ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2016-04-07
    Description: In bright light, cone-photoreceptors are active and colour vision derives from a comparison of signals in cones with different visual pigments. This comparison begins in the retina, where certain retinal ganglion cells have 'colour-opponent' visual responses-excited by light of one colour and suppressed by another colour. In dim light, rod-photoreceptors are active, but colour vision is impossible because they all use the same visual pigment. Instead, the rod signals are thought to splice into retinal circuits at various points, in synergy with the cone signals. Here we report a new circuit for colour vision that challenges these expectations. A genetically identified type of mouse retinal ganglion cell called JAMB (J-RGC), was found to have colour-opponent responses, OFF to ultraviolet (UV) light and ON to green light. Although the mouse retina contains a green-sensitive cone, the ON response instead originates in rods. Rods and cones both contribute to the response over several decades of light intensity. Remarkably, the rod signal in this circuit is antagonistic to that from cones. For rodents, this UV-green channel may play a role in social communication, as suggested by spectral measurements from the environment. In the human retina, all of the components for this circuit exist as well, and its function can explain certain experiences of colour in dim lights, such as a 'blue shift' in twilight. The discovery of this genetically defined pathway will enable new targeted studies of colour processing in the brain.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Joesch, Maximilian -- Meister, Markus -- England -- Nature. 2016 Apr 14;532(7598):236-9. doi: 10.1038/nature17158. Epub 2016 Apr 6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Harvard University, 52 Oxford Street, Cambridge, Massachusetts 02138, USA. ; Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/27049951" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Color ; Color Perception/*physiology/radiation effects ; Color Vision/*physiology/radiation effects ; Darkness ; Female ; Humans ; Male ; Mice ; Models, Neurological ; Neural Pathways/*physiology/radiation effects ; Retinal Cone Photoreceptor Cells/*metabolism/radiation effects ; Retinal Ganglion Cells/metabolism/radiation effects ; Retinal Rod Photoreceptor Cells/*metabolism/radiation effects ; Synapses/metabolism/radiation effects ; Territoriality ; Ultraviolet Rays
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2010-11-12
    Description: Motion vision is a major function of all visual systems, yet the underlying neural mechanisms and circuits are still elusive. In the lamina, the first optic neuropile of Drosophila melanogaster, photoreceptor signals split into five parallel pathways, L1-L5. Here we examine how these pathways contribute to visual motion detection by combining genetic block and reconstitution of neural activity in different lamina cell types with whole-cell recordings from downstream motion-sensitive neurons. We find reduced responses to moving gratings if L1 or L2 is blocked; however, reconstitution of photoreceptor input to only L1 or L2 results in wild-type responses. Thus, the first experiment indicates the necessity of both pathways, whereas the second indicates sufficiency of each single pathway. This contradiction can be explained by electrical coupling between L1 and L2, allowing for activation of both pathways even when only one of them receives photoreceptor input. A fundamental difference between the L1 pathway and the L2 pathway is uncovered when blocking L1 or L2 output while presenting moving edges of positive (ON) or negative (OFF) contrast polarity: blocking L1 eliminates the response to moving ON edges, whereas blocking L2 eliminates the response to moving OFF edges. Thus, similar to the segregation of photoreceptor signals in ON and OFF bipolar cell pathways in the vertebrate retina, photoreceptor signals segregate into ON-L1 and OFF-L2 channels in the lamina of Drosophila.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Joesch, Maximilian -- Schnell, Bettina -- Raghu, Shamprasad Varija -- Reiff, Dierk F -- Borst, Alexander -- England -- Nature. 2010 Nov 11;468(7321):300-4. doi: 10.1038/nature09545.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉MPI for Neurobiology, Department of Systems and Computational Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21068841" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Calcium Signaling/radiation effects ; Drosophila melanogaster/cytology/metabolism/*physiology/radiation effects ; Female ; Gap Junctions/metabolism/radiation effects ; Light ; Models, Neurological ; *Motion ; Motion Perception/*physiology/radiation effects ; Optic Lobe, Nonmammalian/cytology/physiology/radiation effects ; Photoreceptor Cells, Invertebrate/metabolism/radiation effects ; Vision, Ocular/*physiology/radiation effects ; Visual Pathways/cytology/*physiology/radiation effects
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...