2 results
25 - Animal models of epilepsy
-
- By Ricardo M. Arida, Laboratory of Experimental Neurology Departments of Neurology and Neurosurgery Faculty of Medicine Federal University of São Paulo Rvo Botucatu 862 04023 São Paulo Brazil, Alexandre V. Silva, Laboratory of Experimental Neurology Departments of Neurology and Neurosurgery Faculty of Medicine Federal University of São Paulo Rvo Botucatu 862 04023 São Paulo Brazil, Margareth R. Priel, Laboratory of Experimental Neurology Departments of Neurology and Neurosurgery Faculty of Medicine Federal University of São Paulo Rvo Botucatu 862 04023 São Paulo Brazil, Esper A. Cavalheiro, Laboratory of Experimental Neurology Departments of Neurology and Neurosurgery Faculty of Medicine Federal University of São Paulo Rvo Botucatu 862 04023 São Paulo Brazil
- Edited by Turgut Tatlisumak, Marc Fisher
-
- Book:
- Handbook of Experimental Neurology
- Published online:
- 04 November 2009
- Print publication:
- 05 October 2006, pp 438-456
-
- Chapter
- Export citation
-
Summary
Introduction
Epilepsy is a common disorder of the brain affecting approximately 1–3% of people worldwide. Clinically, the epilepsies are characterized by spontaneous, recurrent epileptic seizures, either convulsive or non-convulsive, which are caused by partial or generalized discharges in the brain. Important advances have been made in the diagnosis and treatment of seizures disorders. Although many antiepileptic drugs (AEDs) have been introduced, approximately 30% of patients remain pharmacoresistant.
Animal models of seizures and epilepsy have played a fundamental role in the understanding of the physiological and behavioral changes associated with human epilepsy. They allow us to determine the nature of injuries that might contribute to the development of epilepsy, to observe and intercede in the disease process subsequent to an injury preceding the onset of spontaneous seizures, and also to study the chronically epileptic brain in detail, using physiological, pharmacological, molecular, and anatomical techniques.
Some criteria for a good animal model should be satisfied before the model could be considered useful for a particular human seizure or epilepsy condition. As the pattern of electroencephalograph (EEG) activity is a hallmark of seizures and epilepsy, the animal model should exhibit similar electrophysiological patterns to those observed in the human condition. The animal model should display similar pathological changes to those found in humans, it should respond to AEDs with similar mechanisms of action, and behavioral characteristics should in some way reflect the behavioral manifestations observed in humans. This chapter briefly reviews those models that most closely approximate human epilepsy.
The thalamus of the Amazon spiny rat Proechimys guyannensis, an animal model of resistance to epilepsy, and pilocarpine-induced long-term changes of protein expression
- Paolo F. Fabene, Giuseppe Bertini, Luciana Correia, Esper A. Cavalheiro, Marina Bentivoglio
-
- Journal:
- Thalamus & Related Systems / Volume 1 / Issue 2 / June 2001
- Published online by Cambridge University Press:
- 12 April 2006, pp. 117-133
- Print publication:
- June 2001
-
- Article
- Export citation
-
The thalamus of the spiny rat Proechimys guyannensis (casiragua), a common rodent of the Amazon basin, was investigated with immunohistochemistry, using as markers GABA and glutamic acid decarboxylase, and calcium binding proteins. As in all mammals, GABAergic neurons containing also parvalbumin filled the reticular nucleus, and GABAergic cells were seen in the dorsal lateral geniculate nucleus. At variance with the laboratory rat, GABAergic and parvalbumin-containing neurons were also seen in the laterodorsal and anterodorsal nuclei, in which the two markers were co-distributed. Calbindin-immunopositive cells were widely distributed in dorsal thalamic domains, except for the intralaminar nuclei, and prevailed in the laterodorsal nucleus. The distribution of calretinin-immunopositive neurons was more restricted, and they were especially concentrated in the laterodorsal and midline nuclei.
At variance with the laboratory rat, in which systemic pilocarpine administration induces status epilepticus and results in chronic limbic epilepsy, pilocarpine elicited in casiragua an acute seizure that was not followed by spontaneous seizures up to 1 month, when changes were evaluated in the thalamus using also image analysis. Parvalbumin immunostaining in reticular nucleus neurons and in the dorsal thalamus neuropil, and the number of parvalbumin-positive and GABAergic cells in the laterodorsal and anterodorsal nuclei, exhibited an increase with respect to controls. Calbindin immunostaining was also enhanced, whereas calretinin immunostaining was mostly reduced, but was preserved in midline neurons. The findings show, after an acute seizure induced in an animal model of anti-convulsant mechanisms, regional long-term neurochemical alterations that could reflect functional changes in inhibitory and excitatory thalamic neurons.