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Abstract

Integrating binocular motion information tunes wide-field direction-selective neurons in the fly optic lobe to respond preferentially to specific optic
flow fields. This is shown by measuring the local preferred directions
(LPDs) and local motion sensitivities (LMSs) at many positions within the receptive
fields of three types of anatomically identifiable lobula plate tangential neurons: the three horizontal system (HS) neurons, the two centrifugal horizontal (CH)
neurons, and three heterolateral connecting elements. The latter impart to two of the HS and to both CH neurons a sensitivity to motion from the contralateral
visual field. Thus in two HS neurons and both CH neurons, the response field comprises part of the ipsi- and contralateral visual
hemispheres. The
distributions of LPDs within the binocular response fields of each neuron show marked similarities to the optic flow fields created by particular types of
self-movements of the fly. Based on the characteristic distributions of local preferred directions and motion sensitivities within the response fields, the
functional role of the respective neurons in the context of behaviorally relevant processing of visual wide-field motion is discussed.