Summary
This study identifies Tbr2 as a transcription factor essential for the development of intrinsically photosensitive retinal ganglion cells (ipRGCs) and other non-image-forming RGC types in mice. Loss of Tbr2 results in reduced projections to non-image-forming brain nuclei and an attenuated pupillary light reflex, advancing understanding of the neural circuitry underlying subconscious light-driven behaviors relevant to circadian entrainment.
Key Findings
- Tbr2 mutant mice show reduced retinal projections to non-image-forming nuclei (e.g., suprachiasmatic nucleus, olivary pretectal nucleus) compared to wild-type controls.
- Tbr2 mutants exhibit an attenuated pupillary light reflex, indicating functional loss of non-image-forming light-response circuits.
- Tbr2 is required for the development of multiple molecularly distinct RGC types, including intrinsically photosensitive RGCs (ipRGCs).
- Results demonstrate Tbr2 acts in RGC type specification and/or survival specifically within the subset of RGCs mediating subconscious light-induced behaviors.
Categories
The Science of Light: Investigates the molecular mechanisms underlying non-image-forming light circuits, including ipRGCs and the pupillary light reflex, via transcription factor Tbr2.
Author(s)
NT Sweeney, H Tierney, DA Feldheim
Publication Year
2014
Number of Citations
63
Related Publications
The Science of Light
- Phototransduction by retinal ganglion cells that set the circadian clock
- Color appearance models
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Melanopsin is required for non-image-forming photic responses in blind mice