Animal models epilepsies

Specific animal models are discussed in some detail in the appropriate chapters on epilepsy, depression, schizophrenia, etc. 

Since the early 1980s, much effort has focused on animal models of acute and chronic neurodegeneration in search of therapeutics for stroke. Neuronal cell death follows strokes, acute ischemic insults, and chronic neurodegeneration, such as Parkinson s disease, Alzheimer s disease (AD), epilepsy, and Huntington s disease. Up to 80% of all strokes result from focal infarcts and ischemia in the middle cerebral artery (MCA), so the commonly used animal models for neuroprotection are produced by temporary or permanent occlusion of the MCA.5 Lesions of the MCA include occlusion by electrocoagulation, intraluminal monofilaments, photochemical effects, thrombosis, and endothelin-1, but all of these models necessitate studying reperfusion events and validating MCA occlusion by behavioral assessments. 

Oxcarbazepine is less potent than carbamazepine, both in animal models of epilepsy and in epileptic patients clinical doses of oxcarbazepine may need to be 50% higher than those of carbamazepine to obtain equivalent seizure control. Some studies report fewer hypersensitivity reactions to oxcarbazepine, and cross-reactivity with carbamazepine does not always occur. Furthermore, the drug appears to induce hepatic enzymes to a lesser extent than carbamazepine, minimizing drug interactions. Although hyponatremia may occur more commonly with oxcarbazepine than with carbamazepine, most adverse effects that occur with oxcarbazepine are similar in character to reactions reported with carbamazepine. 

Mode of action. Initially the experimental studies were undertaken on the racemic mixture which contained the R- and the S-enantiomers of etiracetam. Only the S-enantiomer was shown to have antiepileptic potential in a wide range of animal models of epilepsy. It was shown to be particularly active in the kindling models but the precise action of this drug at the cellular level is uncertain. 

Schwarzer, C., Kofler, N. and Sperk, G. (1998). Up-regulation of neuropeptide Y-Y2 receptors in an animal model of temporal lobe epilepsy. Mol. Pharmacol. 53(1), 6-13. 

Animal Models of Geriatric Epilepsy Lauren J. Murphree, Lynn M. Rundhaugen, and Kevin M. Kelly... 

Blockade of the 5-HT7 receptor has been shown to reduce epileptic activity in animal models. Audiogenic seizures induced in DBA/2J mice could be prevented by drugs in a rank order of potency corresponding to their affinity for the 5-HT7 receptor (95). The selective 5-HT7 receptor antagonist SB-258719 has been shown to reduce epileptic activity in an animal model for absence epilepsy, the WAG/Rij rat (65). It is believed to do so by modulating the pacemaker current Ih within the thalamus (96,97). The 5-HT7 receptor has been demonstrated to mediate depolarization within the anterodorsal thalamus by increasing lh through a cAMP-dependent, PKA-independent mechanism (96,97). 

Fujita, T, Tanaka, T, Yonemasu, Y, Cendes, E, Cashman, N.R., and Andermann, F. 1996. Electroclinical and pathological studies after parenteral administration of domoic acid in freely moving nonanesthetized rats an animal model of excito-toxicity. J Epilepsy 9, 87-93. 

Kunieda T, Zuscik MJ, Boongird A, Perez DM, Liiders HO, Najm IM. Systemic overexpression of the a1B-adrenergic receptor in mice an animal model of epilepsy. Epilepsia 2002 43 1324-1329. 

More data in animal models with focal epilepsy are needed to determine long-term applicability (198). 

Sclerocarya birrea (A. Rich.) Hochst. subsp. cafffra [umganu, marula tree] (Sond.) Kokwaro (Anacardiaceae) stem bark decoction is used for diarrhoea. The stem bark contains alkaloids, flavonoids, glycosides, polyphenols, steroids and tannins 15). Its antidiarrhoeic activity is due to the tannin content 37). The plant is also used for childhood convulsion and epilepsy, and its anticonvulsant activity has been demonstrated in experimental animal model (58). 

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