scholarly journals Nell2 regulates the contralateral-versus-ipsilateral visual projection as a layer-specific positional cue

2018 ◽  
Author(s):  
Chizu Nakamoto ◽  
Elaine Durward ◽  
Masato Horie ◽  
Masaru Nakamoto
Keyword(s):  
Axon Guidance ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Retinal Ganglion ◽  
Guidance Cue ◽  
Retinal Axons ◽  
Visual Projection ◽  
Summary Statement ◽  
Retinogeniculate Projection ◽  
Dorsal Lateral Geniculate

SUMMARY STATEMENTNell2 is an ipsilateral layer-specific axon guidance cue in the visual thalamus and contributes to establishment of the eye-specific retinogeniculate projection by specifically inhibiting contralateral retinal axons.ABSTRACTIn mammals with binocular vision, retinal ganglion cell (RGC) axons from each eye project to eye-specific layers in the contralateral and ipsilateral dorsal lateral geniculate nucleus (dLGN). Although layer-specific axon guidance cues that discriminate contralateral and ipsilateral RGC axons have long been postulated as a key mechanism for development of the eye-specificretinogeniculate projection, the molecular nature of such cues has remained elusive. Here we show that the extracellular glycoprotein Nell2 (also known as Nel) is expressed in the dorsomedial region of the dLGN, which corresponds to the layer receiving ipsilateral RGC axons. In Nell2 mutant mice, contralateral RGC axons invaded the ipsilateral layer 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 layer-specific positional label in the dLGN that discriminates contralateral and ipsilateral RGC axons, and that it plays essential roles in establishment of the eye-specific projection patterns in the retinogeniculate system.

scholarly journals Phr1 is required for proper retinocollicular targeting of nasal–dorsal retinal ganglion cells

2011 ◽  
Vol 28 (2) ◽  
pp. 175-181 ◽  
Author(s):  
BRADLY Q. VO ◽  
A. JOSEPH BLOOM ◽  
SUSAN M. CULICAN
Keyword(s):  
Normal Development ◽  
Ganglion Cells ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Retinal Ganglion ◽  
Topographic Map ◽  
Local Refinement ◽  
Retinal Axons ◽  
Retinogeniculate Projection ◽  
Dorsal Lateral Geniculate ◽  
Retinocollicular Projection

AbstractPrecise targeting of retinal projections is required for the normal development of topographic maps in the mammalian primary visual system. During development, retinal axons project to and occupy topographically appropriate positions in the dorsal lateral geniculate nucleus (dLGN) and superior colliculus (SC). Phr1 retinal mutant mice, which display mislocalization of the ipsilateral retinogeniculate projection independent of activity and ephrin-A signaling, were found to have a more global disruption of topographic specificity of retinofugal inputs. The retinocollicular projection lacks local refinement of terminal zones and multiple ectopic termination zones originate from the dorsal–nasal (DN) retinal quadrant. Similarly, in the dLGN, the inputs originating from the contralateral DN retina are poorly refined in the Phr1 mutant. These results show that Phr1 is an essential regulator of retinal ganglion cell projection during both dLGN and SC topographic map development.

scholarly journals Loss of Binocular Responses and Reduced Retinal Convergence During the Period of Retinogeniculate Axon Segregation

2006 ◽  
Vol 96 (5) ◽  
pp. 2775-2784 ◽  
Author(s):  
Jokūbas Z̆iburkus ◽  
William Guido
Keyword(s):  
Optic Nerve ◽  
Ganglion Cells ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Retinal Ganglion ◽  
Retinal Projections ◽  
Axon Terminals ◽  
Age Related ◽  
Dorsal Lateral Geniculate ◽  
Anterograde Labeling

In the developing mammalian visual system, axon terminals from the two eyes overlap in the dorsal lateral geniculate nucleus (LGN) but then undergo a period of refinement and segregate to form distinct eye-specific domains. We report on the changes in synaptic transmission that occur in rodent LGN during the period of retinogeniculate axon segregation by using anterograde labeling techniques in conjunction with an in vitro preparation where large segments of each optic nerve are preserved. Anterograde labeling of retinal projections in early postnatal day (P) rats with cholera toxin β subunit indicated an age-related recession in uncrossed retinal projections. Between P2 and P5 uncrossed projections occupied as much as 50% of the LGN and overlapped substantially with crossed projections. Between the first and second postnatal week uncrossed projections receded, so by P14 they assumed an adultlike profile occupying 15–20% of LGN and showed little or no overlap with crossed projections. The postsynaptic responses of LGN cells evoked by the separate stimulation of each optic nerve indicated that before P14, many relay cells were binocularly innervated and received at least four to six inputs from each eye. However, these features of retinogeniculate connectivity were transient and their attrition occurred in concert with a retraction of retinal arbors into nonoverlapping, eye-specific regions. By P18 cells were monocularly innervated and received input from one to three retinal ganglion cells. These results provide a better understanding of the underlying changes in synaptic circuitry that occur during the anatomical segregation of retinal inputs into eye-specific territories.

scholarly journals CRMP2 and CRMP4 Are Differentially Required for Axon Guidance and Growth in Zebrafish Retinal Neurons

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Zhi-Zhi Liu ◽  
Jian Zhu ◽  
Chang-Ling Wang ◽  
Xin Wang ◽  
Ying-Ying Han ◽  
...  
Keyword(s):  
Axon Guidance ◽  
Retinal Ganglion ◽  
Guidance Cues ◽  
Retinal Axons ◽  
Neuropilin 1 ◽  
Axon Development ◽  
Intracellular Proteins ◽  
Retinal Axon

Axons are directed to their correct targets by guidance cues during neurodevelopment. Many axon guidance cues have been discovered; however, much less known is about how the growth cones transduce the extracellular guidance cues to intracellular responses. Collapsin response mediator proteins (CRMPs) are a family of intracellular proteins that have been found to mediate growth cone behavior in vitro; however, their roles in vivo in axon development are much less explored. In zebrafish embryos, we find that CRMP2 and CRMP4 are expressed in the retinal ganglion cell layer when retinal axons are crossing the midline. Knocking down CRMP2 causes reduced elongation and premature termination of the retinal axons, while knocking down CRMP4 results in ipsilateral misprojections of retinal axons that would normally project to the contralateral brain. Furthermore, CRMP4 synchronizes with neuropilin 1 in retinal axon guidance, suggesting that CRMP4 might mediate the semaphorin/neuropilin signaling pathway. These results demonstrate that CRMP2 and CRMP4 function differentially in axon development in vivo.

Unitary EPSCs of Corticogeniculate Fibers in the Rat Dorsal Lateral Geniculate Nucleus In Vitro

2003 ◽  
Vol 89 (6) ◽  
pp. 2952-2960 ◽  
Author(s):  
Björn Granseth ◽  
Sivert Lindström
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Feedback System ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Size Distributions ◽  
Principal Cells ◽  
Quantal Size ◽  
Lateral Geniculate ◽  
Whole Cell Patch Clamp ◽  
Dorsal Lateral Geniculate

To investigate unitary corticogeniculate excitatory postsynaptic currents (EPSCs), whole cell patch-clamp recordings were obtained from 20 principal cells in slices of the dorsal lateral geniculate nucleus (dLGN) of DA-HAN rats. EPSCs, evoked by electrical stimulation of corticogeniculate axons, had size distributions with one or more quantal peaks. Gaussian curves fitted to such distributions gave a mean quantal size ( q) of -5.0 ± 0.7 (SD) pA for the EPSCs. Paired-pulse ratio (EPSC2/EPSC1) was 3.3 ± 0.9 for stimuli separated by 40 ms. The mean quantal size was similar for facilitated EPSCs (-5.2 ± 0.8 pA), implying an increase in mean quantal content ( m). Most corticogeniculate axons were capable of releasing only one or two quanta onto individual principal cells. Mean resting release probability ( p) was low, 0.09 ± 0.04. Binomial models, with the same n but increased p, could account for both the basal and facilitated EPSC size distributions in 6/8 cells. It is suggested that the low resting efficacy of corticogeniculate synapses serves to stabilize this excitatory feedback system. The pronounced facilitation in conjunction with large convergence from many corticogeniculate cells would provide a transient, potent excitation of dLGN cells, compliant with the idea of a visually driven neuronal amplifier.

Mathematical models for the spatial receptive-field organization of nonlagged X-cells in dorsal lateral geniculate nucleus of cat

2000 ◽  
Vol 17 (6) ◽  
pp. 871-885 ◽  
Author(s):  
G.T. EINEVOLL ◽  
P. HEGGELUND
Keyword(s):  
Receptive Field ◽  
Ganglion Cell ◽  
Lateral Geniculate Nucleus ◽  
Discrete Model ◽  
Receptive Fields ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Retinal Ganglion ◽  
Lateral Geniculate ◽  
X Cells ◽  
Dorsal Lateral Geniculate

Spatial receptive fields of relay cells in dorsal lateral geniculate nucleus (dLGN) have commonly been modeled as a difference of two Gaussian functions. We present alternative models for dLGN cells which take known physiological couplings between retina and dLGN and within dLGN into account. The models include excitatory input from a single retinal ganglion cell and feedforward inhibition via intrageniculate interneurons. Mathematical formulas describing the receptive field and response to circular spot stimuli are found both for models with a finite and an infinite number of ganglion-cell inputs to dLGN neurons. The advantage of these models compared to the common difference-of-Gaussians model is that they, in addition to providing mathematical descriptions of the receptive fields of dLGN neurons, also make explicit contributions from the geniculate circuit. Moreover, the model parameters have direct physiological relevance and can be manipulated and measured experimentally. The discrete model is applied to recently published data (Ruksenas et al., 2000) on response versus spot-diameter curves for dLGN cells and for the retinal input to the cell (S-potentials). The models are found to account well for the results for the X-cells in these experiments. Moreover, predictions from the discrete model regarding receptive-field sizes of interneurons, the amount of center-surround antagonism for interneurons compared to relay cells, and distance between neighboring retinal ganglion cells providing input to interneurons, are all compatible with data available in the literature.

An In Vitro Model of the Kitten Retinogeniculate Pathway

1997 ◽  
Vol 77 (1) ◽  
pp. 511-516 ◽  
Author(s):  
William Guido ◽  
Fu-Sun Lo ◽  
Reha S. Erzurumlu
Keyword(s):  
In Vitro Model ◽  
Ganglion Cells ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Glutamate Antagonists ◽  
Electrophysiological Properties ◽  
Functional Connections ◽  
Retinal Axons ◽  
Retinal Explants ◽  
Vitro Model

Guido, William, Fu-Sun Lo, and Reha S. Erzurumlu. An in vitro model of the kitten retinogeniculate pathway. J. Neurophysiol. 77: 511–516, 1997. An organotypic explant coculture method is described for the developing retinogeniculate pathway of the cat. Retinal explants and thalamic slices containing the dorsal lateral geniculate nucleus (LGN), derived from early postnatal kittens, can be grown in serum-free culture medium for several days. In such cultures, retinal ganglion cells (RGCs) and LGN neurons retained their age-specific morphological features and developed functional connections. Labeling of RGCs and their processes with DiI showed that all three major classes of RGCs (α/Y, β/X, γ/W) were present in cocultured retinal explants. Retinal axons readily regenerated into thalamic slices and, over time, developed arbors within the LGN. Retrograde labeling from the LGN traced the origin of these axons almost exclusively to α-cells in the retina. In vitro intracellular recordings indicated that LGN cells maintained their basic electrophysiological properties in coculture. Current injection generated action potentials, and, at hyperpolarized levels, it led to low-threshold Ca2+ spiking. Regenerated retinal axons also formed functional connections with LGN neurons. Electrical stimulation of the retinal explant elicited excitatory postsynaptic responses (EPSPs) in LGN cells. Drop application of specific glutamate antagonists indicated that EPSPs had both N-methyl-d-aspartate (NMDA) and non-NMDA receptor components. The morphology of the LGN neurons was examined after intracellular injections of biocytin during recording. Labeled cells were very similar to those of early postnatal kittens. Although, in general, they had relatively small soma and simple dendritic branching patterns, a few could be recognized as X- or Y-cells. Thus the coculture model can be used to assay the regenerative propensity of different types of RGCs during development.

scholarly journals The ventral and dorsal lateral geniculate nucleus of the rat: intracellular recordings in vitro.

1987 ◽  
Vol 384 (1) ◽  
pp. 587-601 ◽  
Author(s):  
V Crunelli ◽  
J S Kelly ◽  
N Leresche ◽  
M Pirchio
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Intracellular Recordings ◽  
Lateral Geniculate ◽  
Dorsal Lateral Geniculate

scholarly journals Development of the mammalian retinogeniculate pathway: target finding, transient synapses and binocular segregation

1990 ◽  
Vol 153 (1) ◽  
pp. 85-104 ◽  
Author(s):  
K. F. So ◽  
G. Campbell ◽  
A. R. Lieberman
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Mammalian Species ◽  
Postnatal Period ◽  
Good Evidence ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Retinal Ganglion ◽  
Ultrastructural Studies ◽  
Embryonic Life ◽  
Retinogeniculate Projection

This review is concerned with the development of the mammalian retinogeniculate projection from the perspective of our studies on the hamster and to a lesser extent on the cat. In these, and other mammalian species, axons from the two eyes initially spread throughout the dorsal lateral geniculate nucleus (dLGN) and thus completely overlap. Later they segregate, the axons from each eye coming to occupy discrete, non-overlapping territories within the dLGN. The process of segregation to establish the adult pattern coincides with the death of retinal ganglion cells projecting to inappropriate areas of the dLGN and with the loss, by degeneration or retraction, of the axons and/or axonal branches initially located within inappropriate territory of the dLGN. These events occur in the early postnatal period in hamsters, before the eyes have opened, and in cats and monkeys they occur entirely during embryonic life: thus, they do not depend on the onset of normal visual function. If one eye is removed before segregation has begun, the terminal fields of the crossed and uncrossed axons from the remaining eye do not segregate, suggesting that segregation in normal development may depend on some form of interaction between retinal ganglion cells from the two eyes. Attractive and/or repulsive influences exerted by the dLGN on retinogeniculate axons may also be involved in the formation of eye-specific territories. Experimental ultrastructural studies in hamster and cat show that the overlap phase is associated with the formation, by inappropriately located axons, of transient synapses similar to those made by retinogeniculate axons in appropriate parts of the dLGN. In the cat, the transient synapses are made by the axon trunk and by side branches of retinogeniculate axons with terminal arbors in appropriate parts of the nucleus; the transient synapses disappear as the side branches are shed or retracted during the segregation period. Because of good evidence that electrical activity of the retinogeniculate axons may be involved in binocular segregation of inputs, we suggest that the formation and elimination of transient synapses play a significant role in the development of the orderly retinogeniculate projections.

The directed growth of retinal axons towards surgically transposed tecta in Xenopus; an examination of homing behaviour by retinal ganglion cell axons

Development ◽  
1990 ◽  
Vol 108 (1) ◽  
pp. 147-158
Author(s):  
J.S. Taylor
Keyword(s):  
Ganglion Cell ◽  
Axon Guidance ◽  
Retinal Ganglion Cell ◽  
Optic Tract ◽  
Retinal Ganglion ◽  
Retinal Axons ◽  
Dorsal Neural Tube ◽  
Abnormal Structure ◽  
Optic Axons ◽  
The Brain

The growth of optic axons towards experimentally rotated tecta has been studied. In stage 24/25 embryos, a piece of the dorsal neural tube, containing the dorsal midbrain rudiment, was rotated through 180 degrees. At later stages of development, the pathways of growing optic axons were investigated by labelling with either horseradish peroxidase or fluorescent dye. It is shown that retinal ganglion cell axons followed well-defined pathways, in spite of the abnormal structure of the brain, and were able to locate displaced tecta. This directed outgrowth of retinal axons in the optic tracts appears to be related either to the tectum or to some other component included in the graft operations. In tadpoles in which the midbrain rudiment was removed, optic axons still followed the normal course of the optic tract. This observation argues against long-range target attraction as being essential in guiding growing retinal axons towards the tectum. An alternative axon guidance mechanism, selective fasciculation, is discussed as a possible alternative to explain the directed axon outgrowth which occurs in both the normal and in these experimentally manipulated tadpoles.

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