Cortical, subcortical and brain stem projections to the TS and DMS. (A) Dorsal view of the striatum showing red and green retrobead injection sites in the TS and DMS of rat #4. (B) Retrogradely labeled neurons from the TS injection site in a coronal brain section. The fluorescent signals were mostly found in the soma of neurons (right). These labeled neurons are marked as red dots and overlaid on a Nissl-stained brain section (left). V2M, medial part of the secondaryvisual cortex; V1, primary visual cortex; V2L, lateral part of the secondary visual cortex; A2, secondary auditory cortex; A1, primary auditory cortex; TeA, temporal association cortex; PRh, perirhinal cortex; Ent, entorhinal cortex. (C) TS-projecting neurons on coronal slices across the rostral-caudal axis. (D) Distributions of TS- and DMS-projecting neurons at 400-μm intervals in the rostral-caudal axis (TS-projecting neurons, n = 6 hemispheres; DMS-projecting neurons, n = 4 hemispheres). (E–G) Proportions of TS-projecting neurons in the cortical, subcortical, and brain stem regions (n = 6 hemispheres). TS-projecting neurons were mainly found in the midbrain, at ventral to the cerebral aqueduct, and dorsal to the medial longitudinal fasciculus, which may be the parvicellular part of the oculomotor nucleus (putative 3PC). PBP, parabrachial pigmented nucleus of the VTA; MT, medial terminal nucleus of the accessory optic tract. ***p < 0.001.