title: The spatial properties of L- and M-cone inputs to electroretinograms that reflect different types of post-receptoral processing.
abstract: We studied the spatial arrangement of L- and M-cone driven electroretinograms (ERGs) reflecting the activity of magno- and parvocellular pathways. L- and M-cone isolating sine wave stimuli were created with a four primary LED stimulator using triple silent substitution paradigms. Temporal frequencies were 8 and 12 Hz, to reflect cone opponent activity, and 30, 36 and 48 Hz to reflect luminance activity. The responses were measured for full-field stimuli and for different circular and annular stimuli. The ERG data confirm the presence of two different mechanisms at intermediate and high temporal frequencies. The responses measured at high temporal frequencies strongly depended upon spatial stimulus configuration. In the full-field conditions, the L-cone driven responses were substantially larger than the full-field M-cone driven responses and also than the L-cone driven responses with smaller stimuli. The M-cone driven responses at full-field and with 70° diameter stimuli displayed similar amplitudes. The L- and M-cone driven responses measured at 8 and 12 Hz were of similar amplitude and approximately in counter-phase. The amplitudes were constant for most stimulus configurations. The results indicate that, when the ERG reflects luminance activity, it is positively correlated with stimulus size. Beyond 35° retinal eccentricity, the retina mainly contains L-cones. Small stimuli are sufficient to obtain maximal ERGs at low temporal frequencies where the ERGs are also sensitive to cone-opponent processing.
authors.affiliation: Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany; Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil.
authors.forename: Mellina M
authors.initials: MM
authors.lastname: Jacob
authors.affiliation: Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Gobinda
authors.initials: G
authors.lastname: Pangeni
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil.
authors.forename: Bruno D
authors.initials: BD
authors.lastname: Gomes
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brazil.
authors.forename: Givago S
authors.initials: GS
authors.lastname: Souza
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil.
authors.forename: Manoel
authors.initials: M
authors.lastname: da Silva Filho
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brazil.
authors.forename: Luiz Carlos L
authors.initials: LC
authors.lastname: Silveira
authors.affiliation: Vision Science Centre, Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom; School of Optometry and Vision Science, University of Bradford, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Maguire
authors.affiliation: Centre for Hearing and Vision Research, Institute of Human Development, University of Manchester, United Kingdom; Vision Science Centre, Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom; School of Optometry and Vision Science, University of Bradford, United Kingdom.
authors.forename: Neil R A
authors.initials: NR
authors.lastname: Parry
authors.affiliation: School of Optometry and Vision Science, University of Bradford, United Kingdom.
authors.forename: Declan J
authors.initials: DJ
authors.lastname: McKeefry
authors.affiliation: Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany; School of Optometry and Vision Science, University of Bradford, United Kingdom.
authors.forename: Jan
authors.initials: J
authors.lastname: Kremers
mesh_terms: D000328:Adult; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology / Q000502:physiology*; D062206:Spatial Analysis