[TA] a longitudinal bundle of thin, unmyelinated, and poorly myelinated fibers capping the apex of the posterior horn of the spinal gray matter, composed of posterior root fibers and short association fibers that interconnect neighboring segments of the posterior horn. SYN: posterolateral tract [TA], tractus dorsolateralis [TA], tractus posterolateralis [TA], dorsolateral tract*, fasciculus dorsolateralis, fasciculus marginalis, Lissauer bundle, Lissauer column, Lissauer fasciculus, Lissauer marginal zone, Lissauer tract, marginal fasciculus, Spitzka marginal tract, Spitzka marginal zone, Waldeyer tract, Waldeyer zonal layer.