Browsing by Subject "Synaptophysin"

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    Maternal exposure to the environmental pollutant "BDE-47" impairs the postnatal development of rat cerebellar cortex by modulating neuronal proliferation, synaptogenesis, NGF and BDNF pathways
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2022) Mandour, Dalia A.; Tolba, Asmaa M; El Bestawy, Emtethal M.
    . 2,2’,4,4’-Tetrabromodiphenyl ether (BDE47) is an environmental contaminant that crosses the blood placental barrier and interferes with the homeostasis of fetal thyroid hormones. Aim of work. This study was designed to investigate the perinatal effect of BDE-47 exposure on the postnatal development of the rat cerebellar cortex. Materials and methods. This study was carried out on 20 pregnant rats and 36 of their offspring. The pregnant rats were divided equally into control and BDE-47 treated mother groups; supplemented orally with BDE-47 (0.2 mg/kg/day from day 8 of gestation until the day of weaning). The offspring of both mother groups were subdivided, according to their developmental age, into three subgroups; PND14, PND21and PND42. SerumT3, T4 and TSH were assessed for dams and their offspring. Testing the motor coordination of the offspring via the rotarod test was conducted. Sections of the cerebellar cortex from offspring subgroups were stained with hematoxylin and eosin alongside immunohistochemical reactions and optical density of nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), proliferating cell nuclear antigen (PCNA) and synaptophysin (SYN) were assessed. Also, the thickness of different layers of the cerebellar cortex was histomorphometrically measured. Results. BDE-47 treated mothers and their offspring subgroups showed a significant decrease in the serum free T3, T4 and increased TSH. The BDE-47 offspring displayed incoordination of the motor activity together with disturbed cytoarchitecture of the cerebellar cortical layers, and impaired migration of its germinative neuronal zones, particularly on PND14 and PND21. Moreover, these offspring displayed a decrease of the immune-expression and optical density of NGF, BDNF in the cerebellar cortical layers with impaired proliferation, and synaptogenesis. Conclusion. Maternal exposure to BDE-47 during pregnancy and lactation effectuated a potential deleterious retarding effect on the postnatal development of the rat cerebellar cortex mostly via modulating neuronal proliferation, synaptogenesis, NGF and BDNF pathways secondary to its hypothyroid effect.
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    Synaptophysin immunoreactivity in the cat cochlear nuclei
    (Murcia : F. Hernández, 1998) Gil-Loyzaga, P.; Bartolome, M.V.; Ibanez, A.
    The presence of synaptophysin, a presynaptic ca2+ binding glycoprotein, has been analyzed in the cochlear nucleus complex of the adult cat using an antisynaptophysin monoclonal antibody. Synaptophysin immunoreactivity was differently distributed between regions of cochlear nuclei. Terminal boutons contacting directly with neurons (cell bodies and dendrites) or in the neuropil of ventral and dorsal cochlear nuclei appeared immunostained. In the ventral cochlear nucleus, synaptophysin-labelled boutons were clearly defined in contact with spherical, globular, multipolar, octopus and cochlear-nerve root neurons. However, the dorsal cochlear nucleus showed a dense immunostained network of synaptophysin-labelled puncta, inside which some neuron cell bodies were observed. The present findings show a differential distribution of synaptophysin- immunostained boutons between the ventral and the dorsal cochlear nuclei of the cat. The present description of the different synaptophysin-labelled terminal boutons in the cochlear nuclei complex and their pattern of distribution, will be useful for further studies on development, degeneration or regeneration of the peripheral auditory pathway.