Abstract
Corpora allata, a pair of the endocrine glands, synthesize and release juvenile hormone (JH) to regulate the development and reproduction of insects. Recently, roles of contralateral pars intercerebralis (PI) and ipsilateral pars lateralis (PL) neurons were investigated. However, how was the mating signal transduced from those neurons to corpus allatum (CA) is still ambiguous. In this study, by using the retrograde l lling, 3D confocal microscopy and computer processing, the complete neuronal network with axons innervating on CA and dendritic arborization on the mushroom body a lobe was mapped in the brain of cockroach, Diploptera punctata. The roles of PI and PL neurons in the transduction of mating signals were investigated following image-guided ablation. I found that removal of PL neurons but not PI neurons resulted in activation of the corpora allata in virgin females, suggesting a pivotal role in inhibiting the JH biosynthesis and mitotic activity of CA. Since the PL removal in mated females which PI neurons were activated by mating signals could lead to the prolonged mitotic activity, these data indicated the cooperation of PI and PL neurons in inducing cell proliferation after mating might exist. And the lesions on mushroom bodies resulted in immature oocyte growth that evidenced the mating signal might be processed by the intact mushroom body and then transferred from a lobe to PI and PL neurons. Finally, the data developed a working hypothesis to describe the relationship among the mating signaling, the function of the mushroom body and roles of PI and PL neurons in D. punctata.