Rewarded associative and instrumental conditioning after neonatal ventral hippocampus lesions in rats

Sprague Dawley rats were submitted to bilateral ventral hippocampus lesions 7 days after birth. This corresponds to the Lipska and Weinberger`s procedure for modeling schizophrenia. The aim of the present work was to test the learning capacity of such rats with an associative Pavlovian and an instrumental learning paradigm, both methods using reward outcome (food, sucrose or polycose). The associative paradigm comprised also a second learning test with reversed learning contingencies. The instrumental conditioning comprised an extinction test under outcome devaluation conditions. Neonatally lesioned rats, once adults (over 60 days of age), showed a conditioning deficit in the associative paradigm but not in the instrumental one. Lesioned rats remained able to adapt as readily as controls to the reversed learning contingency and were as sensitive as controls to the devaluation of outcome. Such observations indicate that the active access (instrumental learning) to a reward could have compensated for the deficit observed under the ""passive"" stimulus-reward associative learning condition. This feature is compared to the memory management impairments observed in clinical patients. (c) 2008 Elsevier B.V. All rights reserved

MRI and X-ray scanning images of the brain of 3-, 6- and 9-month-old rats with bilateral neonatal ventral hippocampus lesions

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Public jeune : son avis, ses attentes (Le)

Table ronde organisée dans le cadre des Rencontres Henri-Jean Martin 2015 : Le patrimoine #tropdelaballe. Avec la participation de : - Chantal Dahan (chargée d’études et de recherche – Observatoire de la jeunesse et des politiques de jeunesse). - Jocelyne Deschaux (directrice du réseau des médiathèques du Grand Albigeois). - Marie Évreux (chargée de médiation culturelle - Opéra de Lyon). - Anne-Marine Guiberteau (chargée de la programmation jeune public et des actions de médiation – Centre Pompidou-Metz). Modération : Thierry Claerr (chef du Bureau de la lecture publique – ministère de la Culture et de la Communication)

Débat avec André Dumas, Paul Guiberteau, Pierre Jacquet, Claude-François Jullien et Thierry de Montbrial

Dumas André, Guiberteau Paul, Jacquet Pierre, Jullien Claude-François, De MONTBRIAL Thierry. Débat avec André Dumas, Paul Guiberteau, Pierre Jacquet, Claude-François Jullien et Thierry de Montbrial. In: Autres Temps. Les cahiers du christianisme social. N°38, 1993. pp. 85-96

Acoustic hypersensitivity in adult rats after neonatal ventral hippocampus lesions

International audienceThis study aimed at evaluating the performance of an intraoperative gamma camera, named CarolIReS, to detect axillary drainage and to assess the removal of sentinel lymph nodes (SLN) in breast surgery

Aromatic-Based Design of Highly Active and Noncalcemic Vitamin D Receptor Agonists

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Design, Synthesis, Biological Activity, and Structural Analysis of Novel Des-C-Ring and Aromatic-D-Ring Analogues of 1α,25-Dihydroxyvitamin D 3

International audienceThe toxic calcemic effects of the natural hormone 1α,25-dihydroxyvitamin D3 (1,25D3, 1,25-dihydroxycholecalciferol) in the treatment of hyperproliferative diseases demand the development of highly active and noncalcemic vitamin D analogues. We report the development of two highly active and noncalcemic analogues of 1,25D3 that lack the C-ring and possess an mphenylene ring that replaces the natural D-ring. The new analogues (3a, 3b) are characterized by an additional six-carbon hydroxylated side chain attached either to the aromatic nucleus or to the triene system. Both compounds were synthesized by the Pd-catalyzed tandem cyclization/cross coupling approach starting from alkyne 6 and diphenol 8. Key steps include a stereoselective Cu-assisted addition of a Grignard reagent to an aromatic alkyne and a Takai olefination of an aromatic aldehyde. The new compounds are noncalcemic and show transcriptional and antiproliferative activities similar to 1,25D3. Structural analysis revealed that they induce a large conformational rearrangement of the vitamin D receptor around helix 6

Aromatic-Based Design of Highly Active and Noncalcemic Vitamin D Receptor Agonists

We report the design, synthesis, biological evaluation, and structural analysis of a new class of vitamin D analogues that possess an aromatic <i>m</i>-phenylene <b>D</b>-ring and an alkyl chain replacing the <b>C</b>-ring. A key feature of the synthetic strategy is a stereoselective Pd-catalyzed construction of the triene system in aqueous medium that allows the rapid preparation of small amounts of VDR ligands for biological screening. Analogues with the shorter (<b>2a</b>) and longer (<b>2d</b>, <b>2e</b>) side chains attached to the triene system have no calcemic activity. Compound <b>2a</b> binds to VDR with the same order of magnitude than calcipotriol and oxacalcitriol. It also reduces proliferation in normal and tumor cells similarly to the natural hormone 1α,25-dihydroxyvitamin D₃, calcipotriol, and oxacalcitriol, suggesting preclinical studies related to hyperproliferative disorders such as psoriasis and cancer