Neostriatum and functions of prefrontal cortex.

A review of recent anatomical evidence shows that every neocortical area and many nuclei from the dorsal thalamus project to restricted neostriatal regions. The neurobehavioral literature offers many examples of the same results obtained with lesions, stimulations or recordings in a neocortical area and the associated neostriatal region. This evidence is abundant in the case of the prefrontal cortex and rostra1 neostriatum, but it is available also for other corticoneostriatal pairs. It seems possible to conclude that the function of a neostriatal region is determined by its cortical and possibly by its thalamic input. However, the possibility that the behavioral effects of lesions and stimulation of neostriatum were in fact produced by involving the fibers passing to and from the overlying cortex has not been convincingly excluded. An attempt was made to develop a simple concept about the relation between the prefrontal cortex and the region of neostriatum associated with it. A serial paradigm, suggesting that prefrontal cortex in adult monkeys and cats acts via neostriatum when mediating performance in certain behavioral tasks, seems to account for most of the available data.