Impact of dihydropyrimidinase-related protein 2 in memory formation on rats and its possible role in neuronal back remodeling

The article concerns the problem of molecular mechanisms of memory formation. In this study the effects of polyclonal antibodies to serotonin-modulating anticonsolidation protein (SMAP) complex and its component dihydropyrimidinase-related protein 2 (DRP2) have been analyzed. Intra-cerebral administration of polyclonal anti-SMAP antibody significantly enhanced elaboration and strengthened memory formation in two complex behavioral conditioned models. At the same time, intra-cerebral administration of anti-SMAP antibody resulted in an increase of the content of nerve growth factor (NGF) in the water-soluble fraction of the hippocampus while intra-cerebral administration of anti-DRP2 antibody caused a decrease in the content of β-III tubulin (a marker of differentiated neurons) in the hippocampus and in the left parietal cortex of untrained rats. The obtained results indicate that DRP2 might participate in regulation of the processes of back remodeling of mature nerve cells of adult organisms, occurring during training of rats in the behavioral paradigm used in this study under the effects of anti-SMAP and anti-DRP2 antibodies. Conclusion is made that back remodeling (dedifferentiation) of mature nerve cells, apparently, is engaged in memory formation.

Structure of neuro-endocrine and neuro-epithelial interactions in human foetal pancreas

In the pancreas of many mammals including humans, endocrine islet cells can be integrated with the nervous system components into neuro-insular complexes. The mechanism of the formation of such complexes is not clearly understood. The present study evaluated the interactions between the nervous system components, epithelial cells and endocrine cells in the human pancreas. Foetal pancreas, gestational age 19-23 weeks (13 cases) and 30-34 weeks (7 cases), were studied using double immunohistochemical labeling with neural markers (S100 protein and beta III tubulin), epithelial marker (cytokeratin 19 (CK19)) and antibodies to insulin and glucagon. We first analyse the structure of neuro-insular complexes using confocal microscopy and provide immunohistochemical evidences of the presence of endocrine cells within the ganglia or inside the nerve bundles. We showed that the nervous system components contact with the epithelial cells located in ducts or in clusters outside the ductal epithelium and form complexes with separate epithelial cells. We observed CK19-positive cells inside the ganglia and nerve bundles which were located separately or were integrated with the islets. Therefore, we conclude that neuro-insular complexes may forms as a result of integration between epithelial cells and nervous system components at the initial stages of islets formation.