The optokinetic reaction in foveate and afoveate geckos.
To investigate determinants of symmetry of the monocular horizontal optokinetic reaction (hOKR) in vertebrates, we performed behavioural studies in diurnal foveate, as well as nocturnal afoveate geckos. During binocular viewing hOKR gain was equal for movement to the left or right, during monocular stimulation, all afoveate geckos (Lepidodactylus lugubris, Gekko gecko, Eublepharis macularius) and the foveate Lygodactylus spp. exclusively reacted to temporo-nasal stimulation with stabilising head movements whereas in Phelsuma madagascariensis a naso-temporal component of hOKR could be elicited albeit much weaker. Thus, neither the presence of a fovea nor lifestyle seems to be decisive for a symmetrical monocular hOKR.
Masseck
Olivia
O
International Graduate School of Neuroscience, Ruhr University Bochum, Germany.
Röll
Beate
B
Hoffmann
Klaus-Peter
KP
D000818:Animals; D005584:Fovea Centralis / Q000502:physiology; D008116:Lizards / Q000502:physiology*; D009039:Motion Perception / Q000502:physiology*; D017120:Nystagmus, Optokinetic / Q000502:physiology*; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology; D015348:Vision, Binocular / Q000502:physiology; D015349:Vision, Monocular / Q000502:physiology