Postembryonic development of γ‐aminobutyric acid‐like Immunoreactivity in the brain of the sphinx moth Manduca sexta

摘要: We have investigated the distribution of immunocytochemical staining for neurotransmitter γ-aminobutyric acid (GABA) in brain sphinx moth Manduca sexta during larval, pupal, and adult development. In larval brain, about 300 neurons are GABA-immunoreactive. All neuropil areas except mushroom bodies central complex show intense immunostaining. Only minor changes pattern immunoreactivity occur During metamorphosis, immunostaining two phases. Beginning wandering fifth-instar larvae (stage W2), appears numerous body optic lobe becomes more early pupal stages. At same time, GABA-like disappears most faint many immunoreactive somata. Neurons with arborizations ventrolateral protocerebrum, however, continue to exhibit this period, strongly immunolabeled fibers connect these ventral nerve cord. The second phase transformation begins around stage P5/P6, when previously nonimmunoreactive somata brain. subsequent stages (P8–P10), again somata, but certain cell groups, it gradually develops pattern. Most GABA-immunoreactive appear survive through metamorphosis into adult. midbrain that acquire usually lie adjacent immunostained neurons, suggesting common lineages. onsets developmental phases correlate sharp rises hemolymph titers ecdysteroid hormones, a role ecdysteroids regulation GABA synthesis. hypothesize disappearance starting 2 days prior pupation dramatically alters its functional circuitry thus may account profound behavior animal. © 1994 Wiley-Liss, Inc.