Abstract
Retrograde l ling with long chain fluorescent dyes DiIC16 is used to localize brain neurosecretory cells that may be involved in the regulation of corpora allata (CA), from which juvenile hormone is secreted. The fluoresent probe was microinjected into CA of drosophila ring gland and transported by membrane fluidity of neurons, backward to the brain after 12 hours in living tissue at room temperature or after 2 hours in fixed tissue at 45℃. Three-dimensional distribution of l led neurons was analyzed and reconstructed with confocal microscopy.The results show that neurons extended to CA may be classified into four groups including MNSC (medial neurosecretory cells), LNSC (lateral neurosecretory cells), TNSC (tritocerebral neurosecretory cells), and SGNSC (Subesophageal ganglion neurosecretory cells). All these neurosecretory cells were symmetrically distribute and both NCCI (nervi corpotis cardiaci I) and NCCII (nervi corporis cardiaci II) pathways were clearly stained. Results of current study will have great impact on our understanding of how the brain neurons control the development and function of the ring gland.