Authors:

Mitchell, A., Pekekanos, V., Premereur, E., MITCHELL, D., Mason, S., Chakraborty, S., Lee, A.

Reference:

Year of publication:

2020

CBU number:

8538

Abstract:

The frontal cortex and temporal lobes together regulate complex learning and memory capabilities. Here, we collected resting-state functional and diffusion-weighted magnetic resonance imaging data before and after male rhesus macaque monkeys received extensive training to learn novel visuospatial discriminations (reward-guided learning). We found functional connectivity changes in orbitofrontal, ventromedial prefrontal, inferotemporal, entorhinal, retrosplenial, and anterior cingulate cortices, the subicular complex and the dorsal, medial thalamus. These cortico-cortical and thalamocortical changes in functional connectivity were accompanied by related white matter structural alterations in the uncinate fasciculus, fornix, and ventral prefrontal tract – tracts that connect (sub)cortical networks and are implicated in learning and memory processes in monkeys and humans. After the well-trained monkeys received fornix transection, they were impaired in learning new visuospatial discriminations. In addition, the functional connectivity profile that was observed after the training was altered. These changes were accompanied by white matter changes in the ventral prefrontal tract although the integrity of the uncinate fasciculus remained unchanged. Our experiments highlight the importance of different communication relayed amongst cortico-cortical and thalamocortical circuitry for the ability to learn new visuospatial associations (learning-to-learn) and to make reward-guided decisions.

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Data for this project is held by an external institution. Please contact the authors to request a copy.