TY - JOUR AB - A new class of large-field tangential neurones (Figure Detection (FD-) cells) has been found and analysed in the lobula plate, the posterior part of the third visual ganglion, of the fly by combined extra-and intracellular recording as well as Lucifer Yellow injection. The FD-cells are likely to play a prominent role in figure-ground discrimination. Together with the Horizontal Cells, the output elements of the neuronal network underlying the optomotor course control reaction, they seem to be appropriate to account for the characteristic yaw torque response to relative motion. The FD-cells might thus compensate for the ldquodeficitsrdquo of the Horizontal Cells with respect to figureground discrimination (see Egelhaaf, 1985a). The FD-cells are directionally selective for either front-to-back (FD 1, FD 4) or back-to-front motion (FD 2, FD 3). Their excitatory receptive fields cover part of (FD 1, FD 2, FD 3) or the entire horizontal extent (FD 4) of the visual field of one eye. Their most important common property in the context of figureground discrimination is that they are more sensitive to relatively small objects than to spatially extended patterns. Their response to a small figure is much reduced by simultaneous large-field motion in front of the ipsi-as well as the contralateral eye. This large-field inhibition is either directionally selective or bidirectional, depending on the FD-cell under consideration. The main dendritic arborization of all FD-cells resides in the lobula plate. Their axonal projections lie in either the ipsi-or contralateral posterior optic foci and, thus, in the same area as the terminals of the Horizontal Cells. The FD-cells are, therefore, appropriate candidates for output elements of the optic lobes involved in figure-ground discrimination. DA - 1985 DO - 10.1007/BF00339948 KW - Cell biology KW - Physiology KW - Sensory reception KW - Neural coordination KW - Morphology LA - eng IS - 3 M2 - 195 PY - 1985 SN - 0 SP - 195-209 T2 - Biological Cybernetics TI - On the neuronal basis of figure-ground discrimination by relative motion in the visual system of the fly. 2: Figure-dectection cells, a new class of visual interneurones UR - https://nbn-resolving.org/urn:nbn:de:0070-pub-17740828 Y2 - 2024-11-22T09:29:52 ER -