Search results for "Maximal dentate activation"
showing 7 items of 7 documents
Neuronal nitric oxide synthase is involved in CB/TRPV1 signalling: Focus on control of hippocampal hyperexcitability
2017
Cannabinoids (CB), transient receptors potential vanilloid type 1 (TRPV1) and nitric oxide (NO) were found to be interlinked in regulating some neuronal functions such as membrane excitability and synaptic transmission. TRPV1 play a fundamental role since it represents a synaptic target for CB that triggers several downstream cellular pathways. In this regard, recent evidence report that TRPV1 could influence NO production by modulating neuronal NO synthase (nNOS) activity. In the present research, we pointed to manipulate nNOS function to assess its role on TRPV1 signalling in hyperexcitability conditions elicited in the dentate gyrus of hippocampal formation. The activation of TRPV1 recep…
Antiepileptic effect of dimethyl sulfoxide in a rat model of temporal lobe epilepsy.
2012
Dimethyl sulfoxide (DMSO) is an amphipathic molecule widely used to solubilize water-insoluble compounds. In many studies it was reported that DMSO is capable of affecting several biological processes, thus resulting in a potential cause for the misinterpretation of experimental data. Recent papers showed that DMSO modified the brain bioelectric activity in animal models of epilepsy. In an in vivo model of temporal lobe epilepsy in the rat, we examined the effects of different doses (10%, 50% and 100%) of DMSO on the maximal dentate activation (MDA). The results show that DMSO induced a dose-dependent significant reduction of the electrically induced paroxysmal activity.
Evidences of cannabinoids-induced modulation of paroxysmal events in an experimental model of partial epilepsy in the rat.
2009
The anticonvulsant effect of cannabinoids (CB) has been shown to be mediated by the activation of the CB(1) receptor. This study evaluates the anticonvulsant activity of (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo[1,2,3-de]-1,4-benzoxazin-6-Yl]-1-naphthalenylmethanone (WIN55,212-2, CB agonist) alone or preceded by the administration of N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251, selective CB(1) antagonist) in an experimental in vivo model of complex partial seizures (maximal dentate gyrus activation - MDA) in the rat. WIN55,212-2 (21mgkg(-1)) exerted an anticonvulsant effect, significantly reduced by the pre-treatme…
Involvement of nitric oxide-soluble guanylyl cyclase pathway in the control of maximal dentate gyrus activation in the rat.
2006
Summary Nitric oxide=soluble Guanylyl cyclase (NO=sGC) pathway on the maximal dentate gyrus activation (MDA) was studied in rats. The cerebral NO levels were modified by administrating 7-Nitroindazole (7-NI), a selective inhibitor of neuronal NOS, and L-arginine, a precursor of the synthesis of NO. 1H-[1,2,4]Oxadiazole[4,3-a]quinoxalin-1-one (ODQ), a specific inhibitor of the NO-sGC pathway, was administered to study the involvement of cGMP pathway. The epileptic activity of the dentate gyrus was obtained through the repetitive stimulation of the angular bundle; MDA parameters studied were: onset time, MDA duration and post-stimulus afterdischarge (AD) duration. 7-NI caused an increase of M…
In the rat maximal dentate activation model of partial complex epilepsy, the anticonvulsant activity of levetiracetam is modulated by nitric oxide-ac…
2009
The effects of nitric oxide-active drugs on the anticonvulsant action of the antiepileptic drug levetiracetam in an experimental model of partial complex seizures named maximal dentate gyrus activation were studied in rats. Levetiracetam was given alone or in combination with 7-nitroindazole, a preferential inhibitor of neuronal nitric oxide synthase, or with L: -arginine, the precursor of nitric oxide synthesis. The maximal dentate activation parameters were the time of latency and the durations of maximal dentate activation and afterdischarge responses. The administration of levetiracetam showed an anticonvulsant effect that was increased when given in combination with 7-nitroindazole. Th…
Evidences of cannabinoids-induced modulation of paroxysmal events in an experimental model of partial epilepsy in the rat
2010
Different studies have been shown a clear anticonvulsant activity exerted by cannabinoids (CB) through the CB1 receptor activation. The purpose of this study was to evaluate, in an in vivo experimental model of temporal lobe epilepsy (maximal dentate gyrus activation - MDA) in the rat, the protective effect of (R)-(+)-[2,3-Dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo[1,2,3-de]-1,4-benzoxazin-6-Yl]-1-naphthalenylmethanone (WIN 55,212-2, CB agonist) alone or in combination with N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251, selective CB1 antagonist). Pre-treatment with AM251 (1 mg kg-1, 30 min interval) dramatically reduced the signif…
Hippocampal hyperexcitability is modulated by microtubule-active agent: evidence from in vivo and in vitro epilepsy models in the rat
2016
The involvement of microtubule dynamics on bioelectric activity of neurons and neurotransmission represents a fascinating target of research in the context of neural excitability. It has been reported that alteration of microtubule cytoskeleton can lead to profound modifications of neural functioning, with a putative impact on hyperexcitability phenomena. Altogether, in the present study we pointed at exploring the outcomes of modulating the degree of microtubule polymerization in two electrophysiological epileptiform activity in the rat hippocampus. To this aim, we used in vivo Maximal Dentate Activation (MDA) and in vitro hippocampal epileptiform bursting activity (HEBA) paradigms to asse…