A cortical substrate for memory guided-orienting

Jeffrey C. Erlich, Max Bialek and Carlos D. Brody

Neuron, Volume 72, Issue 2, 330-343

 

Have you ever heard of the rat frontal eye fields? 

We hadn’t either.  But a literature search revealed a small but fascinating set of papers that suggested that the rat might have a frontal cortical structure homologous to the primate frontal eye field (FEF)!  Why is this exciting?  Because the FEF is a key element in the circuit for spatial attention & memory and for the planning/preparation and execution of orienting movements.  We want to understand the neural mechanisms of these behavioral phenomena using the rat as an animal model, so the “rat FEF” might be a good place to start. 

We set out to test whether this structure, which we call the frontal orienting field (FOF), was involved in memory-guided orienting.  In this task subjects are presented with an auditory cue that indicates which way they should orient to obtain a reward. However, the subjects are only allowed to respond after a delay. The task thus separates the stimulus from the response in the tradition of classic memory-guided tasks.  In primates the FEF is essential for successful performance on these types of tasks.  Using pharmacology and electrophysiology we demonstrated that the rat FOF is required for memory-guided orienting and that neural activity in the FOF predicts the upcoming orienting motion of the rat!


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Orienting fields have been identified in humans, monkeys, cats, owls, and now rats!

Jeffrey C Erlich