Signaling – transcription interactions in mouse retinal ganglion cells early axon pathfinding –a literature review
Sending an axon out of the eye and into the target brain nuclei is the defining feature of retinal ganglion cells (RGCs). The literature on RGC axon pathfinding is vast, but it focuses mostly on decision making events such as midline crossing at the optic chiasm or retinotopic mapping at the target...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-05-01
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| Series: | Frontiers in Ophthalmology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fopht.2023.1180142/full |
| _version_ | 1797825492668121088 |
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| author | Raluca Paşcalău Raluca Paşcalău Tudor Constantin Badea Tudor Constantin Badea |
| author_facet | Raluca Paşcalău Raluca Paşcalău Tudor Constantin Badea Tudor Constantin Badea |
| author_sort | Raluca Paşcalău |
| collection | DOAJ |
| description | Sending an axon out of the eye and into the target brain nuclei is the defining feature of retinal ganglion cells (RGCs). The literature on RGC axon pathfinding is vast, but it focuses mostly on decision making events such as midline crossing at the optic chiasm or retinotopic mapping at the target nuclei. In comparison, the exit of RGC axons out of the eye is much less explored. The first checkpoint on the RGC axons’ path is the optic cup - optic stalk junction (OC-OS). OC-OS development and the exit of the RGC pioneer axons out of the eye are coordinated spatially and temporally. By the time the optic nerve head domain is specified, the optic fissure margins are in contact and the fusion process is ongoing, the first RGCs are born in its proximity and send pioneer axons in the optic stalk. RGC differentiation continues in centrifugal waves. Later born RGC axons fasciculate with the more mature axons. Growth cones at the end of the axons respond to guidance cues to adopt a centripetal direction, maintain nerve fiber layer restriction and to leave the optic cup. Although there is extensive information on OC-OS development, we still have important unanswered questions regarding its contribution to the exit of the RGC axons out of the eye. We are still to distinguish the morphogens of the OC-OS from the axon guidance molecules which are expressed in the same place at the same time. The early RGC transcription programs responsible for axon emergence and pathfinding are also unknown. This review summarizes the molecular mechanisms for early RGC axon guidance by contextualizing mouse knock-out studies on OC-OS development with the recent transcriptomic studies on developing RGCs in an attempt to contribute to the understanding of human optic nerve developmental anomalies. The published data summarized here suggests that the developing optic nerve head provides a physical channel (the closing optic fissure) as well as molecular guidance cues for the pioneer RGC axons to exit the eye. |
| first_indexed | 2024-03-13T10:54:44Z |
| format | Article |
| id | doaj.art-d52b121ec34f477c94f191a516959dc4 |
| institution | Directory Open Access Journal |
| issn | 2674-0826 |
| language | English |
| last_indexed | 2024-03-13T10:54:44Z |
| publishDate | 2023-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Ophthalmology |
| spelling | doaj.art-d52b121ec34f477c94f191a516959dc42023-05-17T05:40:52ZengFrontiers Media S.A.Frontiers in Ophthalmology2674-08262023-05-01310.3389/fopht.2023.11801421180142Signaling – transcription interactions in mouse retinal ganglion cells early axon pathfinding –a literature reviewRaluca Paşcalău0Raluca Paşcalău1Tudor Constantin Badea2Tudor Constantin Badea3Research and Development Institute, Transilvania University of Braşov, Braşov, RomaniaOphthalmology Clinic, Cluj County Emergency Hospital, Cluj-Napoca, RomaniaResearch and Development Institute, Transilvania University of Braşov, Braşov, RomaniaNational Center for Brain Research, Institutul de Cercetări pentru Inteligență Artificială, Romanian Academy, Bucharest, RomaniaSending an axon out of the eye and into the target brain nuclei is the defining feature of retinal ganglion cells (RGCs). The literature on RGC axon pathfinding is vast, but it focuses mostly on decision making events such as midline crossing at the optic chiasm or retinotopic mapping at the target nuclei. In comparison, the exit of RGC axons out of the eye is much less explored. The first checkpoint on the RGC axons’ path is the optic cup - optic stalk junction (OC-OS). OC-OS development and the exit of the RGC pioneer axons out of the eye are coordinated spatially and temporally. By the time the optic nerve head domain is specified, the optic fissure margins are in contact and the fusion process is ongoing, the first RGCs are born in its proximity and send pioneer axons in the optic stalk. RGC differentiation continues in centrifugal waves. Later born RGC axons fasciculate with the more mature axons. Growth cones at the end of the axons respond to guidance cues to adopt a centripetal direction, maintain nerve fiber layer restriction and to leave the optic cup. Although there is extensive information on OC-OS development, we still have important unanswered questions regarding its contribution to the exit of the RGC axons out of the eye. We are still to distinguish the morphogens of the OC-OS from the axon guidance molecules which are expressed in the same place at the same time. The early RGC transcription programs responsible for axon emergence and pathfinding are also unknown. This review summarizes the molecular mechanisms for early RGC axon guidance by contextualizing mouse knock-out studies on OC-OS development with the recent transcriptomic studies on developing RGCs in an attempt to contribute to the understanding of human optic nerve developmental anomalies. The published data summarized here suggests that the developing optic nerve head provides a physical channel (the closing optic fissure) as well as molecular guidance cues for the pioneer RGC axons to exit the eye.https://www.frontiersin.org/articles/10.3389/fopht.2023.1180142/fulloptic nerveretinal ganglion cellstranscriptiondevelopmentoptic stalk |
| spellingShingle | Raluca Paşcalău Raluca Paşcalău Tudor Constantin Badea Tudor Constantin Badea Signaling – transcription interactions in mouse retinal ganglion cells early axon pathfinding –a literature review Frontiers in Ophthalmology optic nerve retinal ganglion cells transcription development optic stalk |
| title | Signaling – transcription interactions in mouse retinal ganglion cells early axon pathfinding –a literature review |
| title_full | Signaling – transcription interactions in mouse retinal ganglion cells early axon pathfinding –a literature review |
| title_fullStr | Signaling – transcription interactions in mouse retinal ganglion cells early axon pathfinding –a literature review |
| title_full_unstemmed | Signaling – transcription interactions in mouse retinal ganglion cells early axon pathfinding –a literature review |
| title_short | Signaling – transcription interactions in mouse retinal ganglion cells early axon pathfinding –a literature review |
| title_sort | signaling transcription interactions in mouse retinal ganglion cells early axon pathfinding a literature review |
| topic | optic nerve retinal ganglion cells transcription development optic stalk |
| url | https://www.frontiersin.org/articles/10.3389/fopht.2023.1180142/full |
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