Electroconvulsive seizure-induced expression change in the dentate gyrus of the hippocampus in mice as an index of the neuronal responsiveness in vivo.. Mus musculus

The dentate gyrus (DG) of the hippocampus is one of major targets for antidepressant treatments. Using electroconvulsive stimulation (ECS), a model of highly effective and fast-acting antidepressant therapy, here we show that neural stimulation via ECS induces rapid and lasting dematuration of granule neurons in DG. A single time of stimulation transiently reduced mature marker expression and mature synaptic functions. Repetitive stimulation converted this transient dematuration into a stable form lasting more than 1 month. We compared the activity-dependent neuronal responsiveness in the DG between a single ECS and repeated ECS. Overall design: The dentate gyrus was dissected 1h after a single sham, a single ECS or 11 times of ECS, or 48h after 10 times of ECS ( n= 3, each group). Total RNA was extracted by using an RNeasy micro kit (Qiagen) and the samples of the same groups were put together. From each group, 100 ng of total RNA was mixed and amplified with 3?IVT Express kit (Affymetrix, Inc., Santa Clara, CA, USA). All samples were hybridized to the GeneChip mouse genome 430A 2.0 array (Affymetrix, Inc.), and the microarray suite 5.0 of the Affymetrix gene chip operating software was used for the analysis of the GeneChip data.