Fig. 2. Responses of LoTu1 to dorsally presented polarized light (Dors pol-light). (A) Intracellular recording traces during stimulation with three polarized monochromatic light stimuli at 9.0x10⁹ photons cm^–2 s^–1. Bars below the recording traces indicate the duration of the stimuli and the direction of rotation. (B) Relative spiking activities at _max (open bars) and response strength R (solid black bars; for definition, see Materials and methods) in response to three polarized monochromatic lights (means ± s.e.m.). Relative spiking activity at _max and R are significantly larger in response to polarized blue light than to UV and green light, *P<0.05; **P<0.01 (t-test). (C,D) Intensity/response curves of neural activity at _max (C) and R (D) in response to polarized blue (450 nm) light (means ± s.e.m.). Maximum light intensity (logI=0) is 10.6x10¹² photons cm^–2 s^–1. Solid lines show fits of Naka–Rushton functions with the fitting parameters rA_max=0.98, K=–3.33 log units, n=0.83 (C) and rR_max=0.99, K=–3.28 log units, n=0.4 (D). Broken lines indicate background activity (C) and no-stimulus R value (D).