Figure 1.

Lack of resolvable quantum bumps in ciliary cells. (A) Example of single-photon responses in a rhabdomeric photoreceptor voltage clamped at −50 mV. Light steps of the indicated relative intensities were presented for 10 s. (B) Smooth photocurrent evoked by threshold stimulation in a ciliary photoreceptor. Similar protocol as in A, except that the holding potential was −30 mV. Unattenuated light intensity: 3.8 × 10¹⁵ photons · cm⁻² · s⁻¹ (A), and 4.2 × 10¹⁵ photons · cm⁻² · s⁻¹ (B).