Location, architecture, and retinotopy of the anteromedial lateral suprasylvian visual area (AMLS) of the ferret (Mustela putorius).

The present paper describes the results of architectural and electrophysiological mapping observations of the medial bank of the suprasylvian sulcus of the ferret immediately caudal to somatosensory regions. The aim was to determine if the ferret possessed a homologous cortical area to the anteromedial lateral suprasylvian visual area (AMLS) of the domestic cat. We studied the architectural features and visuotopic organization of a region that we now consider to be a homologue to the cat AMLS. This area showed a distinct architecture and retinotopic organization. The retinotopic map was complex in nature with a bias towards representation of the lower visual field. These features indicate that the region described here as AMLS in the ferret is indeed a direct homologue of the previously described cat AMLS and forms part of a hierarchy of cortical areas processing motion in the ferret visual cortex. With the results of the present study and those of earlier studies a total of twelve cortical visual areas have been determined presently for the ferret, all of which appear to have direct homologues with visual cortical areas in the cat (which has a total of eighteen areas).