Visual cortex DUBLETT

Primary visual cortex

V1, Area 17, BA 17, Homonymous hemianopsia

Area 17 is the reception area for visual impressions in the cerebrum cortex. The area, which comprises a comparatively large bark field on the inside of the hemisphere adjacent to the deep tractive cortex furrow of the occipital lobe (sulcus calcarinus/fissura calcarina), is usually referred to as the primary visual cortex/primary visual cortex/area striata/V1; V = visual; i.e. has to do with vision.

The bark in area 17 looks very special.
The microcolumns here consist of twice as many successive stacked neurons, approx. 200 pcs., which is otherwise the rule in the modern type of cerebrum cortex. This type of highly cell-rich visual cortex occurs only in humans and their closest relatives among the great apes (primates).

The visual cortex is divided into two gray layers, one outer and one inner, separated by a thin white streak (1/2 mm thick and clearly visible to the naked eye), Gennaris streak. The streak is due to the fact that the primary visual cortex in its lamina IV contains a layer of densely packed myelinated nerve fibers. The primary visual cortex is therefore often called Area striata.

An injury that is limited to the primary visual cortex on one hemisphere of the brain, here the left, leads to blindness within the opposite half of the visual field, here the right, in both eyes: right-sided homonymous hemianopsia