A new view on post-receptoral signal processing in retino-geniculate pathways of humans.

• Applicant: Professor Dr. Jan Kremers
• Subject Area: Ophthalmology ; Cognitive, Systems and Behavioural Neurobiology
• Term: from 2013 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 239131698

• Final Report Year: 2017

Final Report Abstract

Spatial and temporal variabilities of L- and M-cone photoreceptor driven ERGs reflecting the activity of retinogeniculate (parvo- and magnocellular-based) and ON/OFF subpathways were established for the human retina using triple silent substitution stimuli. We found that L-cone driven responses were consistently larger than M-cone driven responses across the retina, with full-field L-cone stimulation producing the largest signals. Another key finding was that ERGs reflecting the activity of the two postreceptoral and ON/OFF mechanisms of the L- and M-cone pathways showed distinct spatial arrangements. M-cone driven responses to sawtooth stimuli had the opposite polarity compared to L-cone driven responses particularly for spatially restricted stimuli. The responses measured with sine-wave stimuli at high temporal frequencies, which reflect luminance sensitive magnocellular inputs, strongly depended upon spatial stimulus configuration. In contrast, those measured at low-to-intermediate temporal frequencies, which reflect cone-opponent parvocellular inputs, remained relatively more constant, with L- and M-cone driven responses being more similar in amplitude and approximately in counter-phase.

Publications

• Incremental and decremental L- and M-cone driven ERG responses: II. Sawtooth stimulation. J Opt Soc Am A (JOSA A) Opt Image Sci Vis 2014;31:A170-178
  Kremers J, Pangeni G, Tsaousis KT, McKeefry D, Murray IJ, Parry NR
  
• Incremental and decremental L- and M-cone-driven ERG responses: I. Square-wave pulse stimulation. JOSA A Opt Image Sci Vis 2014;31:A159-169
  McKeefry D, Kremers J, Kommanapalli D, et al.
  
• The spatial properties of L- and M-cone inputs to ERGs that reflect different types of post-receptoral processing. PloS one 2015;10:e0121218
  Jacob MM, Pangeni G, Gomes BD, Souza GS, da Silva Filho M, Silveira LC, Maguire J, Parry, NR, McKeefry DJ, Kremers J
  
• Spatial properties of L- and M-cone driven incremental (On-) and decremental (Off-) ERGs: evidence for the involvement of multiple post-receptoral mechanisms. JOSA A Opt Image Sci Vis 2016;33:A1-11
  Tsai TI, Jacob MM, McKeefry D, Murray IJ, Parry NR, Kremers J
  
• The influence of stimulus size on heterochromatic modulation ERGs. J Vis 2016;16:13
  Martins CM, Tsai T, Barboni MT, da Costa MF, Nagy B, Ventura DF, Kremers J
  
• Towards an ERG assay for studying colour vision in human observers. Doc Ophthalmol 2016;133:109-120
  Kremers J, Bhatt D.Kremers J, Bhatt D.