Figure 1: Endogenous autofluorescence in lamprey brainstem after spinal cord injury. (A) Background autofluorescence in larval lamprey brain reticulospinal neurons under 465 nm excitation wavelength. Arrowheads point to neurons with autofluorescence. (B) The same brain area displays autofluorescence under 540 nm excitation wavelength. Arrowheads point to neurons with autofluorescence. (C) and (D) The nucleus of a lamprey brain neuron displaying strong, broad (465 nm - 540 nm) autofluorescence. White arrows point to the nucleus; white stars are in an area small, autofluorescent neurons/glial cells.