Neuronal Architecture of the Visual System
The eye transforms the visual sphere into electrical signals in an array of neuronal channels. It is one of the appealing features of the arthropod brain that this property is immediately apparent in histological preparations. The orderliness of the compound eye as an array of identical subunits (ommatidia, visual elements) imposes itself upon the neuropil adjacent to it (Fig. 9). The optic lobe can be viewed as a two-dimensional neural crystal (Benzer, 1973). Neurocrystallinity is most apparent for the first and second neuropil regions (lamina and medulla) but a one-to-one relation between the visual elements in the eye and structural subunits in the neuropil has been established for all four regions (lamina, medulla, lobula, and lobula plate) (Power, 1943 b; for Musca see Braitenberg, 1970; 1972; Preißler, 1974; Strausfeld, 1976).
Unable to display preview. Download preview PDF.