Читать книгу Canine and Feline Epilepsy - Luisa De Risio - Страница 15

Collective anatomic or physiologic neuronal alterations might produce progressive, network-dependent facilitation of excitability, perhaps coupled with a decrease of inhibitory influences, e.g. due to selective loss of inhibitory neurons. Mossy fibre sprouting (MFS) is an example of neuronal alterations leading to increased excitability (Cavazos et al., 1991). MFS was demonstrated in patients with refractory temporal lobe epilepsy with hippocampal sclerosis on neuroimaging as well as in numerous animal models of temporal lobe epilepsy (Sutula et al., 1988, 1989). In normal conditions, the dentate granule cells limit seizure propagation through the hippocampal network. However, the formation of recurrent excitatory synapses between dentate granule cells, as is thought to occur after MFS, may transform the dentate granule cells into an epileptogenic population of neurons (McNamara, 1999). Possibly, a vicious cycle develops: seizures cause neuronal death, which results in MFS, which in turn increases seizure frequency.