NMDA receptor ablation on parvalbumin-positive interneurons impairs hippocampal synchrony, spatial representations, and working memory

Activity of parvalbumin-positive hippocampal interneurons is critical for network synchronization but the receptors involved therein have remained largely unknown. Here we report network and behavioral deficits in mice with selective ablation of NMDA receptors in parvalbumin-positive interneurons (NR1(PVCre-/-)). Recordings of local field potentials and unitary neuronal activity in the hippocampal CA1 area revealed altered theta oscillations (5-10 Hz) in freely behaving NR1(PVCre-/-) mice. Moreover, in contrast to controls, in NR1(PVCre-/-) mice the remaining theta rhythm was abolished by the administration of atropine. Gamma oscillations (35-85 Hz) were increased and less modulated by the concurrent theta rhythm in the mutant. Positional firing of pyramidal cells in NR1(PVCre-/-) mice was less spatially and temporally precise. Finally, NR1(PVCre-/-) mice exhibited impaired spatial working as well as spatial short- and long-term recognition memory but showed no deficits in open field exploratory activity and spatial reference learning.     

Several indices of the peripheral immune system in clean up team workers and patients who survived acute radiation disease 5 years after effects of the radiation accident factors]

A group of liquidators and patients survived acute radiation sickness (ARS) was studied five years after the effect of radiation factors resulted from the Chernobyl A.P.S. disaster. Studied were the number of T-lymphocytes (SD2+, SD3+, SD5+), subpopulations SD16+ and SD25+, the content of SD16+ and SD25+ lymphocytes and B-cells, as well as the levels of serum IgM, A, G; determined was the concentration of serum alpha 1-thymosin. A decrease was noted in the number of T-cells of the examined patients, with respect to all markers studied: the number of SD4+ cells was found decreased in patients with ARS sequelae and normal in liquidators. The decrease in serum alpha 1-thymosin was a function of dose. Dynamics of changes in the T-cells of the examinees may reflect the new trends in the radiation response of T-lymphocytes which were not directly related to initial damages to the latter. The injury to the stroma of the thymus and especially to its epithelial cells may be the basis for later postirradiation damages to the immune system. The decrease in the concentration of alpha 1-thymosin in the blood serum of the examinee is the manifestation of the thymus hypofunction. In liquidators and patients with the ARS sequelae the number of SD25+ cells increased markedly indicating the existence of the source of endogenous cell activation. The content of B-lymphocytes in all studied groups of patients was reduced which may serve as a criterion of chronic stress.     

Novel miRNAs as Potential Regulators of PD-1/PD-L1 Immune Checkpoint,and Prognostic Value of MIR9-1 and MIR124-2 Methylation in Ovarian Cancer

Molecular Biology - Ovarian cancer (OC) is mostly detected at late stages weighed down with metastasis, and the five-year survival rate of patients is only 30%, which dictates the necessity to...     

MIR: Family of repeats common to vertebrate genomes

We studied the occurrence of mammalian interspersed repeats (MIRs) in DNA and RNA of vertebrates, invertebrates, and bacteria using the data from GenBank. A special algorithm based on a weight position matrix with optimal alignment using dynamic programming was developed to search for the traces of MIR dissemination. This allowed us to search for highly divergent MIRs carrying deletions and insertions. MIRs were detected in genomes of various fishes, includingLatimeria. This suggests that the origin of MIRs dates back more than 400 million years. The method to search for similarity between highly divergent sequences may be used to find the genome fragments from various ancient repeat families and from various gene families.