Outdoor performance of a motion-sensitive neuron in the blowfly.
We studied an identified motion-sensitive neuron of the blowfly under outdoor conditions. The neuron was stimulated by oscillating the fly in a rural environment. We analysed whether the motion-induced neuronal activity is affected by brightness changes ranging between bright sunlight and dusk. In addition, the relationship between spike rate and ambient temperature was determined. The main results are: (1) The mean spike rate elicited by visual motion is largely independent of brightness changes over several orders of magnitude as they occur as a consequence of positional changes of the sun. Even during dusk the neuron responds strongly and directionally selective to motion. (2) The neuronal spike rate is not significantly affected by short-term brightness changes caused by clouds temporarily occluding the sun. (3) In contrast, the neuronal activity is much affected by changes in ambient temperature.
Egelhaaf
M
M
Lehrstuhl für Neurobiologie, Fakultät für Biologie, Universität Bielefeld, Postfach 10 01 31, D-33501 Bielefeld, Germany. martin.egelhaaf@biologie.uni-bielefeld.de
Grewe
J
J
Kern
R
R
Warzecha
A K
AK
D000221:Adaptation, Ocular / Q000502:physiology*; D000818:Animals; D004175:Diptera / Q000502:physiology*; D005071:Evoked Potentials; D008029:Lighting; D009039:Motion Perception / Q000502:physiology*; D009475:Neurons, Afferent / Q000502:physiology*; D010775:Photic Stimulation; D013696:Temperature