Anatomy of the caudal cerebral artery on the surface of opossum brain (Didelphis albiventris)

ABSTRACT

The anatomy of the caudal cerebral artery of the opossum Didelphis albiventris was examined in 30 brains with the cervical segment of the spinal cord attached. For examination, the arterial system of the brains was perfused with colored latex and fixed in 20 per cent formalin. The caudal cerebral artery originated from the caudal communicating artery at the level of the cerebral peduncles, then went to the transversal fissure from where it sent three main branches to the mesencephalic tectum on the dorsal surface of the thalamus, the stria medullaris, the pineal body and the tentorial and medial surfaces of the cerebral hemisphere. The caudal cerebral artery was present in all specimens and gave rise to two main collateral branches - the tentorial hemispheric branch and the rostral tectal artery. The tentorial hemispheric branch originated from the caudal communicating artery on the right and left sides in 83.3 per cent and 80 per cent of the cases respectively, from the caudal communicating artery on both sides in 10 per cent of the samples and from the middle-rostral cerebral trunk in 6.7 per cent of the preparations ont the right side and in 10 per cent on the left side. The rostral tectal artery on the right was single in 96.7 per cent of the cases and double in 3.3 per cent; on the left side, the artery was single in all specimens. After giving rise to two collateral rami, the caudal cerebral artery crossed the dorsal surface of the thalamus, giving off small branches to the pineal gland and the stria medullaris. At the level of the rostral tubercle of the thalamus, the artery ran towards the medial surface of the cerebral hemisphere. The terminal branch anastomosed with the tentorial hemispheric ramus to form the caudal inter-hemispheric artery in 93.3 per cent and 86.7 per cent of the cases on the right and left sides, respectively.