title: Distribution of calcium-binding proteins in the pigeon visual thalamic centers and related pretectal and mesencephalic nuclei. Phylogenetic and functional determinants.
abstract: Multichannel processing of environmental information constitutes a fundamental basis of functioning of sensory systems in the vertebrate brain. Two distinct parallel visual systems - the tectofugal and thalamofugal exist in all amniotes. The vertebrate central nervous system contains high concentrations of intracellular calcium-binding proteins (CaBPrs) and each of them has a restricted expression pattern in different brain regions and specific neuronal subpopulations. This study aimed at describing the patterns of distribution of parvalbumin (PV) and calbindin (CB) in the visual thalamic and mesencephalic centers of the pigeon (Columba livia). We used a combination of immunohistochemistry and double labeling immunofluorescent technique. Structures studied included the thalamic relay centers involved in the tectofugal (nucleus rotundus, Rot) and thalamofugal (nucleus geniculatus lateralis, pars dorsalis, GLd) visual pathways as well as pretectal, mesencephalic, isthmic and thalamic structures inducing the driver and/or modulatory action to the visual processing. We showed that neither of these proteins was unique to the Rot or GLd. The Rot contained i) numerous PV-immunoreactive (ir) neurons and a dense neuropil, and ii) a few CB-ir neurons mostly located in the anterior dorsal part and associated with a light neuropil. These latter neurons partially overlapped with the former and some of them colocalized both proteins. The distinct subnuclei of the GLd were also characterized by different patterns of distribution of CaBPrs. Some (nucleus dorsolateralis anterior, pars magnocellularis, DLAmc; pars lateralis, DLL; pars rostrolateralis, DLAlr; nucleus lateralis anterior thalami, LA) contained both CB- and PV-ir neurons in different proportions with a predominance of the former in the DLAmc and DLL. The nucleus lateralis dorsalis of nuclei optici principalis thalami only contained PV-ir neurons and a neuropil similar to the interstitial pretectal/thalamic nuclei of the tectothalamic tract, nucleus pretectalis and thalamic reticular nucleus. The overlapping distribution of PV and CB immunoreactivity was typical for the pretectal nucleus lentiformis mesencephali and the nucleus ectomamillaris as well as for the visual isthmic nuclei. The findings are discussed in the light of the contributive role of the phylogenetic and functional factors determining the circuits׳ specificity of the different CaBPr types.
authors.affiliation: Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44, Thorez Avenue, 194223 Saint-Petersburg, Russia. Electronic address: belekhova@yahoo.com.
authors.forename: Margarita G
authors.initials: MG
authors.lastname: Belekhova
authors.affiliation: Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44, Thorez Avenue, 194223 Saint-Petersburg, Russia. Electronic address: tvchudinova@gmail.com.
authors.forename: Tatiana V
authors.initials: TV
authors.lastname: Chudinova
authors.affiliation: CRICM UPMC/INSERM UMR_S975/CNRS UMR 7225, Hôpital de la Salpêtrière, 47, Bd de l׳Hôpital, 75651 Paris Cedex 13, France. Electronic address: jean-paul.rio@icm-institute.org.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Rio
authors.affiliation: CNRS UMR 7221, MNHN USM 0501, Département Régulations, Développement et Diversité Moléculaire du Muséum National d'Histoire Naturelle, 7, rue Cuvier, 75005 Paris, France. Electronic address: herve.tostivint@mnhn.fr.
authors.forename: Hérve
authors.initials: H
authors.lastname: Tostivint
authors.affiliation: Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44, Thorez Avenue, 194223 Saint-Petersburg, Russia; Department of Medicine, The State University of Saint-Petersburg, 7-9, Universitetskaya nab., 199034 St. Petersburg, Russia. Electronic address: npves@yahoo.com.
authors.forename: Nikolai P
authors.initials: NP
authors.lastname: Vesselkin
authors.affiliation: Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44, Thorez Avenue, 194223 Saint-Petersburg, Russia; CNRS UMR 7221, MNHN USM 0501, Département Régulations, Développement et Diversité Moléculaire du Muséum National d'Histoire Naturelle, 7, rue Cuvier, 75005 Paris, France. Electronic address: kenig51@yahoo.com.
authors.forename: Natalia B
authors.initials: NB
authors.lastname: Kenigfest
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D001931:Brain Mapping; D064026:Calbindins / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D010856:Columbidae / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D008636:Mesencephalon / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D010320:Parvalbumins / Q000378:metabolism*; D010802:Phylogeny; D066250:Pretectal Region / Q000378:metabolism; D013787:Thalamic Nuclei / Q000378:metabolism; D013788:Thalamus / Q000378:metabolism*; D014795:Visual Pathways
chemical_list: D064026:Calbindins; D010320:Parvalbumins
keywords: Birds; Calcium-binding proteins; Immunohistochemistry; Phylogeny and functional specialization; Visual thalamic and related centers