Cognitive imparement and suppression of neurogenesis in mice after irradiation.
Bezriadnov, D.V. Mineyeva, O.A. Lazutkin, A.A. Kedrov, A.V. Barykina, N.V. Anokhin, K.V. Enikolopov, G.N.
1.NBIC-department, MIPT, Moscow, Russia; 2.NBICS center of the Kurchatov Institute, Moscow, Russia; 3.Anokhin Institute of Normal Physiology, Moscow, Russia; 4. Institute of Higher Nervous Activity and Neurophysiology of RAS, Moscow, Russia 5.Cold Spring Harbor Laboratory, Cold Spring Harbor, USA
Whole-body irradiation induces a broad response of an organism mainly affecting cell division. Loss of brain dividing cells was previously shown to be accompanied by memory impairments, which can be mainly seen at later timepoints when the brain lacks new neurons. But whereas cell loss effect is easily reproducible, behavior alterations appear to be highly protocol-dependent. Our goal was to study potential delayed cognitive deficits that follow an immediate reduction in proliferation of hippocampal neural stem and progenitor cells after irradiation. As expected, moderate doses of neutron and gamma-irradiation as well as gamma alone induced significant acute proliferation arrest and also a reduction of non-dividing cells such as quiescent neural stem cells and doublecortin neurons. Nonetheless, it had little effect on animal behavior 5 weeks after irradiation. High doses were more deleterious to dividing and non-dividing progenitors and memory deficits were found in a number of cognitive tasks.