Strong olfactory stimulation reduces seizure susceptibility in amygdala-kindled rats.
Seizures in human temporal lobe epilepsy are characterized by paroxysmal activity in the limbic system. The primary olfactory or piriform cortex is a central part of the limbic system. Since a relationship between olfactory sensation and limbic seizures has been described, we were interested in the effect of strong olfactory stimulation on the seizure susceptibility of amygdala-kindled rats, a model of human temporal lobe epilepsy. Olfactory stimulation with toluene was able to suppress seizures in most kindled rats after stimulation at 20% above the threshold for eliciting epileptic afterdischarges. Olfactory stimulation with toluene or ammonia increased the threshold by 27 and 25% compared to control conditions. Our data substantiate that olfactory brain regions, such as the piriform cortex, are involved in amygdala-kindled seizures and suggest that strong physiological stimulation of this nucleus interferes with on-going seizure activity in the limbic system. Thus, olfactory stimulation could contribute to anticonvulsant therapy.
Ebert
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U
Department of Pharmacology, Toxicology and Pharmacy, School of Veterinary Medicine, Hannover, Germany. uebert@pharma.tiho-hannover.de
Löscher
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W
D000641:Ammonia; D000679:Amygdala / Q000503:physiopathology*; D000818:Animals; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology*; D005260:Female; D007696:Kindling, Neurologic / Q000502:physiology*; D009812:Odorants; D009833:Olfactory Pathways / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000503:physiopathology; D012903:Smell / Q000502:physiology*; D014050:Toluene
D014050:Toluene; D000641:Ammonia