N-methyl-d-aspartate receptors in the ventral tegmental area mediate the excitatory influence of Pavlovian stimuli on instrumental performance

• Autores: Susanne Sommer, Wolfgang Hauber
• Localización: Brain Structure and Function, ISSN 1863-2653, ISSN-e 1863-2661, Vol. 221, Nº. 9, 2016, págs. 4399-4409
• Idioma: inglés
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• Resumen

  • Pavlovian stimuli predictive of food can markedly amplify instrumental responding for food. This effect is termed Pavlovian–instrumental transfer (PIT). The ventral tegmental area (VTA) plays a key role in mediating PIT, however, it is yet unknown whether N-methyl-d-aspartate (NMDA)-type glutamate receptors in the VTA are involved in PIT. Here, we examined the effects of an NMDA-receptor blockade in the VTA on PIT. Immediately prior to PIT testing, rats were subjected to intra-VTA infusions of vehicle or of the NMDA-receptor antagonist 2-amino-5-phosphonopentanoic acid (AP-5) (1, 5 µg/side). In rats that received AP-5 at the lower dose, the PIT effect was intact, i.e. presentation of the Pavlovian stimulus enhanced instrumental responding. By contrast, in rats that received AP-5 at the higher dose, the PIT effect was blocked. The data suggest that NMDA receptors in the VTA mediate the activating effects of Pavlovian stimuli on instrumental responding.