Perirhinal input to neocortical layer 1 controls learning

Memory consolidation in the neocortex Information transfer between brain structures located in the medial-temporal lobe and the neocortex is essential for learning. However, the neuronal underpinnings of this transfer are unknown. Doronet al. found that neurons located in the deep layers of the perirhinal cortex exhibit increased firing after microstimulation upon learning (see the Perspective by Donato). Learning was associated with the emergence of a small population of neurons in layer 5 of the somatosensory cortex that increased bursting upon stimulation. This increase in bursting was accompanied by an increase in dendritic activity, and silencing the perirhinal cortex to layer 1 projection effectively disrupted learning and its physiological correlates. During learning, perirhinal inputs thus act as a gate for the enhancement of cortico-cortical inputs, which are necessary for stimulus detection and are strengthened during learning.Science , this issue p.eaaz3136 ; see also p.1410