UST Biology’s Jadin Jackson and colleagues recently published a study in the Journal of Neuroscience. Below is a general audience description. The full article is available here.
Learning to associate rewarding experiences with the location at which they occurred is a fundamental adaptation for survival, that allows us to return to a food source or other primary reward in order to get more of something valuable. Using rats, we studied the simultaneous activity in two important brain regions involved in learning these reward-place associations and planning actions that will lead to reward: the hippocampus, involved in place and episode learning; and the ventral striatum which uses location and reward-related information for the planning of actions. We found that neurons in the hippocampus most reliably represented the location of an animal when the animal was able to predict that a reward would be available, and that ventral striatal neurons included more spatial information in their activity during this same period. Additionally, the activity of neurons in the hippocampus much more precisely locked to the time it would take the animal to reach a reward, fitting with the involvement of the hippocampus in human episodic memory. This study clarifies the information being processed by these two important brain regions and how the presence of reward-predictive cues in an environment will bias that information.
Lansink C., Jackson J.C., Lankelma J., Ito R. , Robbins T.W. , Everitt B., Pennartz C.M.A. (2012) Reward cues in space: commonalities and differences in neural coding by hippocampal and ventral striatal ensembles. Journal of Neuroscience 32:12444-12459