Med. Weter. 69 (2), 112-115, 2013
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| Jaworska-Adamu J., Szalak R., Krawczyk A., Rycerz K. |
| Immunohistochemical analysis of parvalbumin in the frontal cortex of Chinchilla lanigera |
| Parvalbumin (PV), intracellular slow buffer regulates concentration of calcium ions protecting neurons from its excitotoxicity. This protein was described in inhibitory neurons of neocortex in many species of mammals, but its functions are not fully understood. In view of the absence of research on PV in the frontal cortex layers of chinchillas, we decided to trace the distribution of PV-immunoreactive neurons, demonstrate their intracellular locaition and describe their morphology. The aim of the study was also to compare the immunoreactivity of this protein in chinchllas and other species of mammals. Samples of the frontal cortex from 5 sexually mature chinchilla lanigera males was taken for the examination and after appropriate fixation, peroxidase-antiperoxidase immunohistochemical reaction was carried out with a monoclonal antibody against parvalbumin. In molecular layer (I) no nerve cells with PV expression of the examined protein were found but intensive PV immunoreactivity was observed in scattered neurons of the following layers: external granular (II), external pyramidal (III), internal granular (IV), internal pyramidal (V) and heteromorphic cells (VI). Within layer II and IV few, small, stellate, oval and fusiform cells were detected with intensive immunoreactivity in cell bodies and initial processes. Layers III and IV showed neurons of various sizes and shapes. Only layer V was characterized by the presence of the examined protein expression in pyramidal cells. Whereas, layer VI contained slightly more heteromorphic neurons with intensive PV immunoreactivity. In all examined layers of chinchilla's frontal cortex protein localized nuclearly and cytoplasmicly in cells. The obtained results of our own research concerning PV expression in different layers of frontal cortex show similarities and slight differences between species. Nerve cells containing PV should be considered as a specific subpopulation of GABAergic interneurons, which modulate the excitability of other neurons affecting the stability of neuronal nets in frontal cortex of chinchilla langera. |
| Key words: chinchilla, frontal cortex, parvalbumin |