[Comparative study of the rod and cone contributions to the generation of b-wave ERG and tectal evoked potential in the dark-adapted carp].
Amplitudes and peak latencies as functions of wave length and monochromatic light intensity were investigated for b-wave ERG and tectal evoked potentials (EP) in the dark-adapted carp (Cyprinus carpio L). It was found, that independently of light intensity b-wave action spectra had one maximum in the medium wave band, corresponding to rod sensitivity area. For tectal EP, similar action spectra with maximum in the middle-wave were seen at low light intensity only. The b-wave amplitude growth was significant for the whole band of light intensities, and these changes were accompanied with a slight decrease in peak latency (to 50-100 ms). Tectal EP amplitude increased when low-intensity light was changed for medium intensity light and did not considerably increase to brighter light stimuli. However, tectal EP time latency significantly decreased (to 100-200 ms) during light intensity increasing. This differences show that retinal rod system, which in responsible for ERG b-wave in darkness, is not a key factor in the generation of tectal EP.
Garina
N S
NS
Erchenkov
V G
VG
Vorontsov
D D
DD
Semina
T K
TK
D000818:Animals; D002347:Carps / Q000502:physiology; D003623:Dark Adaptation / Q000502:physiology*; D004596:Electroretinography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D008027:Light; D010775:Photic Stimulation; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D013477:Superior Colliculi / Q000502:physiology*