(1) the posterior tegmental decussation [TA] (dorsal tegmental decussation [TA], fountain decussation, Meynert decussation) is formed by the crossing of the left and right tectospinal and tectobulbar tracts; (2) the anterior tegmental decussation [TA] (ventral tegmental decussation [TA], Forel decussation) is formed by the crossing of the left and right rubrospinal and rubrobulbar tracts; both decussations are located in the mesencephalon. SYN: decussationes tegmentales [TA].