SYNDROME DE L’ARTERE POPLITEE PIEGEE : UNE CAUSE RARE DE CLAUDICATION INTERMITTENTE DU SUJET JEUNE

The syndrome of the trapped pop1ity artery appears in the young adult like a limping of the calf and or foot. Anatomical anomalies relating to insertions of the internai Twin muscle primarily. The diagnosis is suspect on Doppler echography, showing positional compression, change of direction of the poplitée artery, or only the existence of an abnormal fascicule of muscle fibres between artery and poplity vein. Angio IRM can replace the conventional assessment arteriographic. The treatment of extrinsic compression must avoid the constitution of parietal lesions and thromboses if they are installed, the suppression of the anatomical anomaly must be associated a segmentary revascularisation in autogenous venous material. Our patient is a young patient who consulted for an intermittent limping of effort of the right calf. The peripheral pulses were present, just as arterial the Doppler echo and the angio scanner of the hollow poplity showed the insertion of a beam of the internal  twin between the artery and the vein poplity. The arterial échodoppler and the IRM are according to certain authors the only essential examinations with the positive and differential diagnosis of the syndrome of the trapped pop1ity artery and will make it possible to eliminate from other differential diagnoses: pop1ity athéromating and the early athérome, disease of Burger or thromboangéite obliterating, the aneurisms poplities and the cysts adventitiels of the poplity artery. The treatment is always surgical and must be early. It includes/understands the lifting of the trap associated with the need with an arterial gesture of revascularisation. For the authors, the permeability to short and long-term was better for the patients among whom one practised a section of the musculo-tendineux beam being wrong compared to the patient which profited from a gesture of  vascular restoration.Le syndrome de l’artère poplitée piégée se manifeste chez l’adulte jeune comme une claudication du mollet et ou du pied. Les anomalies anatomiques concernant essentiellement les insertions du muscle Jumeau interne. Le diagnostic est suspecté sur l’échographie doppler, montrant la compression positionnelle, le changement de direction de l’artère poplitée, ou seulement l’existence d’un faisceau musculaire anormal entre artère et veine poplitée. L’angio IRM peut remplacer le bilan artériographique conventionnel. Le traitement de la compression extrinsèque doit éviter la constitution de lésions pariétales et de thromboses si elles sont installées, la suppression de l’anomalie anatomique doit être associée à une revascularisation segmentaire en matériel veineux autogène. Notre patient est un malade jeune qui a consulté pour une claudication intermittente d’effort du mollet droit. Les pouls périphérique étaient présents, de même que l’écho doppler artériel et l’angio scanner du creux poplité montraient l’insertion d’un faisceau du jumeau interne entre l’artère et la veine poplité. L’échodoppler artériel et l’IRM sont selon certains auteurs les seuls examens indispensables au diagnostic positif et différentiel du syndrome de l’artère poplitée piégée et vont permettre d’éliminer d’autres diagnostics différentiels : poplitée athéromateuse et l’athérome précoce, maladie de Buerger ou thromboangéite oblitérante, les anévrysmes poplités et les kystes adventitiels de l’artère poplitée. . Le traitement est toujours chirurgical et doit être précoce. Il comprend la levée du piège associé au besoin à un geste de revascularisation artériel. Pour les auteurs, la perméabilité a court et à long terme était meilleure pour les malades chez qui on a pratiqué une section du faisceau musculo-tendineux aberrant par rapport au patient qui ont bénéficié d’un geste de restauration vasculaire

Mesopontine rostromedial tegmental nucleus neurons projecting to the dorsal raphe and pedunculopontine tegmental nucleus: psychostimulant-elicited Fos expression and collateralization

The mesopontine rostromedial tegmental nucleus (RMTg) is a GABAergic structure in the ventral midbrain and rostral pons that, when activated, inhibits dopaminergic neurons in the ventral tegmental area and substantia nigra compacta. Additional strong outputs from the RMTg to the pedunculopontine tegmental nucleus pars dissipata, dorsal raphe nucleus, and the pontomedullary gigantocellular reticular formation were identified by anterograde tracing. RMTg neurons projecting to the ventral tegmental area express the immediate early gene Fos upon psychostimulant administration. The present study was undertaken to determine if neurons in the RMTg that project to the additional structures listed above also express Fos upon psychostimulant administration and, if so, whether single neurons in the RMTg project to more than one of these structures. We found that about 50% of RMTg neurons exhibiting retrograde labeling after injections of retrograde tracer in the dorsal raphe or pars dissipata of the pedunculopontine tegmental nucleus express Fos after acute methamphetamine exposure. Also, we observed that a significant number of RMTg neurons project both to the ventral tegmental area and one of these structures. In contrast, methamphetamine-elicited Fos expression was not observed in RMTg neurons labeled with retrograde tracer following injections into the pontomedullary reticular formation. The findings suggest that the RMTg is an integrative modulator of multiple rostrally projecting structures

Dopamine in the Medial Prefrontal Cortex Controls Genotype-Dependent Effects of Amphetamine on Mesoaccumbens Dopamine Release and Locomotion

Mice of background DBA/2J are hyporesponsive to the behavioral effects Of D-amphetamine in comparison with the widely exploited murine background C57BL/6J. In view of the important role of dopamine (DA) release in the nucleus accumbens (NAc) regarding the behavioral effects of psychostimulants, we tested the hypothesis of an inverse relationship between mesocortical and mesoaccumbens DA functioning in the two backgrounds. Systemic D-amphetamine induces a sustained increase in DA release in the medial prefrontal cortex (mpFC) accompanied by a poor increase in the NAc in mice of the low-responsive DBA/2J background, as shown by intracerebral microdialysis in freely moving animals. The opposite occurs in C57BL/6J mice, which show low prefrontal cortical DA outflow accompanied by high accumbal extracellular DA. Moreover, the DBA/2J background showed lower locomotor activity than C57BL/6J mice following D-amphetamine challenge. Selective DA depletion in the mpFC of DBA/2J mice produced a clear-cut increase in D-amphetamine-induced DA outflow in the NAc as well as locomotor activity that reached levels similar to those observed in C57BL/6J mice. Finally, local infusion of D-amphetamine by reverse microdialysis produced a similar increase in extracellular DA in both the mpFC and the NAc of DBA/2J mice. This finding points to similar transporter-related mechanisms in the two brain areas and supports the hypothesis that low accumbal DA release induced by systemic D-amphetamine in the DBA/2J background is determined by the inhibitory action of prefrontal cortical DA. The present results indicate that genotype-dependent susceptibility to addictive proper-ties of D-amphetamine involves unbalanced DA transmission in the mesocorticolimbic system

Amphetamine Exposure Selectively Enhances Hippocampus-Dependent Spatial Learning and Attenuates Amygdala-Dependent Cue Learning

Behaviorally sensitizing regimen of amphetamine (AMPH) exposure has diverse effects on learning, memory, and cognition that are likely to be a consequence of long-term neural adaptations occurring in the cortico-limbic-striatal circuitry. In particular, altered dopamine signaling in the nucleus accumbens and medial prefrontal cortex has been implicated to underlie AMPH-induced changes in behavior. This study sought to test the hypothesis that repeated AMPH exposure disrupts the regulation of limbic information processing and the balance of competing limbic control over appetitive behavior. Mice received seven intraperitoneal injections of D-AMPH (2.5 mg/kg or 5 mg/kg) or vehicle solution (saline) and were trained in (1) a simultaneous conditioned cue and place preference task using a six-arm radial maze, found to depend on the integrity of the hippocampus (HPC) and basolateral amygdala (BLA), respectively and (2) a conditional BLA-dependent cue, and HPC-dependent place learning task using an elevated T-maze. In both tasks, the vehicle pretreatment group initially acquired cue learning, followed by the emergence of significant place/spatial learning. In contrast, pretreatment with repeated AMPH caused marked deviations from normal acquisition patterns of place and cue conditioning, significantly facilitating HPC-dependent place conditioning in the first task while attenuating BLA-dependent cue conditioning in both tasks. These findings provide the first demonstration of an aberrant regulation of HPC- and BLA-dependent learning as a result of AMPH exposure, highlighting the importance of the meso-coticolimbic dopamine system in maintaining the balance of limbic control over appetitive behavior