26 research outputs found
Differential regulation of neurexin at glutamatergic and GABAergic synapses
Neurexins (Nrxs) have emerged as potential determinants of synaptic specificity, but little is known about their localization at central synapses. Here we show that Nrxs have a remarkably selective localization at distinct types of glutamatergic synapses and we reveal an unexpected ontogenetic regulation of Nrx expression at GABAergic synapses. Our data indicate that synapses are specified by molecular interactions that involve both Nrx-dependent and Nrx-independent mechanisms. We propose that differences in the spatio-temporal profile of Nrx expression may contribute to specify the molecular identity of synapses
Estudios de prospectiva en educaciĂłn. Diversidad, inclusiĂłn y aprendizaje
Fil: Ferreyra, Horacio Ademar. Universidad CatĂłlica de CĂłrdoba. Facultad de EducaciĂłn; ArgentinaFil: PĂ©rez Moreno, Elena Silvia. Universidad CatĂłlica de CĂłrdoba. Facultad de EducaciĂłn; ArgentinaFil: PellizĂłn, Telma de Lourdes, Universidad CatĂłlica de CĂłrdoba. Facultad de EducaciĂłn; Argentin
In vitro characterization of lactic acid bacteria isolated from bovine milk as potential probiotic strains to prevent bovine mastitis
Bovine mastitis causes economic losses on dairy farms worldwide. Lactic acid bacteria (LAB) in animal health are an alternative tool to avoid antibiotic therapy on the prevention of bovine mastitis. In previous studies, 12 LAB isolated from bovine milk were selected taking into account some of the following characteristics: hydrophobicity, auto aggregative capability, inhibition of indicator pathogens, hydrogen peroxide, and capsular polysaccharide production. These LAB were considered because of their beneficial properties. In this work, we also analyzed the antimicrobial activity and the co-aggregation against mastitis causing bacteria, auto-inhibition, adhesion to bovine teat canal epithelial cells (BTCEC), and growth kinetic curves for the 12 LAB. Two of them, Lactococcus lactis subsp. lactis CRL 1655 and Lactobacillus perolens CRL 1724, were selected because they had an interesting pattern of adhesion to BTEC, the inhibition of pathogens and the co-aggregation with the 100% of the assayed pathogens. They showed a predictable difference in the PFGE genomic pattern bands. The kinetic growth of these two strains was similar between them and with the rest of the assayed LAB. The strains selected in the present study showed indispensable characteristics for their inclusion in a probiotic formulation to be used at dry-off period for the prevention of bovine mastitis.Fil: Pellegrino, Matias Santiago. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba; Argentina. Universidad Nacional de RĂo Cuarto. Facultad de Ciencias Exactas, FisicoquĂmicas y Naturales. Departamento de MicrobiologĂa e InmunologĂa; ArgentinaFil: Frola, Ignacio Daniel. Universidad Nacional de RĂo Cuarto. Facultad de Ciencias Exactas, FisicoquĂmicas y Naturales. Departamento de MicrobiologĂa e InmunologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba; ArgentinaFil: Berardo, Natanael. Universidad Nacional de RĂo Cuarto. Facultad de Ciencias Exactas, FisicoquĂmicas y Naturales. Departamento de MicrobiologĂa e InmunologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba; ArgentinaFil: Gobelli, Dino Joaquin. Universidad Nacional de RĂo Cuarto. Facultad de Ciencias Exactas, FisicoquĂmicas y Naturales. Departamento de MicrobiologĂa e InmunologĂa; ArgentinaFil: Nader, Maria Elena Fatima. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - TucumĂĄn. Centro de Referencia para Lactobacilos; ArgentinaFil: Bogni, Cristina Ines. Universidad Nacional de RĂo Cuarto. Facultad de Ciencias Exactas, FisicoquĂmicas y Naturales. Departamento de MicrobiologĂa e InmunologĂa; Argentin
Synaptic competition sculpts the development of GABAergic axo-dendritic but not perisomatic synapses.
The neurotransmitter GABA regulates many aspects of inhibitory synapse development. We tested the hypothesis that GABAA receptors (GABAARs) work together with the synaptic adhesion molecule neuroligin 2 (NL2) to regulate synapse formation in different subcellular compartments. We investigated mice ("Îł2 knockdown mice") with an engineered allele of the GABAAR Îł2 subunit gene which produced a mosaic expression of synaptic GABAARs in neighboring neurons, causing a strong imbalance in synaptic inhibition. Deletion of the Îł2 subunit did not abolish synapse formation or the targeting of NL2 to distinct types of perisomatic and axo-dendritic contacts. Thus synaptic localization of NL2 does not require synaptic GABAARs. However, loss of the Îł2 subunit caused a selective decrease in the number of axo-dendritic synapses on cerebellar Purkinje cells and cortical pyramidal neurons, whereas perisomatic synapses were not significantly affected. Notably, Îł2-positive cells had increased axo-dendritic innervation compared with both Îł2-negative and wild-type counterparts. Moreover heterologous synapses on spines, that are found after total deletion of GABAARs from all Purkinje cells, were rare in cerebella of Îł2 knockdown mice. These findings reveal a selective role of Îł2 subunit-containing GABAARs in regulating synapse development in distinct subcellular compartments, and support the hypothesis that the refinement of axo-dendritic synapses is regulated by activity-dependent competition between neighboring neurons
Histological examination of non-lactating bovine udders inoculated with Lactobacillus perolens CRL 1724
The effect of intramammary inoculation of Lactobacillus perolens CRL 1724 on bovine udders at drying off was evaluated through histological examination of the canal and cistern tissues. The persistence of the strain in the udder 7 d post inoculation was also determined. Lb. perolens CRL 1724 was recovered from all mammary quarters and no clinical signs or teat damage were observed after inoculation of 106 cfu/ml. The udders showed a normal structural aspect and there were no modifications of the milk appearance. Lb. perolens CRL 1724 cells were evidenced on the surface of the epithelial cells of the cistern without causing any morphological modifications or cell alterations. Lb. perolens CRL 1724 produces a mild inflammatory reaction, characterized by recruitment of neutrophils to the epithelial zone and a slight hyperaemia into blood vessels. This preliminary study provides important information for further studies directed towards the inclusion of Lb. perolens CRL 1724 in the design of probiotic products for preventing bovine mastitis in non-lactating dairy cows.Fil: Frola, Ignacio Daniel. Universidad Nacional de RĂo Cuarto. Facultad de Ciencias Exactas, FisicoquĂmicas y Naturales. Departamento de MicrobiologĂa e InmunologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Pellegrino, Matias Santiago. Universidad Nacional de RĂo Cuarto. Facultad de Ciencias Exactas, FisicoquĂmicas y Naturales. Departamento de MicrobiologĂa e InmunologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Magnano, Gabriel. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de PatologĂa Animal; ArgentinaFil: Giraudo, Jose Angel. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de PatologĂa Animal; ArgentinaFil: Espeche, Maria Carolina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Nader, Maria Elena Fatima. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Bogni, Cristina Ines. Universidad Nacional de RĂo Cuarto. Facultad de Ciencias Exactas, FisicoquĂmicas y Naturales. Departamento de MicrobiologĂa e InmunologĂa; Argentin
Dystroglycan Mediates Clustering of Essential GABAergic Components in Cerebellar Purkinje Cells
International audienceMuscle dystrophin-glycoprotein complex (DGC) links the intracellular cytoskeleton to the extracellular matrix. In neurons, dystroglycan and dystrophin, two major components of the DGC, localize in a subset of GABAergic synapses, where their function is unclear. Here we used mouse models to analyze the specific role of the DGC in the organization and function of inhibitory synapses. Loss of full-length dystrophin in mdx mice resulted in a selective depletion of the transmembrane ÎČ-dystroglycan isoform from inhibitory post-synaptic sites in cerebellar Purkinje cells. Remarkably, there were no differences in the synaptic distribution of the extracellular α-dystroglycan subunit, of GABAA receptors and neuroligin 2. In contrast, conditional deletion of the dystroglycan gene from Purkinje cells caused a disruption of the DGC and severely impaired post-synaptic clustering of neuroligin 2, GABAA receptors and scaffolding proteins. Accordingly, whole-cell patch-clamp analysis revealed a significant reduction in the frequency and amplitude of spontaneous IPSCs recorded from Purkinje cells. In the long-term, deletion of dystroglycan resulted in a significant decrease of GABAergic innervation of Purkinje cells and caused an impairment of motor learning functions. These results show that dystroglycan is an essential synaptic organizer at GABAergic synapses in Purkinje cells