New article in “Cerebral Cortex”: Epileptic state stimulates genesis of nerve cells - Neurogenesis suspected in turn to promote epileptic activity

In a research article published in the journal Cerebral Cortex, Ute Häussler and colleagues from the group of Carola Haas provided a spatial characterisation of hippocampal areas that show epileptic activity, and juxtaposed it with areas that show cell proliferation and neurogenesis.

Using mice with kainate-induced hippocampal epilepsy as an animal model for mesial temporal lobe epilepsy in humans, the researchers combined data from the recording of local field potentials, patch-clamping individual neurons and the proliferation of cells, which was made visible through immunohistological methods.

In conclusion, the scientists could show that the epileptic state in fact triggers a spatially selective increase in neurogenesis. The promoting epileptogenic effect of these newborn cells is probably due to the fact that these young cells are easily excitable and at the same time functionally integrated into the local network of neurons. Interestingly, the zone that may be crucial for the generation of epileptic activity is suspected not to be located in the region of greatest damage to the tissue, but in a zone adjacent to it.

For the scientists, the next step will be to unravel the effect of this specific, epilepsy-promoting zone in terms of its characteristics within the network of nerve cells, for instance its feed-forward connectivity and integration mechanisms of newborn cells.

An immunohistological stain of the hippocampus makes the zone of strong neurogenesis (on the right side of the arrow) visible. In this region, epileptic activity could be detected (trace below).  

Full article (subscription required):
Ute Häussler, Lena Bielefeld, Ulrich P. Froriep, Jakob Wolfart, and Carola A. Haas (2012) Septotemporal Position in the Hippocampal Formation Determines Epileptic and Neurogenic Activity in Temporal Lobe Epilepsy Cereb. Cortex 22(1): 26-36 doi:10.1093/cercor/bhr054