Research Report Thalamic afferent and efferent connectivity to cerebral cortical areas with direct projections to identified subgroups of trigeminal premotoneurons in the rat Tahsinul Haque a , Shinya Yamamoto a,b , Yuji Masuda c , Takafumi Kato a , Fumihiko Sato a , Katsuro Uchino a , Ayaka Oka a , Masahiro Nakamura a , Rieko Takeda a , Takahiro Ono d , Mikihiko Kogo b , Atsushi Yoshida a, ⁎ a Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan b Department of Oral and Maxillofacial Surgery, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan c Division of Oral Maxillofacial Biology, Institute for Oral Science, Matsumoto Dental University, Nagano 399-0781, Japan d Department of Prosthodontics and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan ARTICLE INFO ABSTRACT Article history: Accepted 12 May 2010 Available online 19 May 2010 The roles of supramedullary brain mechanisms involved in the control of jaw movements are not fully understood. To address this issue, a series of retrograde (Fluorogold, FG) and anterograde (biotinylated dextran amine, BDA) tract-tracing studies were done in rats. At first, we identified projection patterns from defined sensorimotor cortical areas to subgroups of trigeminal premotoneurons that are located in defined brainstem areas. Focal injections of FG into these brainstem areas revealed that the rostralmost part of lateral agranular cortex (rmost-Agl), the rostralmost part of medial agranular cortex (rmost-Agm), and the rostralmost Keywords: Cortex Corticofugal BRAIN RESEARCH 1346 (2010) 69 – 82 ⁎ Corresponding author. Department of Oral Anatomy and Neurobiology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan. Fax: +81 6 6879 2880. E-mail address: yoshida@dent.osaka-u.ac.jp (A. Yoshida). Abbreviations: ABC, avidin-biotin-peroxidase complex; ACg, anterior cingulate cortex; AD, anterodorsal nucleus of the thalamus; Agl, lateral agranular cortex; Agm, medial agranular cortex; AM, anteromedial nucleus of the thalamus; AV, anteroventral nucleus of the thalamus; BDA, biotinylated dextranamine; cc, corpus callosum; CL, central lateral nucleus of the thalamus; Cl, claustrum; CM, central medial nucleus of the thalamus; CMaAd, deep part of the cortical masticatory area; d-Vjuxt, dorsal part of the juxtatrigeminal region; FG, Fluorogold; fr, fasciculus retroflexus; gcc, genu of the corpus callosum; IMD, intermediodorsal nucleus of the thalamus; Ins, insular cortex; JC, jaw-closing; JCc, JC component of the Vmo; JMCA, jaw movement-related cerebral cortical area; JO, jaw-opening; JOc, JO component of the Vmo; LD, laterodorsal nucleus of the thalamus; LG, lateral geniculate nucleus of the thalamus; LP, lateral posterior nucleus of the thalamus; MD, mediodaorsal nucleus of the thalamus; MIoro, primary orofacial motor area; ml, medial lemniscus; mt, mammilothalamic tract; NGS, normal goat serum; Or, orbital cortex; PB, phosphate buffer; PBS, phosphate-buffered saline; PC, paracentral nucleus of the thalamus; Pf, parafascicular nucleus of the thalamus; Po, posterior nucleus of the thalamus; PrL, prelimbic cortex; PV, paraventricular nucleus of the thalamus; Re, reuniens nucleus of the thalamus; Rh, rhomboid nucleus of the thalamus; RmJO, reticular formation medial to the JO component of the Vmo; rmost-Agl, rostralmost part of the Agl; rmost-Agm, rostralmost part of the Agm; rmost-S1, rostralmost part of the S1; Rt, reticular nucleus of the thalamus; S1, primary somatosensory cortex; Sm, submedial nucleus of the thalamus; SMAoro, supplementary orofacial motor area; Sol, nucleus of the solitary tract; VA, ventral anterior nucleus of the thalamus; Vidm, dorsomedial subnucleus of the trigeminal interpolar nucleus; Vint, intertrigeminal region; Vivl, ventrolateral subnucleus of the trigeminal interpolar nucleus; VL, ventral lateral nucleus of the thalamus; VM, ventromedial nucleus of the thalamus; Vmes, trigeminal mesencephalic nucleus; Vmo, trigeminal motor nucleus; Vp, trigeminal principal nucleus; VPL, ventral posterolateral nucleus of the thalamus; VPM, ventral posteromedial nucleus of the thalamus; VPpc, parvicellular ventral posterior nucleus of the thalamus; Vsup, supratrigeminal nucleus; Vtr, trigeminal spinal tract; ZI, zona incerta of the thalamus 0006-8993/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.brainres.2010.05.034 available at www.sciencedirect.com www.elsevier.com/locate/brainres