The role of the PVT in motivated behavior Wesley Dixon, Anmolpreet Kandola, Yingjie Zhu1, Xiaoke Chen1

1Department of Biology, Stanford University

Previous studies have shown that the paraventricular nucleus of the thalamus (PVT) plays an important role in the neural circuitry controlling opiate withdrawal symptoms. Little is known, however, about the overall function of the PVT in regards to more general motivation-dependent behaviors and learning. Here, we examine the role that the PVT plays in motivated behaviors and Pavlovian learning by training mice in simple, thirst-motivated Go-No-Go behavior tasks. More specifically, mice are trained to lick at one odor cue to receive water, and not to lick at a different odor cue to avoid punishment. We infuse muscimol, a potent GABA-receptor agonist, into the PVT to inhibit neural activity in the region, allowing us to examine the role that the PVT plays in the behavior of the mice.

Results

Future Directions

Conclusions

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Figure 1: The Go-No-Go behavioral paradigm used to train mice to discriminate between two odors.

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Methods

1.  We have shown that the PVT is required for motivated behavior and for the expression of Pavlovian learning.

2.  Silencing PVT activity decreases the frequency and accuracy of reward-seeking licking behavior in our behavioral paradigm.

3.  Silencing PVT activity does not dramatically affect thirst or motor function.

4.  Based on the data, there are many possible roles of the PVT in motivated behavior, inlcuding:

a.  Formation of an association between cue and removal of an aversive state.

b.  Regulation of the salience of the cue. c.  Memory recall or memory induction.

1.  Silence PVT activity before training to test if the PVT plays a role in memory induction or memory recall.

2.  Analyze the licking behavior over time of mice in the behavioral paradigm to test whether silencing PVT activity weakens the association between a cue and a removal of an aversive state.

3.  Use sugar water in the behavioral paradigm to examine how PVT plays a role in reward seeking pathways as opposed to negative reinforcement pathways.

Acknowledgements

Thank you to the VPUE program for making this lab time possible, and to all of the members of the Chen lab for helping

me, guiding me, and encouraging me!

Introduction

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Figure 2: Efficacy of training paradigm for Go-No-Go learning

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Figure 3: Validation of infusion localization in the brain using DiI.

Learning Plot (no manipulation)

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Time (within trial)

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Figure 4: Infusion of muscimol (a GABA-receptor agonist) significantly hinders Go-

No-Go licking behavior.

Time (within trial)

Learning Plot (300 nL muscimol à PVT)

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Figure 5: After infusion, mice are replaced in the home with free access to water. Muscimol infusion did not

reduce thirst or impair motor function.

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p = 0.140

p = 0.428

Odor Delivery