Temporal analysis of electroretinographic responses in fishes with rod-dominated and mixed rod-cone retina.
Gen Physiol Biophys
; 28(3): 276-82, 2009 Sep.
Article
em En
| MEDLINE
| ID: mdl-20037193
Photoreceptor content of fish retinas could be accessed by comparative electroretinographic (ERG) studies using flickering light stimuli that could separate rod-mediated vision where critical flicker frequency (CFF, frequency when the eye loses its ability to resolve individual light pulses) is usually less than 15 Hz from cone-mediated vision. Four fish species inhabiting different photic environments (small-spotted dogfish shark--Scyliorhinus canicula, eel--Anguilla anguilla, painted comber--Serranus scriba, Prussian carp--Carassius gibelio) were investigated. Dogfish shark b-wave amplitudes significantly decreased at low frequency of stimulation and CFF was reached at 3.2 Hz. A similar effect on the b-wave amplitude was observed in the eel, but CFF occurred at around 20 Hz. Conversely, b-waves of painted comber and Prussian carp remained unaltered under intermittent low-frequency stimulation, and CFFs were around 25 and 30 Hz, respectively. Additional support in accessing the receptor content of fish retinas was given by the characterization of the OFF-response (d-wave) after light adaptation. Monotonous time course of the b-wave dark adaptation indicated a rod dominated retina of the dogfish shark. Observed results indicate that the dogfish shark possesses preponderantly rod retina, that of the eel is rod-dominated, while Prussian carp and painted comber have cone-rich retinae.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Retina
/
Células Fotorreceptoras Retinianas Bastonetes
/
Células Fotorreceptoras Retinianas Cones
/
Peixes
Limite:
Animals
Idioma:
En
Revista:
Gen Physiol Biophys
Ano de publicação:
2009
Tipo de documento:
Article