title: Spectral Sensitivity Measured with Electroretinogram Using a Constant Response Method.
abstract: A new method is presented to determine the retinal spectral sensitivity function S(λ) using the electroretinogram (ERG). S(λ)s were assessed in three different species of myomorph rodents, Gerbils (Meriones unguiculatus), Wistar rats (Ratus norvegicus), and mice (Mus musculus). The method, called AC Constant Method, is based on a computerized automatic feedback system that adjusts light intensity to maintain a constant-response amplitude to a flickering stimulus throughout the spectrum, as it is scanned from 300 to 700 nm, and back. The results are presented as the reciprocal of the intensity at each wavelength required to maintain a constant peak to peak response amplitude. The resulting S(λ) had two peaks in all three rodent species, corresponding to ultraviolet and M cones, respectively: 359 nm and 511 nm for mice, 362 nm and 493 nm for gerbils, and 362 nm and 502 nm for rats. Results for mouse and gerbil were similar to literature reports of S(λ) functions obtained with other methods, confirming that the ERG associated to the AC Constant-Response Method was effective to obtain reliable S(λ) functions. In addition, due to its fast data collection time, the AC Constant Response Method has the advantage of keeping the eye in a constant light adapted state.
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil.
authors.forename: Fernando Allan de Farias
authors.initials: FA
authors.lastname: Rocha
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: Bruno Duarte
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.|Universidade Ceuma, São Luís, Maranhão, Brazil.
authors.forename: Luiz Carlos de Lima
authors.initials: LC
authors.lastname: Silveira
authors.affiliation: Instituto de Psicologia, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Sonia Limara
authors.initials: SL
authors.lastname: Martins
authors.affiliation: Instituto de Psicologia, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Renata Genaro
authors.initials: RG
authors.lastname: Aguiar
authors.affiliation: Instituto de Psicologia, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: John Manuel
authors.initials: JM
authors.lastname: de Souza
authors.affiliation: Instituto de Psicologia, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Dora Fix
authors.initials: DF
authors.lastname: Ventura
mesh_terms: D000818:Animals; D004596:Electroretinography / Q000379:methods*; D005849:Gerbillinae; D051379:Mice; D051381:Rats; D017208:Rats, Wistar; D012984:Software