Publications by authors named "J Girardie"

Interaction with the environment appears necessary for the maturation of sensorimotor and cognitive functions in early life. In rats, a model of sensorimotor restriction (SMR) from postnatal day 1 (P1) to P28 has shown that low and atypical sensorimotor activities induced the perturbation of motor behavior due to muscle weakness and the functional disorganization of the primary somatosensory and motor cortices. In the present study, our objective was to understand how SMR affects the muscle-brain dialogue.

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To complete previous results concerning the role of the ovary maturating parsin of Locusta migratoria (Lom OMP), we determined, by an enzyme immunoassay, the titers of circulating ecdysteroids and analyzed circulating vitellogenin (Vg) and oöcyte growth following (1) suppression of 20 hydroxyecdysone (20E) and (2) injection of the Lom OMP, either as an entire molecule in allatectomized adults or as smaller peptides in allatectomized fifth-instar larvae females. Titers of ecdysteroids appeared unrelated to the presence of circulating Vg but increased during the first phase of vitellogenesis and injection of OMP accelerated the occurrence of circulating 20E. Nevertheless, immunoneutralization of 20E at the beginning of adult life delayed but did not prevent rapid oöcyte growth contrary to immunoneutralization of Lom OMP suggesting an additive gonadotropic effect of the neurohormone, distinct from that of 20E.

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Neuroparsins were originally identified in locust corpus cardiacum extracts as folliculostatic or 'antigonadotropic' neuropeptides. This paper presents the cloning of two different neuroparsin precursor cDNAs from the brain of the desert locust, Schistocerca gregaria. The first transcript encodes the precursor (Scg-NPP1) of S.

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Neurosecretory products immunologically related to either neuroparsin (NP) or ovary maturing parsin (OMP) of Locusta migratoria (Lom) were purified from the nervous corpora cardiaca of Schistocerca gregaria (Scg). The determination of both their molecular masses by mass spectrometry and their sequences by automated Edman degradation established that they are members of the NP and OMP families respectively. NP molecules of Schistocerca (Scg NPs) consisted of two major forms having about the same molecular masses as NPA and NPB of Locusta and 88% primary structure similarity.

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The cDNA encoding neuroparsin A, a polytropic neurohormone of the locust, Locusta migratoria, was inserted into the genome of Autographa californica nuclear polyhedrosis virus such that transcription was under control of the p10 promoter. A polypeptide having the same charge and the same apparent molecular weight as the authentic neuroparsin A and that was reactive against neuroparsin immune serum was produced in recombinant virus-infected lepidopteran cell lines but not in control virus-infected cells. The baculovirus-expressed polypeptide was purified by two steps of liquid chromatography (anion exchange and reversed phase) which were previously used to purify the natural neuroparsin.

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