Fig. 8 a in Early ant trajectories: spatial behaviour before behaviourism

Fig. 8 a In 1967 Wolfgang Goll provided the first study in which Ramón y Cajal'sfavorite method,the silverchromate (Golgi) impregnation, was successfully applied in an ant's brain. The figure reproduces Goll's reconstruction of part of the central complex of the wood ant, Formica rufa. Abbreviations dors., dorsal; ZKo and ZKu, Zentralkörper oberer and unterer Teil (fan-shaped body and ellipsoid body), respectively. The Golgi impregnated neurons depict tangential cells of the upper and lower unit of the central complex.The tangential cell in the lower unit exhibits only six rather than the usual eight dendritic columns meaning that either the staining has been incomplete or that two lateral columns have been located in an adjacent section not used for the drawing. In their extensive work on the central complex of locusts, Uwe Homberg and his collaborators have characterized comparable neurons anatomically (e.g., by LuciferYellow staining) and neurophysiologically: for the tangential cells in the upper and lower unit, see Homberg (1994, Fig. 6) and Müller et al. (1997, Fig. 3), respectively. b Since Goll's work it was only in 1995 that Wulfila Gronenberg from the University of Arizona at Tucson succeeded in Golgi-staining neurons in the forebrain (protocerebrum) of ants.The hitherto unpublished figure depicts three Kenyon cells in the mushroom body of Camponotus castaneus. The Golgi impregnated neurons correspond to the "spiny lip Kenyon cells (type KI)" described by Peter G. Mobbs in honeybees (Mobbs 1982). Courtesy ofWulfila Gronenberg