Calleja's Islands

Insulae callejae

Concentrated accumulations of acetylcholine-producing grain cells which, in primates, are located ventrally to the nucleus accumbens, i.e., in the ventral striatum of the basal forebrain.

The cilleja cells have the ability to produce relatively large amounts of nitric oxide (vasodilator effect) and are thought to be able to control blood flow from circulus Willisi to the basal forebrain. Furthermore, they are of importance for the "brain reward system" and the emergence of drug addiction.