Arterial patterns of the rat rhinencephalon and related structures.

Course and distribution information on arteries in the rat rhinencephalon was not found in the literature. Such data are useful for designing experiments and interpreting findings, tracing nerve fibers on or to intracerebral vessels, and in considering routes for diffusion or transport of intracerebral injected agents. Adult rats were perfused with silicone rubber and many brains were cleared in glycerin. The major arteries to the olfactory bulb stem from the anterior cerebral artery. A middle cerebral arterial ramus could provide a collateral source. The septum receives supply exclusively from the anterior cerebral artery. A rostra1 lesion in the medial septum would most likely involve arteries supplying more caudal structures including hippocampal afferent and efferent fibers. No anastomoses between septal arteries or with middle or posterior cerebral arterial rami were observed. The cingulate cortex receives anterior cerebral arterial branches with the middle cerebral artery being a collateral source. The amygdala and overlying cortex receive branches of the internal carotid and middle cerebral arteries. Transverse arteries in the hippocampal fissure stem from the longitudinal hippocampal artery, a branch of the posterior cerebral artery, to nourish the hippocampus and portions of the fascia dentata. Other branches supply the remainder of the fascia dentata, entorhinal and subicular structures, and certain vessels anastomose with middle cerebral arterial rami. A transverse artery occlusion would probably result in a lesion : No intracerebral arterial anastomoses were observed. Vascular compensation may occur following occlusion of the longitudinal artery via supply from the middle cerebral artery.