Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Botulinum neurotoxins (BoNTs) are well recognized to cause potent, selective, and long-lasting neuroparalytic actions by blocking cholinergic neurotransmission to muscles and glands. There is evidence that BoNT isoforms can also inhibit neurotransmission in the brain. In this study, we examined whether locally delivered BoNT/A and BoNT/B can attenuate kindling measures in amygdala-kindled rats. Male rats were implanted with a combination infusion cannula-stimulating electrode assembly into the right basolateral amygdala. Fully kindled animals received a single infusion of vehicle or BoNT/A or BoNT/B at doses of 1, 3.2, or 10 ng over a 20-minute period by convection-enhanced delivery. Electrographic (EEG) and behavioral kindling measures were determined at selected times during the 3- to 64-day period after the infusion. BoNT/B produced a dose-dependent elevation in after-discharge threshold and duration and a reduction in the seizure stage and duration of behavioral seizures that lasted for up to 50 days after infusion. BoNT/A had similar effects on EEG measures; behavioral seizure measures were also reduced, but the effect did not reach statistical significance. The effects of both toxins on EEG and behavioral measures progressively resolved during the latter half of the observation period. Animals gained weight normally, maintained normal body temperature, and did not show altered behavior. This study demonstrates for the first time that locally delivered BoNTs can produce prolonged inhibition of brain excitability, indicating that they could be useful for the treatment of brain disorders, including epilepsy, that would benefit from long-lasting suppression of neurotransmission within a circumscribed brain region.
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PMID:Long-lasting attenuation of amygdala-kindled seizures after convection-enhanced delivery of botulinum neurotoxins a and B into the amygdala in rats. 2377 62

Botulinum neurotoxins are metalloproteases that specifically cleave N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in synaptic terminals, resulting in a potent inhibition of vesicle fusion and transmitter release. The family comprises different serotypes (BoNT/A to BoNT/G). The natural target of these toxins is represented by the neuromuscular junction, where BoNTs block acetylcholine release. In this review, we describe the actions of botulinum toxins after direct delivery to the central nervous system (CNS), where BoNTs block exocytosis of several transmitters, with near-complete silencing of neural networks. The use of clostridial neurotoxins in the CNS has allowed us to investigate specifically the role of synaptic activity in different physiological and pathological processes. The silencing properties of BoNTs can be exploited for therapeutic purposes, for example to counteract pathological hyperactivity and seizures in epileptogenic brain foci, or to investigate the role of activity in degenerative diseases like prion disease. Altogether, clostridial neurotoxins and their derivatives hold promise as powerful tools for both the basic understanding of brain function and the dissection and treatment of activity-dependent pathogenic pathways.
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PMID:Exploiting Botulinum Neurotoxins for the Study of Brain Physiology and Pathology. 2969

Botulinum neurotoxins (BoNTs) block the release of a series of neurotransmitters, which are pivotal for neuron action. Intrahippocampal administration of BoNTs inhibits glutamate release, protects neurons against cell death, and attenuates epileptic seizures. Compared with intrahippocampal administration, intranasal delivery is less invasive and more practical for chronic drug administration. To assess whether intranasal administration is feasible, we examined the role of botulinum neurotoxin A (BoNT/A) in hippocampal neuronal injury after status epilepticus (SE) induced by pilocarpine. Our data showed BoNT/A could bypass the blood-brain barrier (BBB) and entered the olfactory bulb and hippocampal neurons. In addition, SE could result in up-regulation of pro-apoptotic proteins (Caspase-3, Bax), down-regulation of anti-apoptotic protein Bcl-2 and neuronal death in hippocampus. BoNT/A could suppress the expression of Caspase-3 and Bax, attenuate the decrease of Bcl-2, and inhibit hippocampal neuron death induced by SE. Meanwhile, there was no significant difference in cognitive behavior between the BoNT/A-pretreated rats and normal rats. Thus, we provided a more convenient and less invasive route for taking advantage of BoNT/A in the field of anti-epilepsy.
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PMID:Intranasal Delivery of Botulinum Neurotoxin A Protects against Hippocampal Neuron Death in the Lithium-Pilocarpine Rat Model. 3087 18