Vesicular acetylcholine transporter knock-down mice are more susceptible to pilocarpine induced status epilepticus.
The pilocarpine (PILO) animal model of Temporal Lobe Epilepsy (TLE) portrays the most common changes in hippocampal circuitry found in human TLE. The acute cholinergic insult induces status epilepticus (SE), which triggers an overwhelming set of plastic events that result on late spontaneous recurrent limbic seizures. It has been suggested that the cholinergic system plays an important role in the synchronization required for ictogenesis. We took advantage of a knock-down animal model for the vesicular acetylcholine transporter (VAChT KD) to investigate seizure genesis in a model of cholinergic dysfunction. We induced SE in VAChT KD and wild-type (WT) mice by a single intraperitoneal injection of PILO in order to evaluate susceptibility to seizures. Video-EEG recordings evaluated epileptiform activity and ictal behavior onset. The hypothesis tested is that innate cholinergic hypofunction could result in increased susceptibility to PILO. VAChT KD(HOM) mice showed shorter latency for the first epileptiform discharge and for the first seizure episode, when compared to other groups. The duration of these seizure episodes, however, were not statistically different among experimental groups. On the other hand, VAChT KD(HOM) had the shortest latency to isoelectric EEG, when compared to WT and KD(HET). Our results indicate that a reduction of brain VAChT protein to the levels found in VAChT KD(HOM) mice alters the epileptic response to PILO. Thus, fine-tuning modulation of cholinergic tone can affect the susceptibility of epileptic responses to pilocarpine.
Guidine
Patrícia A M
PA
Núcleo de Neurociências, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Avenida Antônio Carlos 6627, CEP 31270-901 Campus Pampulha, Belo Horizonte, MG, Brazil.
Rezende
Gustavo H S
GH
Queiroz
Cláudio M T
CM
Mello
Luiz Eugênio
LE
Prado
Vânia F
VF
Prado
Marco A M
MA
Pereira
Grace S
GS
Moraes
Márcio F D
MF
D000818:Animals; D004195:Disease Models, Animal; D004198:Disease Susceptibility; D051379:Mice; D018345:Mice, Knockout; D010862:Pilocarpine; D013226:Status Epilepticus / Q000139:chemically induced* / Q000235:genetics; D050494:Vesicular Acetylcholine Transport Proteins / Q000172:deficiency*
D050494:Vesicular Acetylcholine Transport Proteins; D010862:Pilocarpine