Calretinin expression in specific neuronal systems in the brain of an advanced teleost, the grey mullet (Chelon labrosus)

Abstract

The distribution of calretinin (CR) in the brain of an "advanced" teleost, the grey mullet, was studied by using immunoblotting and immunocytochemical techniques. In immunoblots of protein extracts of rat and mullet brains, the CR antibody stained a single band of about 29 kDa. CR immunoreactivity was observed in specific neuronal populations of all brain regions. The primary olfactory system, the optic nerve fibers, and some sensory fibers of other cranial nerves exhibited strong CR immunoreactivity. In the forebrain, the CR-immunoreactive (CR-ir) populations were scarce in the telencephalon and hypophysiotrofic hypothalamus, but numerous in many specialized nuclei of the diencephalon (preglomerulosus complex, nucleus glomerulosus, anterior glomerular nucleus, nucleus diffusus) and pretectum (parvocellular and magnocellular superficial pretectal nuclei, central pretectal nucleus), which are related to sensory systems. The two main forebrain bundles, medial and lateral, contained numerous CR-ir fibers. The midbrain sensory centers (optic tectum and torus semicircularis) exhibited numerous CR-ir cells and fibers. Likewise, the secondary gustatory nucleus of the isthmus is one of the nuclei exhibiting more intense CR immunoreactivity. Characteristically, the efferent cerebellar system (eurydendroid cells and brachium conjunctivum) and some afferent cerebellar fibers were CR-ir. In the medulla oblongata, a number of reticular cells, the inferior olive, and the magnocellular octaval nucleus exhibited CR immunoreactivity. CR-ir motoneurons were also observed in the spinal cord and in the oculomotor nucleus. Together with results obtained in other vertebrates, present results suggest that neural systems using calretinin to maintain intracellular calcium concentration have been rather well conserved during vertebrate evolution.

Short-term exposure to L-type calcium channel blocker, verapamil, alters the expression pattern of calcium-binding proteins in the brain of goldfish, Carassius auratus

“…Therefore, in the present study, an attempt was made to understand distribution patterns for the first time in the brain of C. auratus. The immunohistochemical localization patterns from our studies are similar to those found in other teleosts (Castro et al, 2006a(Castro et al, , 2006bDíaz-Regueira and Anadón, 2000;Puschina and Varaksin, 2011), with some variations. Since CR and PV are known calcium buffers that regulate intracellular Ca 2+ , the expression of these proteins could be altered by the action of xenobiotics like VRP, which is a potent calcium channel blocker.…”

“…For identifying various nuclei of the goldfish brain, various articles illustrating fish brain cytoarchitecture were referred (Braford and Northcutt, 1983;Castro et al, 2006aCastro et al, , 2006bDíaz-Regueira and Anadón, 2000;Jadhao and Malz, 2007;Peter and Gill, 1975;Rupp et al, 1996).…”

Phylogeny of nucleus medianus of the posterior tubercle in rayfinned fishes

“…In many cases, the mounted sections were counterstained with 1% neutral red before being coverslipped. Both primary antisera have been well characterized in several teleosts (Díaz-Regueira & Anadón 2000;Rink and Wullimann 2001;Anadón et al 2002;Castro et al 2003;Northcutt 2006), and no tissues reacted when these antisera were omitted from the protocol as a control.…”

Distribution of calretinin during development of the olfactory system in the brown trout, Salmo trutta fario: Comparison with other immunohistochemical markers

“…Among calcium-binding proteins, CR has proved to be a valuable marker of some developing neuronal populations in the olfactory system of mammals Pochet, 1994, 1995;Wouterlood and Hä rtig, 1995;Malz et al, 2000Alonso et al, 2001;Briñ ó n et al, 2001;Kakuta et al, 2001). CR-ir neurons have been reported in the olfactory organ and/or the olfactory bulbs of a few developing (Porteros et al, 1997) or adult teleosts (Porteros et al, 1997;Díaz-Regueira and Anadó n, 2000;Castro et al, 2006), as well as in the adult river lamprey (Pombal et al, 2002).…”