[The function of the precortical arteries]

In anesthetized adult rabbits, the responses of pial and precortical arteries to retinal photostimulation and the application of 0.5% strychnine solution to the brain surface were studied, as well as the distribution of cholinergic and adrenergic nerve fibres in these microvessels. The precortical arteries showed the highest degree of dilatation and frequency of responses. Dense innervation was mostly in evidence in the precortical arteries. Upon atropin application, the response suppression was also more obvious in the precortical arteries. The data suggest that the precortical arteries play an important role in regulation of the adequate blood supply to the brain tissue.