Bilateral projections from the visual cortex to the striatum in the cat

Area of Science:

• Neuroscience
• Visual System Anatomy

Background:

• The striatum receives input from various cortical areas, but direct visual cortex projections remain incompletely understood.
• Previous studies have suggested potential visual-cortical connections to the striatum, necessitating further investigation.

Purpose of the Study:

• To map direct projections from specific visual cortical areas to the striatum in adult cats.
• To characterize the laterality and topographical organization of these visual-striatal pathways.

Main Methods:

• Autoradiographic technique was employed to trace neuronal pathways.
• Injections were made into visual areas 17, 18, 19, and the lateral suprasylvian visual area (LS) in 12 adult cats.

Main Results:

• Direct projections to the striatum were identified exclusively from visual areas 19 and LS.
• Both ipsilateral and contralateral projections to the caudate nucleus and putamen were observed from areas 19 and LS.
• Contralateral projections from area 19 did not extend to the putamen, and all contralateral projections were less extensive than ipsilateral ones.
• Cluster-like arrangements of silver grains, indicative of projection patterns, were noted, particularly ipsilaterally in the caudate nucleus and following LS injections.

Conclusions:

• The findings indicate that visual areas 19 and LS directly project to the striatum in cats.
• The data suggest a non-strictly topographical organization of striatal projections originating from the cat visual cortex.
• These projections exhibit both ipsilateral and contralateral components, with variations in extent and target specificity.