Cortisone sensitive T-cells in Peyer's patches

Summary Pretreatment of donor lymphoid cells with cortisone has been shown to depress the T-cell subpopulation responsible for cellular proliferation in the GVH reaction. A quantitative assay as well as the histological criteria of the GVH reaction have been used in this study to demonstrate the presence of cortisone-sensitive T-cells within the Peyer's patches as well as in the spleen and mesenteric lymph nodes in the rat.This work was supported by a grant of the Délégation Générale à la Recherche Scientifique et Technique (No. 74-7-0619).     

Subpopulations of T-lymphocytes in Peyer's patches: Sensitivity to antilymphocyte serum and adult thymectomy

Summary Anti-lymphocyte (ALS) treatment or adult thymectomy of the donor have been shown to depress respectively the cell proliferation and the cytotoxicity in the graft-versus-host (GVH) reaction. A quantitative assay and the histological criteria of the GVH reaction have been used to demonstrate that all the known subpopulations of T-lymphocytes involved in the GVH reaction are present in the Peyer's patches as well as in the spleen and mesenteric lymph nodes in the rat.This work was supported by a grant of the Délégation Générale à la Recherche Scientifique et Technique (No. 74-7-0619).     

Wnt and lithium: a common destiny in the therapy of nervous system pathologies?

Wnt signaling is required for neurogenesis, the fate of neural progenitors, the formation of neuronal circuits during development, neuron positioning and polarization, axon and dendrite development and finally for synaptogenesis. This signaling pathway is also implicated in the generation and differentiation of glial cells. In this review, we describe the mechanisms of action of Wnt signaling pathways and their implication in the development and correct functioning of the nervous system. We also illustrate how a dysregulated Wnt pathway could lead to psychiatric, neurodegenerative and demyelinating pathologies. Lithium, used for the treatment of bipolar disease, inhibits GSK3β, a central enzyme of the Wnt/β-catenin pathway. Thus, lithium could, to some extent, mimic Wnt pathway. We highlight the possible dialogue between lithium therapy and modulation of Wnt pathway in the treatment of the diseases of the nervous system.     

Encoding of conditioned fear in central amygdala inhibitory circuits

The central amygdala (CEA), a nucleus predominantly composed of GABAergic inhibitory neurons, is essential for fear conditioning. How the acquisition and expression of conditioned fear are encoded within CEA inhibitory circuits is not understood. Using in vivo electrophysiological, optogenetic and pharmacological approaches in mice, we show that neuronal activity in the lateral subdivision of the central amygdala (CEl) is required for fear acquisition, whereas conditioned fear responses are driven by output neurons in the medial subdivision (CEm). Functional circuit analysis revealed that inhibitory CEA microcircuits are highly organized and that cell-type-specific plasticity of phasic and tonic activity in the CEl to CEm pathway may gate fear expression and regulate fear generalization. Our results define the functional architecture of CEA microcircuits and their role in the acquisition and regulation of conditioned fear behaviour.     

Effect of vinblastine on pancreatic enzymes secretion induced by cyclic nucleotide derivatives

Summary Vinblastine did not affect the basal secretion of enzymes from the rat pancreas, but it potentiates the secretory response to dibutyryl cyclic AMP. This potentiation is confirmed by the observation of numerous pictures of exocytosis at the apical part of the acinar cell. Dibutyryl cyclic GMP by itself, or associated with vinblastine, failed to modify the spontaneous release of enzymes or the secretion induced by dibutyryl cyclic AMP.This work was supported by the Institut National de la Santé et de la Recherche Médicale (France).     

Effect of vinblastine on pancreatic enzymes secretion induced by cyclic nucleotide derivatives.

Vinblastine did not affect the basal secretion of enzymes from the rat pancreas, but it potentiates the secretory response to dibutyryl cyclic AMP. This potentiation is confirmed by the observation of numerous pictures of exocytosis at the apical part of the acinar cell. Dibutyryl cyclic GMP by itself, or associated with vinblastine, failed to modify the spontaneous release of enzymes or the secretion induced by dibutyryl cyclic AMP.     

Cortisone sensitive T-cells in Peyers' patches.

Pretreatment of donor lymphoid cells with cortisone has been shown to depress the T-cell subpopulation responsible for cellular proliferation in the GVH reaction. A quantitative assay as well as the histological criteria of the GVH reaction have been used in this study to demonstrate the presence of cortisone-sensitive T-cells within the Peyer's patches as well as in the spleen and mesenteric lymph nodes in the rat.     

Subpopulations of T-lymphocytes in Peyer's patches: sensitivity to antilymphocyte serum and adult thymectomy.

Anti-lymphocyte (ALS) treatment or adult thymectomy of the donor have been shown to depress respectively the cell proliferation and the cytotoxicity in the graft-versus-host (GVH) reaction. A quantitative assay and the histological criteria of the GVH reaction have been used to demonstrate that all the known subpopulations of T-lymphocytes involved in the GVH reaction are present in the Peyer's patches as well as in the spleen and mesenteric lymph nodes in the rat.