Table 1.
Sensitivity to looming stimuli and small moving objects in CC neurons
| Cell type | Ipsilateral first trial | Contralateral first trial | Ipsilateral mean | Contralateral mean | Looming sensitivity | Small object sensitivity |
|---|---|---|---|---|---|---|
| TUx,1 Fig. 2 | + | + | + (4) | + (3) | Yes | n.t. |
| TUy, Fig. 3 | + | + | + (3) | + (5) | Yes | n.t. |
| TUz, Fig. 4 | − | + | − (5) | + (4) | Yes | n.t. |
| TU2 | o | + | + (3) | + (3) | Yes | n.t. |
| GFS | o | o | − (8) | o (5) | Yes | n.t. |
| GFS | o | o | − (5) | + (4) | Yes | Yes |
| GFSL1 | o | + | + (5) | + (10) | Yes | n.t. |
| GFSL2 | + | + | + (3) | + (3) | Yes | n.t. |
| GFS/PoU1 | + | + | + (4) | + (2) | Yes | Yes |
| GFS/PoU2 | o | − | o (4) | − (3) | Yes | n.t. |
| PoU1, Fig. 5C–E | + | − | + (3) | − (3) | Yes | Yes |
| PoU1, Fig. 5A,B | + | o | + (18) | o (5) | Yes | No |
| CU4, Fig. 6A,B | − | + | − (4) | + (4) | Yes | n.t. |
| CU4,2 Figs. 6C,D, 9B | + | + | + (4) | + (1) | Yes | Yes |
| TL3 | o | − | o (4) | − (6) | Yes | n.t. |
| CL1 | + | o | + (7) | o (7) | Yes | n.t. |
| CL1 | + | n.t. | + (3) | n.t. | Yes | No |
| CL1 | + | + | o (8) | o (5) | Yes | Yes |
| CL1 | o | o | o (2) | o (3) | No | n.t. |
| CL1 | o | + | o (5) | + (2) | Yes | Yes |
| CL1 | + | + | o (3) | + (2) | Yes | No |
| CL1 | + | + | + (6) | + (7) | Yes | No |
| CL1 | o | + | + (3) | + (4) | Yes | n.t. |
| CL1 | + | + | + (6) | + (13) | Yes | No |
| CL1 | + | + | + (7) | + (6) | Yes | n.t. |
| CL1 | + | o | + (5) | o (3) | Yes | n.t. |
| CL13 | + | o | + (5) | o (4) | Yes | No |
| CL1 | o | o | − (3) | o (3) | Yes | Yes |
| CL1 | − | + | − (3) | o (2) | Yes | n.t. |
| CL1 | − | − | − (6) | − (5) | Yes | n.t. |
| TB2 | + | + | + (2) | + (2) | Yes | Yes |
| TB2 | + | o | + (3) | o (2) | Yes | Yes |
| TB1, Fig. 9A | + | + | + (8) | + (6) | Yes | Yes |
| CPU1 | o | − | o (3) | − (2) | Yes | n.t. |
| CPU1 | − | n.t. | − (4) | n.t. | Yes | n.t. |
| CPU1 | − | − | − (4) | − (4) | Yes | n.t. |
| CPU1, Fig. 7 | − | − | − (3) | − (3) | Yes | Yes |
| PoU1/CPU1 | n.t. | − | n.t. | − (3) | Yes | No |
Neurons were classified as looming sensitive if the peak (+) or nadir (−) of spiking activity occurred within a time window ranging from the start of the looming stimulus until 500 ms after the prospective object collision time, either in the first trial or in the mean response of all trials on either eye. Trial number is given in brackets. o, peak or nadir activity occurred outside the critical time window. Neurons were classified as sensitive to small translating objects if the peak or nadir spiking rate occurred in response to the first translation in a sequence of object translations and rests. n.t., not tested. Nomenclature of cell types from Homberg (1994), Müller et al. (1997), Homberg et al. (1999), and Heinze and Homberg (2009). In two cases it was unclear whether we recorded from a GFS or a colabeled intrinsic neuron of the CBU (PoU1 neuron, respectively, PoU2 neuron; Heinze and Homberg, 2008). In one case it was unclear whether we recorded from a CPU1 or a colabeled PoU1 neuron. The input ramifications of the CPU1 neuron were contralateral to the input of PoU1. We classified regarding to the CPU1 neuron.
1The soma got lost during tissue processing, classified regarding to location of input (smooth) ramifications.
2The CU4 neuron also shown in Fig. 6C (responses in Figs. 6D and 9B) is marked as sensitive to the small objects although it does not fulfill the criterion (see text).
3 Ipsilateral and contralateral could not be determined because several neurons of the same type were stained: arbitrary classification.