SICB Division of Invertebrate Zoology (DIZ)

DIZ Researchers Database Entry

Megumi Fuse

Insect Physiology and Neuropeptides
I study the neural regulation of a complex behavior; namely ecdysis, or the shedding of the outer cuticle, in insects. I am identifying new peptides and their actions in ecdysis, along with the signal transduction mechanisms involved. I have also identified an inhibitory input that may be a key element in timing ecdysis behaviors in many, if not all insects. This inhibition may provide different insects (with different body shapes and habitats) the flexibility to shed their cuticles at appropriate times of day, or in appropriate lengths of time. This response is part of a network that I anticipate will be a general model system for studying neural modulation and control of the central nervous system in all animals.

The above photo is an abdominal ganglion (part of the central nervous system) of the hornworm, Manduca sexta, using double labeled fluorescent immunohistochemistry. The double label is of (i) cGMP (in activated neurons involved in regulating ecdysis) in green - fitc stain - and (ii) FMRFamide-like peptides (a family of small neuropeptides) in red - texas red stain. The animal was undergoing ecdysis when the nervous system was dissected and fixed for immunohistochemistry. This figure shows that FMRFamide-like peptides were not localized in the cGMP-stained neurons (some of which are known to contain Crustacean Cardioactive Peptide). This photo is taken from Fuse and Truman (2002). J. Exp. Biol. 205: 1047-1058.