Because leucokinins stimulate diuresis in some insects, we wished to identify the neurosecretory cells in Manduca sexta that might be a source of leucokinin-like neurohormones. Immunostaining was done at various stages of development, using an antiserum to leucokinin IV. Bilateral pairs of neurosecretory cells in abdominal ganglia 3-7 of larvae and adults are immunoreactive; these cells project via the ipsilateral ventral nerves to the neurohemal transverse nerves. The immunoreactivity and size of these lateral cells greatly increases in the pharate adult, and this change appears to be related to a period of intensive diuresis occurring a few days before adult eclosion. Relationships of these neurons to cells that are immunoreactive to a M. sexta diuretic hormone were also investigated. Diuretic hormone and leucokinin immunoreactivity are co-localized in the lateral neurosecretory cells and their neurohemal projections. A median pair of leucokinin-immunoreactive, and a lateral pair of diuretic hormone-immunoreactive neurons in the larval terminal abdominal ganglion project to neurohemal release sites within the cryptonephridium. The immunoreactivity of these cells is lost as the cryptonephridium is eliminated during metamorphosis. This loss appears to be related to the change from the larval to adult pattern of diuresis.
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Talanta
January 2025
Department of Pharmaceutical Analysis, Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Faculty of Pharmacy, Fujian Medical University, Fuzhou, 350122, China. Electronic address:
The rise of extracellular matrix (ECM)-supported three-dimensional (3D) cell culture systems which bridge the gap between in vitro culture and in vivo living tissue for pharmacological models has increased the need for simple and robust cell viability assays. This study presents the development of an effective biosensing assay for in situ monitoring of the catecholamine neurotransmitter exocytosis levels for cell viability assessment within complicated cell-encapsulated hydrogel milieu. Firstly, the biosensing assay demonstrated the distinction among four pheochromocytoma (PC12) cell lines with varying degrees of differentiation and the discrepancy in cellular neurosecretory capacity between two-dimensional (2D) monolayer and 3D agarose hydrogel culture conditions, accompanied by morphological distinctions.
View Article and Find Full Text PDFNat Commun
January 2025
The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China.
Thyroid
January 2025
National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, Maryland, USA.
Thyroid hormones (TH) play a key role in fetal brain development. While severe thyroid dysfunction, has been shown to cause neurodevelopmental and reproductive disorders, the rising levels of TH-disruptors in the environment in the past few decades have increased the need to assess effects of subclinical (mild) TH insufficiency during gestation. Since embryos do not produce their own TH before mid-gestation, early development processes rely on maternal production.
View Article and Find Full Text PDFMetab Brain Dis
December 2024
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View Article and Find Full Text PDFCell Tissue Res
December 2024
Department of Zoology, Stockholm University, S-10691, Stockholm, Sweden.
This review briefly summarizes 50 years of research on insect neuropeptide and peptide hormone (collectively abbreviated NPH) signaling, starting with the sequencing of proctolin in 1975. The first 25 years, before the sequencing of the Drosophila genome, were characterized by efforts to identify novel NPHs by biochemical means, mapping of their distribution in neurons, neurosecretory cells, and endocrine cells of the intestine. Functional studies of NPHs were predominantly dealing with hormonal aspects of peptides and many employed ex vivo assays.
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