Both humans and non-human animals have the ability to navigate and make decisions within complex environments. This ability is largely dependent upon learning and memory processes, many of which are known to depend on NMDA-sensitive receptors. When humans come to difficult decisions they often pause to deliberate over their choices. Similarly, rats pause at difficult choice points. This behavior, known as vicarious trial and error (VTE), is hippocampally dependent and entails neurophysiological representations of expectations of future outcomes in hippocampus and downstream structures. In order to determine the dependence of VTE behaviors on NMDA-sensitive receptors, we tested rats on a Multiple-T choice task with a reward-delivery reversal known to elicit VTE. Rats under the influence of NMDA-receptor antagonists (CPP) showed a significant reduction in VTE, particularly at the reward reversal, implying a role for NMDA-sensitive receptors in the generation of vicarious trial and error behaviors.
Bibliographical noteFunding Information:
This project was run as part of the 2009 NSF-sponsored REU Summer Undergraduate Research program in the Behavioral Sciences and Cognitive Sciences at the University of Minnesota. We thank the other members of the Redish lab and the other participants in the BSCS REU program for helpful discussion. Funded by NSF (0648715) and by NIH-R01-MH08318.
- CPP: 3-(2-Carboxypiperazin-4-yl)propyl-1-phosphonic acid
- DCS: D-cycloserine
- VTE: vicarious trial and error
- Vicarious trial and error