Fig. 7.
Ultrastructural immunocytochemical evidence for mast cell-derived gonadotropin-releasing hormone (GnRH) in neurons. (A) 3,3′ diaminobenzidine (DAB), used to detect sites of antibody binding, forms a flocculent deposit (which can obscure finer ultrastructural detail) in some (white arrow) but not all granules within the mast cell. DAB deposits are also present in two adjacent neurons (N1 and N2; arrowheads). There are multiple layers of mast cell filopodia cut in both longitudinal and cross section (double arrows). Some of these are associated with DAB deposits (long arrows). (B) In this plane of section the mast cell (MC) has few granules. Within the neuron (N), small deposits of immunoreactive material are found associated with vesicles (arrows). Some of these vesicles are close to the Golgi apparatus (g). DAB is also associated with the surface of filopodia (arrowhead). Double arrows indicate the characteristic multiple filopodial layers of the MC.