Towards an Understanding of the Dentate Gyrus Hilus.

For many years, the hilus of the dentate gyrus (DG) was a mystery because anatomical data suggested a bewildering array of cells without clear organization. Moreover, some of the anatomical information led to more questions than answers. For example, it had been identified that one of the major cell types in the hilus, the mossy cell, innervates granule cells (GCs).

Field EPSPs of dentate gyrus granule cells studied by selective optogenetic activation of hilar mossy cells in hippocampal slices.

Unlabelled: Glutamatergic dentate gyrus (DG) mossy cells (MCs) innervate the primary DG cell type, granule cells (GCs). Numerous MC synapses are on GC proximal dendrites in the inner molecular layer (IML). However, field recordings of the GC excitatory postsynaptic potential (fEPSPs) have not been used to study this pathway selectively.

Increasing adult-born neurons protects mice from epilepsy.

Neurogenesis occurs in the adult brain in the hippocampal dentate gyrus, an area that contains neurons which are vulnerable to insults and injury, such as severe seizures. Previous studies showed that increasing adult neurogenesis reduced neuronal damage after these seizures. Because the damage typically is followed by chronic life-long seizures (epilepsy), we asked if increasing adult-born neurons would prevent epilepsy.

Choline supplementation in early life improves and low levels of choline can impair outcomes in a mouse model of Alzheimer's disease.

Maternal choline supplementation (MCS) improves cognition in Alzheimer's disease (AD) models. However, the effects of MCS on neuronal hyperexcitability in AD are unknown. We investigated the effects of MCS in a well-established mouse model of AD with hyperexcitability, the Tg2576 mouse.