title: Cockroach optomotor responses below single photon level.
abstract: Reliable vision in dim light depends on the efficient capture of photons. Moreover, visually guided behaviour requires reliable signals from the photoreceptors to generate appropriate motor reactions. Here, we show that at behavioural low-light threshold, cockroach photoreceptors respond to moving gratings with single-photon absorption events known as 'quantum bumps' at or below the rate of 0.1 s(-1). By performing behavioural experiments and intracellular recordings from photoreceptors under identical stimulus conditions, we demonstrate that continuous modulation of the photoreceptor membrane potential is not necessary to elicit visually guided behaviour. The results indicate that in cockroach motion detection, massive temporal and spatial pooling takes place throughout the eye under dim conditions, involving currently unknown neural processing algorithms. The extremely high night-vision capability of the cockroach visual system provides a roadmap for bio-mimetic imaging design.
authors.affiliation: Department of Physics, University of Oulu, Oulu, FI-90014, Finland Biocenter Oulu, University of Oulu, Oulu, FI-90014, Finland.
authors.forename: Anna
authors.initials: A
authors.lastname: Honkanen
authors.affiliation: Department of Physics, University of Oulu, Oulu, FI-90014, Finland.
authors.forename: Jouni
authors.initials: J
authors.lastname: Takalo
authors.affiliation: Department of Physics, University of Oulu, Oulu, FI-90014, Finland.
authors.forename: Kyösti
authors.initials: K
authors.lastname: Heimonen
authors.affiliation: Department of Physics, University of Oulu, Oulu, FI-90014, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Vähäsöyrinki
authors.affiliation: Department of Physics, University of Oulu, Oulu, FI-90014, Finland matti.weckstrom@oulu.fi.
authors.forename: Matti
authors.initials: M
authors.lastname: Weckström
mesh_terms: D000818:Animals; D003058:Cockroaches / Q000502:physiology*; D003623:Dark Adaptation / Q000502:physiology; D008027:Light; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D009043:Motor Activity / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D017785:Photons; D017956:Photoreceptor Cells, Invertebrate / Q000502:physiology*; D012684:Sensory Thresholds
keywords: Behaviour; Intracellular; Optomotor; Photoreceptor