Mapping of serotonin-immunoreactive neurons of Anastrepha obJiqua Macquart larvae

Serotonin-immunoreactive neurons were identified in the central nervous system (CNS) of Anaslrepha obliquo Macqualt, 1835 wandering stage larvae. The PAP immunocytochemical method was applied to the entire CNS (whole mounts). About 90 neurons were visualized in the CNS (20 in the brain and 70 in the ventral ganglion). Both somata and axons were strongly stained. These neurons showed a segmental arrangement and bilateral symmetry. All processes presented a basic projection pattern, in which the major fibres travel contra laterally. Comparison of these neurons with serotonergic neurons described in other insects suggests order-specific traits such as cerebral clusters and presence of only one 5-HT immunoreactive neuron in the 8 abdominal neuromere as well.