Amygdaloid metabotropic glutamate receptor subtype 7 is involved in the acquisition of conditioned fear

The metabotropic glutamate receptor subtype 7 (mGluR7) is presynaptically located and modulates transmitter release. An earlier study from our group demonstrated that systemic administration of NN'-dibenzyhydryl-ethane-1,2-diamine dihydrochloride (AMN082), a selective allosteric mGIuR7 agonist, attenuates the acquisition of conditioned fear measured by fear-potentiated startle. Aim of this study was to explore whether this effect is mediated by the basolateral amygdala, a crucial brain structure for acquisition of conditioned fear. Therefore, AMN082 was locally injected into the basolateral amygdala of rats and the effects of these injections on the acquisition of conditioned fear was measured. Our data clearly show that intra-amygdala injection of AMN082 impairs fear acquisition. This finding demonstrates that amygdaloid mGluR7 controls the learning of conditioned fear. NeuroReport 19:1147-1150 (C) 2008 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.