Immunohistochemical distribution of calretinin and calbindin (D-28k) in the brain of the cladistian Polypterus senegalus

Patricia Graña, Mónica Folgueira, Gema Huesa, Ramón Anadón, Julián Yáñez

    Research output: Contribution to journalArticleResearchpeer-review

    15 Citations (Scopus)


    Polypteriform fishes are believed to be basal to other living ray-finned bony fishes, and they may be useful for providing information of the neural organization that existed in the brain of the earliest ray-finned fishes. The calcium-binding proteins calretinin (CR) and calbindin-D28k (CB) have been widely used to characterize neuronal populations in vertebrate brains. Here, the distribution of the immunoreactivity against CR and CB was investigated in the olfactory organ and brain of Polypterus senegalus and compared to the distribution of these molecules in other ray-finned fishes. In general, CB-immunoreactive (ir) neurons were less abundant than CR-ir cells. CR immunohistochemistry revealed segregation of CR-ir olfactory receptor neurons in the olfactory mucosa and their bulbar projections. Our results confirmed important differences between pallial regions in terms of CR immunoreactivity of cell populations and afferent fibers. In the habenula, these calcium-binding proteins revealed right-left asymmetry of habenular subpopulations and segregation of their interpeduncular projections. CR immunohistochemistry distinguished among some thalamic, pretectal, and posterior tubercle-derived populations. Abundant CR-ir populations were observed in the midbrain, including the tectum. CR immunoreactivity was also useful for characterizing a putative secondary gustatory/visceral nucleus in the isthmus, and for distinguishing territories in the primary viscerosensory column and octavolateral region. Comparison of the data obtained within a segmental neuromeric context indicates that some CB-ir and CR-ir populations in polypteriform fishes are shared with other ray-finned fishes, but other positive structures appear to have evolved following the separation between polypterids and other ray-finned fishes. © 2013 Wiley Periodicals, Inc.
    Original languageEnglish
    Pages (from-to)2454-2485
    JournalJournal of Comparative Neurology
    Issue number11
    Publication statusPublished - 1 Aug 2013


    • Bichir
    • Bony fishes
    • Calcium-binding proteins
    • Immunohistochemistry


    Dive into the research topics of 'Immunohistochemical distribution of calretinin and calbindin (D-28k) in the brain of the cladistian Polypterus senegalus'. Together they form a unique fingerprint.

    Cite this