[TA] the short, often slitlike passage that, on both the left and right side, connects the third brain ventricle (of the diencephalon) with the lateral ventricles (of the cerebral hemispheres); the passage is bounded anteriomedially by the column of fornix and posterolaterally by the anterior pole and anterior tubercle of the dorsal thalamus. SYN: foramen interventriculare [TA], Monro foramen, porta (2).
