title: Glutamatergic thalamopallial projections in the pigeon identified by retrograde labeling and expression of vGluT2 mRNA.
abstract: A neocortical hypothesis as to homology of certain nuclear components of the avian brain proposes that the entopallium and field L2 are homologous to layer 4 of mammalian extrastriate and auditory neocortex, respectively. However, the hypothesis lacks support from the neurochemistry of thalamopallial projections. We investigated whether these projections are glutamatergic by injecting cholera toxin B into either the entopallium or field L2 in combination with in situ hybridization. Retrogradely labeled neurons in nucleus rotundus and nucleus ovoidalis were found to express vesicular glutamate transporter 2 mRNA, showing that the thalamopallial projections are glutamatergic. The results are consistent with the neocortical hypothesis.
authors.affiliation: Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan. Electronic address: atozi@gifu-u.ac.jp.
authors.forename: Yasuro
authors.initials: Y
authors.lastname: Atoji
authors.affiliation: Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan; Department of Anatomy and Histology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
authors.forename: Mohammad Rabiul
authors.initials: MR
authors.lastname: Karim
mesh_terms: D000818:Animals; D002772:Cholera Toxin / Q000378:metabolism; D010856:Columbidae; D005917:Globus Pallidus / Q000166:cytology*; D018698:Glutamic Acid / Q000378:metabolism*; D019579:Neocortex / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D018091:Receptors, AMPA / Q000235:genetics / Q000378:metabolism; D013788:Thalamus / Q000166:cytology*; D050599:Vesicular Glutamate Transport Protein 2 / Q000235:genetics* / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D018091:Receptors, AMPA; D050599:Vesicular Glutamate Transport Protein 2; D018698:Glutamic Acid; D002772:Cholera Toxin
keywords: Bird; Entopallium; Field L2; Homology; Layer 4