Denervation supersensitivity to serotonin in rat forebrain: Single cell studies

To investigate the development of denervation supersensitivity to serotonin (5-hydroxytryptamine, 5-HT) in the amygdala (AMYG) and the ventral lateral geniculate nucleus (vLGN), single cell recordings, microiontophoretic, histochemical and biochemical techniques were used in the present study. 5-HT projections to the vLGN and the AMYG were destroyed by 5,7-dihydroxytryptamine (5,7-DHT, a relatively selective toxin for 5-HT neurons) injected directly into the lateral ventricle or the ascending 5-HT pathway in the ventromedial tegmentum area. Enhanced responsiveness of cells to the inhibitory effect of microiontophoretically applied 5-HT (ionto-5-HT) began to develop within 24 h and approached a maximum 7 days after 5,7-DHT pretreatment. In general, the time courses for the reduction in both the density of 5-HT fluorescent varicosities and synaptosomal 5-HT uptake activity paralleled the time course for the development of denervation supersensitivity to 5-HT. During the first 2 days after 5,7-DHT, the enhanced sensitivity was selective for 5-HT; responses to D-lysergic acid diethylamide (LSD), norepinephrine (NE) and gamma-aminobutyric acid (GABA) were unchanged. Seven or more days after 5,7-DHT there was a marked increase of the responsiveness of neurons in the vLGN and the AMYG to both 5-HT and LSD (a 5-HT agonist which is not a substrate for the high affinity 5-HT uptake system). At these later times, the responsiveness of cells in the AMYG to NE and to a lesser extent GABA was also increased. In contrast to the marked supersensitivity seen after 5,7-DHT induced denervation, chronic administration of parachlorophenylalanine, a 5-HT synthesis inhibitor, failed to induce 5-HT supersensitivity.     

Build-up with Antigen Absorption Test

An antigen absorption test using anti-A serum and A substance is described.
Using a build-up technique with the antigen absorption test, visual agglutination of formerly inagglutinable A cells, including a mixed-field appearance, has been obtained by both anti-A sera of human origin and Dolichos biflorus extract.

Résumé

Les auteurs décrivent un test d'absorption d'antigènes dans lequel ils ont utilisé un sérum anti-A et de la substance A.
Pour pratiquer ce test d'absorption, ils ont mis au point une technique basée sur le principe des réactions en chaîne grâce à laquelle ils ont pu obtenir avec des sérums anti-A d'origine humaine et un extrait de dolichos biflorus des agglutinations, présentant souvent l'image de l'agglutination mixte, d'érythrocytes A initialement inagglutinables.

Zusammenfassung

Es wird ein Antigen-Absorptionstest mit Anti-A-Serum und A-Gruppensubstanz beschrieben. Dieser Test wurde verwendet, um mit einer Mehrphasentechnik nicht agglutinierbare A-Zellen zu agglutinieren. Dies gelang sowohl mit menschlichen Anti-A-Seren als auch mit Dolichos-biflorus-Extrakten, wobei Mischzellbilder beobachtet wurden.     

Regulation of appetite and cholecystokinin secretion in anorexia nervosa.

Six patients with anorexia nervosa, the same patients after weight normalization, and six healthy control subjects had similar fasting and postprandial plasma cholecystokinin concentrations. These data do not support the hypothesis that low levels of hunger and food intake in anorexic patients reflect hypersecretion of this endogenous hormone, which is thought to inhibit hunger, promote satiety, and reduce feeding.     

Differential regulation of T helper phenotype development by interleukins 4 and 10 in an alpha beta T-cell-receptor transgenic system.

To address the mechanisms controlling T helper (Th) phenotype development, we used DO10, a transgenic mouse line that expresses the alpha beta T-cell receptor from an ovalbumin-reactive T hybridoma, as a source of naive T cells that can be stimulated in vitro with ovalbumin peptide presented by defined antigen-presenting cells (APCs). We have examined the role of cytokines and APCs in the regulation of Th phenotype development. Interleukin 4 (IL-4) directs development toward the Th2 phenotype, stimulating IL-4 and silencing IL-2 and interferon gamma production in developing T cells. Splenic APCs direct development toward the Th1 phenotype when endogenous IL-10 is neutralized with anti-IL-10 antibody. The splenic APCs mediating these effects are probably macrophages or dendritic cells and not B cells, since IL-10 is incapable of affecting Th phenotype development when the B-cell hybridoma TA3 is used as the APC. These results suggest that early regulation of IL-4 and IL-10 in a developing immune response and the identity of the initiating APCs are critical in determining the Th phenotype of the developing T cells.