Involvement of Adult-born and Preexisting Olfactory Bulb and Dentate Gyrus Neurons in Single-trial Olfactory Memory Acquisition and Retrieval.

The production of new neurons and their incorporation into preexisting neuronal circuits occur throughout adulthood in the olfactory bulb and the hippocampal dentate gyrus of the mammalian brain. To determine whether the adult-born neurons are engaged in the acquisition and retrieval of olfactory associative memory, we developed and validated a single-trial olfactory fear conditioning protocol in mice which allows to detect activation of newborn neurons during a specific episode of memory acquisition. Using c-Fos mapping of neuronal activity, we then examined the activation of new and preexisting neurons during training and testing sessions.

Slowly Reducible Genetically Encoded Green Fluorescent Indicator for In Vivo and Ex Vivo Visualization of Hydrogen Peroxide.

Hydrogen peroxide (HO) plays an important role in modulating cell signaling and homeostasis in live organisms. The HyPer family of genetically encoded indicators allows the visualization of HO dynamics in live cells within a limited field of view. The visualization of HO within a whole organism with a single cell resolution would benefit from a slowly reducible fluorescent indicator that integrates the HO concentration over desired time scales.

Suppressed neurogenesis without cognitive deficits: effects of fast neutron irradiation in mice.

This study assessed the effects of combined low-dose neutron and γ-ray irradiation on hippocampal neurogenesis and hippocampal-dependent memory. Neural progenitor cell division and survival were evaluated in brain sections and whole hippocampal preparations following head irradiation at a dose of 0.34 Gy for neutron radiation and 0.

Radiation Induces Distinct Changes in Defined Subpopulations of Neural Stem and Progenitor Cells in the Adult Hippocampus.

While irradiation can effectively treat brain tumors, this therapy also causes cognitive impairments, some of which may stem from the disruption of hippocampal neurogenesis. To study how radiation affects neurogenesis, we combine phenotyping of subpopulations of hippocampal neural stem and progenitor cells with double- and triple S-phase labeling paradigms. Using this approach, we reveal new features of division, survival, and differentiation of neural stem and progenitor cells after exposure to gamma radiation.

Spatial geometry of stem cell proliferation in the adult hippocampus.

The modes of stem cell divisions (e.g., symmetric vs.