Marking and recording of monopolar cells in the bee lamina

Monopolar cells in the lamina ganglionaris of the honeybee, Apis mellifera, were marked individually for the first time and intracellular recordings made. The electrophysiological responses were mainly hyperpolarizing with peaks and descending plateaux; one specific cell gave depolarizing responses, sustained in UV, and phasic at other wavelengths. Spectral sensitivity curves obtained by the spectral scanning method showed maximum sensitivity at 520 nm. Three morphological cell types were encountered, all of which differ considerably from those described by Ribi (1).