Figure 6.

Conditionally polarization-sensitive CPU4 neurons. A, Reconstruction of a CPU4c neuron viewed from posterior. Smooth arborizations are present in the PB, whereas endings in the CBU (layer III) and in layer III of the upper unit of the contralateral nodulus (NoU) are varicose. B, Mean response of the polarization-sensitive neuron in A during four rotations of the polarizer (bin size 10°; error bars, SD; p = 4.2 × 10⁻¹⁰). imp., Impulses. C, Mean spiking activity (two rotations of the polarizer) of a polarization-blind CPU4b neuron (bin size 10°; error bars, SD; p = 0.99). D, Spiking activity and mean frequency of the CPU4c neuron shown in A during clockwise rotation of the polarizer. E, Activity of the CPU4b neuron (same as in C) during stimulation with a rotating polarizer (spike train and mean frequency). NoL, Lower unit of the nodulus. Scale bar, 50 μm.