Neonatal Peripheral Immune Challenge Activates Microglia and Inhibits Neurogenesis in the Developing Murine Hippocampus

Doxycycline increases neurogenesis and reduces microglia in the adult hippocampus

Adult hippocampal neurogenesis results in the continuous formation of new neurons and is a process of brain plasticity involved in learning and memory. Although inducible-reversible transgenic mouse models are increasingly being used to investigate adult neurogenesis, transgene control requires the administration of an activator, doxycycline (Dox), with unknown effects on adult neurogenesis. He...

Immunostimulatory CpG-DNA activates murine microglia.

Bacterial DNA containing motifs of unmethylated CpG dinucleotides (CpG-DNA) triggers innate immune cells through the pattern recognition receptor Toll-like receptor 9 (TLR-9). CpG-DNA possesses potent immunostimulatory effects on macrophages, dendritic cells, and B lymphocytes. Therefore, CpG-DNA contributes to inflammation during the course of bacterial infections. In contrast to other TLR-dep...

Murine Microglia Immunostimulatory CpG-DNA Activates

Nicotine activates immature "silent" connections in the developing hippocampus.

In the hippocampus at birth, most glutamatergic synapses are immature and functionally "silent" either because the neurotransmitter is released in insufficient amount to activate low-affinity alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptors or because the appropriate receptor system is missing or nonfunctional. Here we show that, in the newborn rat, a brief application of nicotin...

Soft-diet feeding inhibits adult neurogenesis in hippocampus of mice.

Our previous study showed that mice fed on a soft diet after weaning had reduced levels of brain-derived neurotrophic factor (BDNF) protein in the hippocampus after 3 months of age compared with mice fed on a hard diet. BDNF is one of the most effective promoters of neurogenesis in the hippocampus, and enhancement of BDNF production has been shown to enhance neural precursor cell proliferation ...