The numerical, locational and structural changes of the neurons reacting with an antiserum raised against a neuropeptide, locustatachykinin-I (Lom TK I) were investigated in the ventral ganglia of the common cutworm, Spodoptera litura, during postembr...
The numerical, locational and structural changes of the neurons reacting with an antiserum raised against a neuropeptide, locustatachykinin-I (Lom TK I) were investigated in the ventral ganglia of the common cutworm, Spodoptera litura, during postembryonic development. In the first instar larva, one pair of the Lom TK I- immunoreactive (Lom TK I-IR) neurons are included only in the mesothoracic ganglion of the ventral nerve cord. In the second instar larva, suboesophageal, prothoracic, mesothoracic, metathoracic, and sixth abdominal ganglia contain about 2 to 14 Lom TK I- IR neurons, while all the ganglia of the ventral nerve cord in the third instar larva have increased number of the Lom TK I- IR neurons. Each ganglion of the fourth, fifth and sixth instar larvae includes the largest number of the Lom TK I- IR neurons. Thereafter, however, smaller number of the Lom TK I- IR neurons are included in each ganglion than in late larval stages. Most of the Lom TK I- IR neurons show bilateral localization in each ganglion during postembryonic development, whereas extremly small number of the Lom TK I-IR neurons are unpaired, median neurons in all metathoracic ganglia from the second instar larva to the adult, and the fifth abdominal ganglia of the 3- day- old pupa to the adult. Most of the Lom TK I-IR neurons sre the interneurons, while part of them are afferent or efferent. The extrinsic Lom TK I- IR fibers form two pairs of longitudinal fiber tracts in the ventral nerve cord, especially in each ventral ganglion. The Lom TK I- IR fibers projected from the neurons in various ventral ganglia form the commissural structures between neuropil both sides.