19 research outputs found
Elaboration de nanoparticules d'oxydes MIEC : application au matériau de cathode Nd2NiO4
Comparaison des performances de la TEP au 18F-FDG et de la scintigraphie aux leucocytes marquĂ©s dans les infections de dispositifs dâassistance ventriculaire gauche
Comparison of the diagnostic performance and impact on management of 18F-FDG PET/CT and whole-body MRI in multiple myeloma
Exercise craving potentiates excitatory inputs to ventral tegmental area dopaminergic neurons
International audiencePhysical exercise, which can be addictogenic on its own, is considered a therapeutic alternative for drug craving. Exercise might thus share with drugs the ability to strengthen excitatory synapses onto ventral tegmental area (VTA) dopaminergic neurones, as assessed by the ratio of AMPA receptor (AMPAR)âmediated excitatory postsynaptic currents (EPSCs) to NMDA receptor (NMDAR)âmediated EPSCs. As did acute cocaine, amphetamine, or Î9âtetrahydrocannabinol (THC) pretreatments, an acute 1âh wheelârunning session increased the AMPAR/NMDAR ratio in VTA dopaminergic neurones. To dissect the respective influences of wheelârunning seeking and performance, mice went through an operant protocol wherein wheelârunning was conditioned by nose poking under fixed ratio schedules of reinforcement. Conditioned wheelârunning increased the AMPAR/NMDAR ratio to a higher extent than free wheelârunning, doing so although running performance was lower in the former paradigm than in the latter. Thus, the cueâreward association, rather than reward consumption, played a major role in this increase. The AMPAR/NMDAR ratio returned to baseline levels in mice that had extinguished the cuedârunning motivated task, but it increased after a cueâinduced reinstatement session. The amplitude of this increase correlated with the intensity of exercise craving, as assessed by individual nose poke scores. Finally, cueâinduced reinstatement of running seeking proved insensitive to acute cocaine or THC pretreatments. Our study reveals for the first time that the drive for exercise bears synaptic influences on VTA dopaminergic neurones which are reminiscent of drug actions. Whether these influences play a role in the therapeutic effects of exercise in human drug craving remains to be established