, B, C, D, and E, characterized in our previous study, were also recognized in the present quantitative analysis. A statistical analysis revealed that, in visually evoked responses, statistical differences in the spatial distribution were not present between sinks I and IV, and sinks II and VIII (P < 0.05). The analysis also showed that, in electrically evoked responses, only a pair of sinks C and E exhibit virtually identical spatial distribution (P < 0.05). Based on well-known properties of the retinal ganglion cells, possible neuronal mechanisms underlying each of current sinks in the ON and OFF channels and their functional meanings were considered. Sink I reflects the excitatory monosynaptic activity derived from R3 retinal ganglion cells. Sink IV reflects the excitatory monosynaptic activity derived from both R3 and R4 cells. Sinks V, VI, VII, and IX may be composed of successive polysynaptic excitatory potentials derived from convergence of inputs from both R3 and R4 cells. We concluded that the early four sinks play in particular an important role in eliciting avoidance behavior. On the other hand, sinks II, III, and VIII reflect excitatory synaptic activities derived from - retinal fibers of another type having slow conduction velocity. These late current sinks were suggested to mediate prey catching and its facilitation.
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Affiliation(s)
- H Nakagawa
- Department of Biochemical Engineering and Science, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, Iizuka, Fukuoka 820, Japan
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20
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Yamada T, Kobayashi T, Okada Y. The effects of simulated ischemia on the levels of adenosine and its metabolites in slices of cerebellum, superior colliculus and hippocampus in the guinea pig-in vitro study. Brain Res 1998; 787:220-5. [PMID: 9518623 DOI: 10.1016/s0006-8993(97)01482-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The purpose of this present study is to clarify adenosine (ADO) metabolism in guinea pig brain slices during simulated ischemia. In slice preparations after decapitation, ADO levels were lowest in slices of the cerebellum (1.2 nmol/mg protein), followed by the superior colliculus (3.4) and highest in the hippocampus (6.4), and the combined concentrations of inosine (Ino) and hypoxanthine (HX) were highest in the cerebellum (5.5), followed by the superior colliculus (3.5) and the hippocampus (1.5). After preincubation with standard medium with oxygen and glucose for 30 min, total ADO levels (tissue ADO plus ADO lost into medium during incubation) decreased to 0.3 in the cerebellum, to 1.3 in the superior colliculus and to 2. 9 in the hippocampus. On the other hand, levels of total Ino and HX increased to 21.1 in the cerebellum, to 14.3 in the hippocampus and to 12.0 in the superior colliculus. To investigate the effect of simulated ischemia on ADO metabolism, preincubated slices were exposed for 10 min in medium deprived of oxygen and glucose. The increases of ADO content after 10 min ischemia were 0.2 in the cerebellum, 1.0 in the superior colliculus and 1.3 in the hippocampus. In contrast, the increases of both Ino and HX concentrations were 2.9 in the cerebellum, 2.2 in the superior colliculus and 1.4 in the hippocampus. The total amount of the increase in ADO, Ino and HX was approximately 3 in all three regions. These results indicate that there are significant differences in the metabolic rate to degrade ADO into Ino and HX in various areas of brain possibly due to differences in adenosine deaminase activity in those areas.
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Affiliation(s)
- T Yamada
- Department of Physiology, Kobe University School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650, Japan
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21
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Karlsson M, Hallböök F. Kainic acid, tetrodotoxin and light modulate expression of brain-derived neurotrophic factor in developing avian retinal ganglion cells and their tectal target. Neuroscience 1998; 83:137-50. [PMID: 9466404 DOI: 10.1016/s0306-4522(97)00340-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Increasing evidence underlies the importance of neurotrophins as neuron-derived trophic signals in the developing visual system, although their precise roles are still undefined. Here we show that brain-derived neurotrophic factor messenger RNA is simultaneously expressed in a subpopulation of retinal ganglion cells and in their target during late embryogenesis. Moreover, light as well as the excitotoxin; kainic acid, induced an increase of the brain-derived neurotrophic factor messenger RNA, which could be blocked by the sodium-channel blocker; tetrodotoxin. Messenger RNA for trkB, a receptor for brain-derived neurotrophic factor, was found in the retinal ganglion cells expressing brain-derived neurotrophic factor showing that certain retinal ganglion cells express messenger RNA both for brain-derived neurotrophic factor and trkB. Furthermore, trkB messenger RNA was found in tectum, in the same layers as the brain-derived neurotrophic factor messenger RNA. These findings suggest that brain-derived neurotrophic factor expression is regulated in an activity-dependent manner during the phase of development when neuronal activity plays an important role.
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Affiliation(s)
- M Karlsson
- Department of Developmental Neuroscience, BMC, Uppsala University, Sweden
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22
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Sauvé Y, Sawai H, Rasminsky M. Functional synaptic connections made by regenerated retinal ganglion cell axons in the superior colliculus of adult hamsters. J Neurosci 1995; 15:665-75. [PMID: 7823170 PMCID: PMC6578284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Regenerated synaptic connections in the damaged mammalian visual system were studied in adult hamsters in which retinal ganglion cells (RGCs) regrew their axons through autologous peripheral nerve grafts directed from the stump of the transected optic nerve to the superior colliculus (SC). Unitary responses to illumination of small areas of the visual field were recorded within the superficial laminae of the reinnervated SC 23 to 60 weeks after grafting. Each element of a typical bursting response to light consisted of a terminal potential (TP) (half width 164 +/- 25 microseconds, amplitude up to 171 microV) arising from a regenerated RGC axon terminal arborization, followed at a latency of 268 +/- 63 microseconds by a longer duration negative focal synaptic potential (FSP) (half width 938 +/- 396 msec, amplitude up to 188 microV) reflecting EPSPs in neurons within the terminal field of the regenerated RGC axon. The FSP but not the TP was attenuated in a dose-dependent manner by iontophoretic application of GABA. In some cases spikes arose from FSPs after the first two or three impulses of a train, presumably reflecting summation of EPSPs to threshold for excitation in SC neurons contacted by the regenerated RGC axon terminals. Up to one-third of the area of the SC can be infiltrated by arborizations of the regenerated RGC axons that enter the SC through a nerve graft inserted in the lateral aspect of the SC. These experiments indicate that terminal arborizations of individual regenerated RGC axons can synapse with multiple neurons in the SC and that convergence of inputs from regenerated RGC axons is not required for activation of SC neurons in response to light.
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Affiliation(s)
- Y Sauvé
- Centre for Research in Neuroscience, Montreal General Hospital, McGill University, Quebec, Canada
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23
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Affiliation(s)
- M Meyer
- Biomedical Imaging Center, University of Tennessee Medical Center, Knoxville 37920
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24
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Hartwich M, Kalsbeek A, Pévet P, Nürnberger F. Effects of illumination and enucleation on substance-P-immunoreactive structures in subcortical visual centers of golden hamster and Wistar rat. Cell Tissue Res 1994; 277:351-61. [PMID: 7521793 DOI: 10.1007/bf00327783] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The undecapeptide substance P is found in different entities of the visual system that control eye movement and synchronize endogenous rhythms with the light cycle (i.e., superior colliculus, suprachiasmatic nucleus, intergeniculate leaflet). Immunocytochemical methods were used to compare the reactivity to substance P in the brain of five groups of golden hamsters and two groups of Wistar rats: (1) untreated hamsters kept under 14L:10D and sacrificed at noon; (2) identically maintained animals sacrificed at midnight; (3) enucleated animals kept under control conditions; (4) hamsters kept under constant darkness; (5) hamsters kept under the same conditions as the controls, but intraventricularly injected with colchicine. The results obtained in golden hamsters of groups (1) and (3) were compared with findings in Wistar rats treated accordingly [groups (6) and (7)]. Substance P-immunoreactive perikarya were found in the suprachiasmatic nucleus and superior colliculus of hamsters and Wistar rats. Substance P-immunoreactive nerve fibers were abundant in the hypothalamic area ventral to the paraventricular nucleus, in the intergeniculate leaflet, in some thalamic nuclei, and in the superior colliculus. Immunoreactivity to substance P in the suprachiasmatic nucleus and intergeniculate leaflet did not vary among the experimental groups. However, a conspicuous decrease in reactivity to substance P was observed in the superficial layers of the superior colliculus of enucleated hamsters and rats, compared with all other groups. These results indicate that substance P immunoreactivity in the superior colliculus, but not that in the suprachiasmatic nucleus or intergeniculate leaflet, depends on the integrity of the retinal projection.
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Affiliation(s)
- M Hartwich
- Institut für Anatomie und Zytobiologie, Justus-Liebig-Universität, Giessen, Germany
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25
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Kobayashi S, Kishida R, Goris RC, Yoshimoto M, Ito H. Visual and infrared input to the same dendrite in the tectum opticum of the python, Python regius: electron-microscopic evidence. Brain Res 1992; 597:350-2. [PMID: 1473007 DOI: 10.1016/0006-8993(92)91494-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In snakes with infrared receptors, the optic tectum receives input from both the visual and the infrared senses. We investigated the infrared and optic fiber terminations in the tectum with a combination of horseradish peroxidase and degeneration labeling. In addition to synapses by visual and infrared fibers onto individual neurons, we were able to observe for the first time visual and infrared synapses on one and the same dendrite.
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Affiliation(s)
- S Kobayashi
- Department of Anatomy, School of Medicine, Yokohama City University, Japan
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Sasaki H, Fukuda Y, Hayashi Y. ON and OFF components of the receptive fields have different latencies to diffuse flashes of light in the superior colliculus of golden hamsters. Brain Res 1991; 540:345-8. [PMID: 2054629 DOI: 10.1016/0006-8993(91)90534-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Single unit activities were recorded from the superior colliculus in anesthetized hamsters. ON center and OFF center cells without surround showed short (within 150 ms) and long latency (longer than 150 ms) responses to diffuse flashes of light, respectively; ON and OFF center cells with an antagonistic surround and ON-OFF center cells showed both short and long latency responses. We suggest that the short latency discharges represent the activity of the ON component of the receptive field, while the long latency responses correspond to the OFF component. Thus, latencies of unit response to diffuse flashes of light may provide a useful indication of the existence of ON or OFF components in the receptive field.
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Affiliation(s)
- H Sasaki
- Department of Physiology, Hyogo College of Medicine, Japan
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27
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Olson MD, Meyer RL. The effect of TTX-activity blockade and total darkness on the formation of retinotopy in the goldfish retinotectal projection. J Comp Neurol 1991; 303:412-23. [PMID: 2007657 DOI: 10.1002/cne.903030307] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In the normal goldfish, neighboring retinal ganglion cells terminate in one small tectal locus to produce the precise retinotopy characteristic of this projection. This can be directly demonstrated by labeling neighboring ganglion cells with small "spot" injections of WGA-HRP, which yield a single small patch of product at the retinotopically appropriate part of the tectum. When the optic nerve is crushed, label from these spot injections was previously found to be widely dispersed during the early phase of regeneration. With time, label subsequently condensed, typically into several discrete patches reminiscent of ocular dominance columns. In this study, we tested whether the formation of these patches required impulse activity by injecting tetrodotoxin (TTX) into the eye during regeneration. We found that impulse blockade completely inhibited the formation of discrete patches while permitting considerable condensation of the label. This implies that these patches are generated by activity but that some map "refinement" utilized cellular processes that are activity independent. This activity-independent condensation progressed at a noticeably slower rate than the equivalent condensation seen with activity, thus suggesting that activity normally participates as a "helper factor," even though it is not strictly required. Since the formation of discrete patches during regeneration provides a sensitive measure of activity-dependent refinement, this was used to further address two controversial questions concerning the role of impulse activity. One is whether there is a chronologically defined critical period for activity-dependent refinement. This was tested by blocking impulse activity for 2 to 4 months, much longer than the activity-dependent refinement is thought to last, and then permitting activity to resume. We found that multiple patches were formed following this period of late activity, thus indicating that synaptic plasticity extends for several months beyond the supposed critical period. The other question was whether spontaneous retinal activity was sufficient for activity-dependent ordering. To test this, fish were kept in constant darkness during optic nerve crush and labelled with retinal spot injections at various times during regeneration. Condensation of label with the final formation of multiple patches formed at about the same time as fish with normal visual experience. This implies that the amount and extent of correlation of spontaneous activity in retina is adequate for driving activity-dependent refinement.
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Affiliation(s)
- M D Olson
- Department of Developmental and Cell Biology, University of California, Irvine 92717
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Brückner G, Mares V, Biesold D. Development of rat visual system after prenatal x-irradiation. Exp Pathol (Jena) 1980; 18:204-12. [PMID: 7398838 DOI: 10.1016/s0014-4908(80)80050-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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