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Alzheimer's Disease (AD) and epilepsy are common neurological diseases. The prevalence of epilepsy in AD patients is higher than in healthy subjects, but identifying the reasons for this association, the characteristics of seizures in AD, and the implications for prognosis and treatment is challenging. The present review provides first of all an overview of the main clinical aspects of AD and epilepsy, of their reciprocal relationship, and of the challenges that identifying seizures in AD patients presents. Limitations of clinical studies addressing this topic are discussed, including their mostly prospective nature and possible selection biases. A comprehensive, mechanistic discussion on the factors that are most likely to underlie the increased risk for seizures in AD follows. These include, for instance, GABAergic and glutamatergic alterations, Aβ and Tau protein, the role of the noradrenergic nucleus Locus Coeruleus, and neuroinflammation. Finally, evidence concerning the role that epilepsy may have in exacerbating or initiating AD is reviewed. A mechanistic insight on the relationship between epilepsy and AD might have relevant implications for improving the treatment of AD patients, as well as in elucidating pathophysiological mechanisms., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Alzheimer's Disease (AD) represents the main degenerative dementia. Its neuropathological hallmarks are β-amyloid plaques (APs) and neurofibrillary tangles (NFT), which lead to neuronal loss and brain atrophy. Recent data show that, early in the course of AD, hyperphosphorylated Tau proteins accumulate in Locus Coeruleus (LC) neuronal bodies. The fact that similar alterations have been found also in the entorhinal cortex suggests a causal relationship, although no final causal evidence exists. Later on, in the course of the disease, frank LC neuronal loss occurs, which is associated with marked cerebral NE reduction. In AD, neuroinflammation plays a pivotal role early in the process of APs deposition. LC degeneration is likely to play a key role in AD pathogenesis. In fact, NE modulates growth factors expression as well as integrity and functioning of the blood-brain barrier, and it also directly affects neuroinflammation. For instance, LC modulates microglia and astrocyte function, and this is evident following damage to LC, which induces astro- and micro-gliosis around APs, as well as interleukins secretion. These phenomena are dependent on the activation of beta-adrenergic receptors. The present review provides evidence about immune-mediated mechanisms through which LC may impact the course of AD. Some findings are consolidated in animal models. Should these data be confirmed in humans, adrenergic agents might represent potential therapeutic approaches acting on neuroinflammation to slow down the progression of AD., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Autophagy is a lysosomal catabolic route for protein aggregates and damaged organelles which in different stress conditions, such as starvation, generally improves cell survival. An impairment of this degradation pathway has been reported to occur in many neurodegenerative processes. Trimethyltin (TMT) is a potent neurotoxin present as an environmental contaminant causing tremors, seizures and learning impairment in intoxicated subjects. The present data show that in rat primary astrocytes autophagic vesicles (AVs) appeared after few hours of TMT treatment. The analysis of the autophagic flux in TMT-treated astrocytes was consistent with a block of the late stages of autophagy and was accompanied by a progressive accumulation of the microtubule associated protein light chain 3 (LC3) and of p62/SQSTM1. Interestingly, an increased immunoreactivity for p62/SQSTM1 was also observed in hippocampal astrocytes detected in brain slices of TMT-intoxicated rats. The time-lapse recordings of AVs in EGFP-mCherry-LC3B transfected astrocytes demonstrated a reduced mobility of autophagosomes after TMT exposure respect to control cells. The observed block of the autophagic flux cannot be overcome by known autophagy inducers such as rapamycin or 0.5mM lithium. Although ineffective when used at 0.5mM, lithium at higher concentrations (2mM) was able to protect astrocyte cultures from TMT toxicity. This effect correlated well with its ability to determine the phosphorylation/inactivation of glycogen kinase synthase-3β (GSK-3β)., (Copyright © 2015 Elsevier Inc. All rights reserved.)

In eukaryotic cells intracellular components are mainly degraded by autophagy and the ubiquitin-proteasome system. Autophagy is more flexible compared with the ubiquitin-proteasome system and it is involved in the degradation of long-lived proteins and organelles, such as mitochondria, which cannot be degraded by the ubiquitin-proteasome. Although autophagy is able to compensate for ubiquitin-proteasome dysfunction, the opposite does not occur. Autophagy is frequently involved in neurodegeneration; however, there is no consensus on its role in cell survival, as it can be either neuroprotective or neurotoxic. With respect to dopaminergic neurons, there is evidence that autophagy occurs during damage to substantia nigra neurons such as in Parkinson's disease. Moreover, a variety of inherited forms of Parkinson's disease are characterized by mutated proteins that belong to the autophagy pathway. Inhibition of autophagy precipitates dopaminergic cell death, whereas autophagy activation rescues the death of nigral dopaminergic neurons induced by proteasome inhibitors. Taken together, this evidence suggests that autophagy improves the survival of dopaminergic cells., (Copyright 2009 Elsevier Ltd. All rights reserved.)

To assess possible differences in dopamine metabolism that could parallel disease progression in Parkinson's disease (PD), we measured dopamine (DA) and its metabolites in the cerebrospinal fluid (CSF) in PD patients at different stages of disease: de novo (DEN), advanced not showing dyskinesias (ADV), and advanced with dyskinesias (DYS). DA, homovanillic acid (HVA) and dihydroxyphenylacetic acid (DOPAC) were significantly higher in DEN patients compared with other groups. A negative exponential correlation related DA level and disease duration. The HVA/DA ratio was significantly higher in the ADV and DYS group than that found in DEN group. Our data show that disease progression produces an early large decay of DA levels, followed by a stabilization. On the contrary, a late change in DA turnover (increased HVA/DA ratio) is documented in patients with longer disease duration. Our results suggest that the appearance of dyskinesia may not be related to a further loss of DA terminals but to a different, abnormal, DA turnover.

The major component of Lewy bodies in Parkinson's disease (PD) is alpha-synuclein, which is considered as a substrate of the ubiquitin-proteasome (UP) system, although autophagy seems to be equally involved. Here we discuss the co-existence of alpha-synuclein and proteins belonging to the UP system within autophagic granules, further developing as neuronal inclusions. We hypothesize that, following slight insults, both UP and autophagy are induced; if toxic stimuli are prolonged, these pathways are overwhelmed and cell death occurs. We then indicate a protective role of autophagy in PD and suggest it as a therapeutic target to slow down the progression of the disease.

Methamphetamine produces locomotor activation and typical stereotyped motor patterns, which are commonly related with increased catecholamine activity within the basal ganglia, including the dorsal and ventral striatum. Since the cerebellum is critical for movement control, and for learning of motor patterns, we hypothesized that cerebellar catecholamines might be a target of methamphetamine. To test this experimental hypothesis we injected methamphetamine into C57 Black mice at the doses of 5 mg/kg two or three times, 2 h apart. This dosing regimen is known to be toxic for striatal dopamine terminals. However, we found that in the cerebellum, methamphetamine increased the expression of the primary transcript of the tyrosine hydroxylase (TH) gene, followed by an increased expression of the TH protein. Increased TH was localized within Purkinje cells, where methamphetamine increased the number of TH-immunogold particles, and produced a change in the distribution of the enzyme by increasing the cytoplasmic percentage. Increased TH expression was accompanied by a slight increase in noradrenaline content. This effect was highly site-specific for the cortex of posterior vermal lobules, while only slight effects were detectable in the hemispheres. The present data indicate that the cerebellum does represent a target of methamphetamine, which produces specific and fine alterations of the catecholamine system involving synthesis, amount, and compartmentalization of TH as well as increased noradrenaline levels. This may be relevant for motor alterations induced by methamphetamine. In line with this, inherited cerebellar movement disorders in various animal species including humans are associated with increased TH immunoreactivity within intrinsic neurons of the same lobules of the cerebellar cortex.

Prion diseases include a group of either sporadic, inherited or infectious disorders characterized by spongiform neurodegeneration and reactive glyosis in several brain regions. Whatever the origin, the neuropathological hallmark of prion diseases is the presence of brain aggregates containing an altered isoform of a cellular protein, named prion protein. Recent findings show the potential toxicity of the normal cellular prion protein, which occurs when its physiological metabolism is altered. In particular, several studies demonstrate that accumulation of the prion protein in the cytosol can be a consequence of an increased amount of misfolded prion proteins, a derangement of the correct protein trafficking or a reduced activity of the ubiquitin-proteasome system. The same effects can be a consequence of a mutation in the gene coding for the prion protein. In all these conditions, one assists to accumulation and self-replication of insoluble prion proteins which leads to a severe disease resembling what observed following typical "prion infections". This article provides an opinion aimed at reconciling the classic Prusiner's theory concerning the "prion concepts" with the present knowledge arising from experimental studies on neurodegenerative disorders, suggesting a few overlapping steps in the pathogenesis of these diseases.

In recent years several clinical and research findings have demonstrated the involvement of the presynaptic protein alpha-synuclein in a variety of neurodegenerative disorders which are known as synucleinopathies. Although the function of this protein in the physiology of the cell remains unknown, it is evident that both genetic alterations or a mere overexpression of the native molecule produces a degeneration of nigral dopamine-containing neurons leading to movement disorders, as demonstrated in inherited Parkinson's disease. In the present study, we investigated whether widely abused drugs such as methamphetamine and methylenedioxymethamphetamine (ecstasy), which are known to damage the nigrostriatal dopamine pathway of mice, increase the expression of alpha-synuclein within dopamine neurons of the substantia nigra pars compacta. The results of this study demonstrate that nigrostriatal dopamine denervation and occurrence of intracellular inclusions in nigral neurons produced by amphetamine derivatives are related to increased expression of alpha-synuclein within dopamine neurons of the substantia nigra. This lends substance to the hypothesis that increased amounts of native alpha-synuclein may be per se a detrimental factor for the dopamine neurons.

This brief paper analyzes a few degenerative diseases expressing as movement disorders and featuring at sub-cellular level the presence of neuronal inclusions in selective brain regions. We will first draw a short draft of representative neurological diseases featuring inclusion bodies by describing the type of inclusions occurring in various disorders and analyzing both common features and distinctive aspects. As a further step, we move from the bed to the bench side discussing recent developments obtained from experimental models of these disorders which shed new light into the cause and progression of neuronal inclusions, thus helping to understand the pathophysiology of neuronal degeneration underlying movement disorders. In line with this, we will focus on recent studies which led to reproduce neuronal inclusions in vivo and in vitro by manipulating selective cellular structures/enzymatic pathways. In this way, we will try to encompass the dynamics of inclusion formation based on their fine ultrastructure and the analysis of the molecular components as well as their subcellular compartmentalization trying to relate the dynamics of inclusion formation and the pathophysiology of the disease process. An emphasis will be made on the ubiquitin proteasome system and Parkinson's disease where the analysis of neuronal inclusions enlightened potential therapeutic strategies to occlude the progression of this neuronal degeneration featured by movement disorders.

Seizures represent the most common neurological emergency in ecstasy abusers; however, no study addressed whether (+/-) 3,4-methylenedioxymethamphetamine ("ecstasy") per se might produce long-lasting alterations in brain excitability related to a pro-convulsant effect. C57 Black mice were treated with three regimens of (+/-) 3,4-methylenedioxymethamphetamine (5mg/kg x 2 for 1, 2 or three consecutive days). Following the last dose of (+/-) 3,4-methylenedioxymethamphetamine, during a time interval of 8 weeks, the following procedures were carried out: 1) cortical electroencephalographic recordings, including power-spectrum analysis; 2) administration of sub-threshold doses of kainate; 3) measurement of regional [(14)C]2-deoxyglucose uptake; 4) monoamine assay. We demonstrate that all mice pre-treated with (+/-) 3,4-methylenedioxymethamphetamine showed long-lasting encephalographic changes with frequencies peaking at 3-4.5 Hz at the power-spectrum analysis. This is concomitant with latent brain hyperexcitability within selected limbic brain regions, as shown by seizure facilitation and long-lasting latent metabolic hyperactivity which can be unraveled by phasic glutamate stimulation. This study sheds new light into the brain targets of (+/-) 3,4-methylenedioxymethamphetamine and discloses the occurrence of (+/-) 3,4-methylenedioxymethamphetamine-induced latent hyperexcitability within limbic areas, while it might provide a model to study in controlled experimental conditions limbic seizures and status epilepticus in C57 Black mice. Persistent changes produced by (+/-) 3,4-methylenedioxymethamphetamine in limbic brain excitability might be responsible for seizures and limbic-related disorders in chronic (+/-) 3,4-methylenedioxymethamphetamine abusers.

We investigated the expression of the substance P (SP) receptor (the neurokinin 1 receptor, NK1 receptor) and SP functional effects in developing rabbit retinas. NK1 receptors in adult retinas were in a population of cone bipolar cells and in dopaminergic amacrine cells, as previously described. In contrast, at birth and at postnatal day (PND) 6, NK1 receptors were exclusively expressed by cholinergic amacrine and displaced amacrine cells. NK1 receptor expression in cholinergic cells was still observed at PND10 (eye opening), while at PND21 it was confined to cholinergic cells of the inner nuclear layer. Starting at PND10, NK1 receptors were also in bipolar cells and in dopaminergic amacrine cells. A fully mature NK1 receptor expression pattern was observed at PND35. Dopamine release was assessed in isolated retinas in the presence of SP, the NK1 receptor agonist GR73632 or the NK1 receptor antagonist GR82334. At PND35, extracellular dopamine was significantly increased by 10 microM SP or 0.01-100 microM GR73632, and it was decreased by 0.01-10 microM GR82334. No effects were detected in developing retinas up to PND21. Ca2+ imaging experiments were performed in single cholinergic cells identified by their "starburst" morphology in perinatal retinas. Intracellular Ca2+ levels were significantly increased by 1 microM SP or GR73632. This effect was reversibly inhibited by 1 microM GR82334. These data demonstrate that both NK1 receptor expression and SP physiological actions are developmentally regulated in the retina. SP neurotransmission in the immature retina may subserve developmental events, and SP is likely to represent an important developmental factor for the maturation of retinal neurons and circuitries.

In humans, mutations in the alpha-synuclein gene or exposure to the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) produce Parkinson's disease with loss of dopaminergic neurons and depletion of nigrostriatal dopamine. alpha-Synuclein is a vertebrate-specific component of presynaptic nerve terminals that may function in modulating synaptic transmission. To test whether MPTP toxicity involves alpha-synuclein, we generated alpha-synuclein-deficient mice by homologous recombination, and analyzed the effect of deleting alpha-synuclein on MPTP toxicity using these knockout mice. In addition, we examined commercially available mice that contain a spontaneous loss of the alpha-synuclein gene. As described previously, deletion of alpha-synuclein had no significant effects on brain structure or composition. In particular, the levels of synaptic proteins were not altered, and the concentrations of dopamine, dopamine metabolites, and dopaminergic proteins were unchanged. Upon acute MPTP challenge, alpha-synuclein knockout mice were partly protected from chronic depletion of nigrostriatal dopamine when compared with littermates of the same genetic background, whereas mice carrying the spontaneous deletion of the alpha-synuclein gene exhibited no protection. Furthermore, alpha-synuclein knockout mice but not the mice with the alpha-synuclein gene deletion were slightly more sensitive to methamphetamine than littermate control mice. These results demonstrate that alpha-synuclein is not obligatorily coupled to MPTP sensitivity, but can influence MPTP toxicity on some genetic backgrounds, and illustrate the need for extensive controls in studies aimed at describing the effects of mouse knockouts on MPTP sensitivity.

Recently, we described the occurrence of a dehydroascorbate reductase within the rat CNS. This enzyme regenerates ascorbate after it is oxidized during normal aerobic metabolism. In this work, we describe the neuronal compartmentalization of the enzyme, using transmission electron microscopy of those brain areas in which the enzyme was most densely present when observed under light microscopy. In parallel biochemical studies, we performed immunoblotting and measured the enzyme activity of the cytoplasm and different nuclear fractions. Given the abundance of ascorbate in the caudate-putamen, we focused mostly on the occurrence of dehydroascorbate reductase at the striatal subcellular level. We also studied cerebellar Purkinje cells, hippocampal CA3 pyramidal cells and giant neurons in the magnocellular part of the red nucleus. In addition to neurons, immunolabeling was found in striatal endothelial cells, in the basal membrane of blood vessels and in perivascular astrocytes. In neuronal cytosol, the enzyme was observed in a peri-nuclear position and on the nuclear membrane. In addition, in both the striatum and the cerebellum, we found the enzyme within myelin sheets. Dehydroascorbate reductase was also present in the nucleus of neurons, as further indicated by measuring enzyme activity and by immunoblotting selected nuclear fractions. Immunocytochemical labeling confirmed that the protein was present in isolated pure nuclear fractions. Given the great amount of free radicals which are constantly generated in the CNS, the discovery of a new enzyme with antioxidant properties which translocates into neuronal nuclei appears to be a potential starting point to develop alternative strategies in neuroprotection.

Previous studies have shown that physiological stimulation of brain activity increases anaerobic glucose consumption, both in humans and in experimental animals. To investigate this phenomenon further, we measured extracellular lactate levels within different rat brain regions, using microdialysis. Experiments were performed comparing the effects of natural, physiological olfactory stimulation of the limbic system with experimental limbic seizures. Olfactory stimulation was carried out by using different odors (i.e. both conventional odors: 2-isobutyl-3-methoxypyrazine, green pepper essence; thymol; and 2-sec-butylthiazoline, a sexual pheromone). Limbic seizures were either induced by systemic injection of pilocarpine (200-400 mg/kg) or focally elicited by microinfusions of chemoconvulsants (bicuculline 118 pmol and cychlothiazide 1.2 nmol) within the anterior piriform cortex. Seizures induced by systemic pilocarpine tripled lactic acid within the hippocampus, whereas limbic seizures elicited by focal microinfusion of chemoconvulsants within the piriform cortex produced a less pronounced increase in extracellular lactic acid. Increases in extracellular lactate occurring during olfactory stimulation with the sexual pheromone (three times the baseline levels) were non-significantly different from those occurring after systemic pilocarpine. Increases in lactic acid following natural olfactory stimulation were abolished both by olfactory bulbectomy and by the focal microinfusion of tetrodotoxin, while they were significantly attenuated by the local application of the N-methyl-D-aspartate antagonist AP-5. Increases in hippocampal lactate induced by short-lasting stimuli (olfactory stimulation or microinfusion of subthreshold doses of chemoconvulsants, bicuculline 30 pmol) were reproducible after a short delay (1 h) and cumulated when applied sequentially. In contrast, limbic status epilepticus led to a long-lasting refractoriness to additional lactate-raising stimuli and there was no further increase in lactate levels when the olfactory stimulation was produced during status epilepticus. Increases in lactic acid following olfactory stimulation occurred with site specificity in the rhinencephalon (hippocampus, piriform and entorhinal cortex) but not in the dorsal striatum. Site specificity crucially relied on the quality of the stimulus. For instance, other natural stimuli (i.e. tail pinch) produced a similar increase in extracellular lactate in all brain areas under investigation. The major conclusion of this work is that the presentation of an odor known to be a rat pheromone results in lactate production as great as that induced by the systemic convulsant pylocarpine (maximum: 2.286+/-0.195 mM and 1.803+/-0.108 mM, respectively). This supports the notion that the great magnitude of lactate production known to accompany seizures can result from the intensified neural activity per se ("aerobic gycolysis"), not merely from local anoxia or other pathological changes.

In this study, we describe for the first time the occurrence, within the central nervous system of the rat, of a dehydroascorbate reductase analogous to the one we recently described in the liver. Dehydroascorbate reductase plays a pivotal role in regenerating ascorbic acid from its oxidation product, dehydroascorbate. In a first set of experiments, we showed that a dehydroascorbate reductase activity is present in brain cytosol; immunoblotting analysis confirmed the presence of an immunoreactive cytosolic protein in selected brain areas. Immunotitration showed that approximately 65% of dehydroascorbate reductase activity of brain cytosol which was recovered in the ammonium sulphate fraction can be attributed to this enzyme. Using immunohistochemistry, we found that a variety of brain areas expresses the enzyme. Immunoreactivity was confined to the gray matter. Amongst the several brain regions, the cerebellum appears to be the most densely stained. The enzyme was also abundant in the hippocampus and the olfactory cortex. The lesion of norepinephrine terminals following systemic administration of DSP-4 markedly decreased immunoreactivity in the cerebellum. Apart from the possible co-localization of the enzyme with norepinephrine, the relative content of dehydroascorbate reductase in different brain regions might be crucial in conditioning regional sensitivity to free radical-induced brain damage. Given the scarcity of protective mechanisms demonstrated in the brain, the discovery of a new enzyme with antioxidant properties might represent a starting-point to increase our knowledge about the antioxidant mechanisms operating in several central nervous system disorders.

The deep rostral piriform cortex contains a site (area tempestas) in which focal application of picomole amounts of bicuculline, a GABA antagonist, triggers limbic motor seizures which are dependent upon activation of both N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyloxole-4-proprionate subtypes of glutamate receptors. In the present study we determined whether nitric oxide can influence the local modulation of seizure initiation by bicuculline. Nitric oxide and the nitric oxide precursor L-arginine, alone or in combination with low doses of bicuculline were focally administered into the area tempestas of rats. While nitric oxide alone had no significant convulsant effect, L-arginine alone (30-240 nmol) induced brief myoclonic episodes. Nitric oxide (0.7 nmol) and L-arginine (30 nmol) markedly potentiated the seizures evoked by a low dose of bicuculline. The effect of L-arginine was prevented by focal pretreatment with an inhibitor of nitric oxide synthesis, N-nitro-L-arginine methyl ester. However, N-nitro-L-arginine methyl ester did not attenuate the convulsant effect of bicuculline or kainate alone when focally administered into area tempestas. The data demonstrate that exogenously applied nitric oxide or its precursors can enhance seizure triggering activity. However, the data also indicate that L-arginine-nitric oxide pathway does not normally contribute to seizure expression from area tempestas, as N-nitro-L-arginine methyl ester alone did not attenuate focally-evoked seizures.

Evidence is accumulating that norepinephrine depletion enhances the neurotoxic effect of the parkinsonism inducing neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In this study we investigated whether norepinephrine loss potentiates methamphetamine-induced striatal dopamine depletion. Injection of C57BL/6N mice with methamphetamine (2 x 5 mg/kg i.p., at 2-h intervals) produced only a partial (50%) striatal dopamine depletion 7 days after drug administration. Pretreatment with the selective noradrenergic neurotoxin N-(-2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4; 50 mg/kg i.p.) enhanced methamphetamine-induced striatal dopamine depletion by 86%, without decreasing striatal dopamine levels when injected alone. Our results extend previous findings obtained with the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine in DSP-4-pretreated mice.

The chemical structure corresponding to 1-hydroxy[1,1'-bicyclohexyl]-2-carboxylic acid 2-(diethylamino)-1-methylethyl ester has the classical profile of ester-type antimuscarinic drugs. The presence of three chiral carbons leads to eight stereoisomers and the substitutions on the cyclohexyl ring generate cis-isomers (1, named rociverine) and trans-isomers (2). The aim of this study was to determine the binding pattern of the eight stereoisomers and two derived compounds, (1S,2S)-1-hydroxy[1,1'-bicyclohexyl]-2-carboxylic acid 2-(dimethylamino)-1-ethyl ester (3) (1S,2S)-1-hydroxy[1,1'-bicyclohexyl]-2-carboxylic acid (S)-2-(diethylamino)-1-methylethyl ester methyl iodide (4), at the five cloned muscarinic receptors stably expressed in chinese hamster ovary cells, in order to define how stereochemical modifications could affect the affinity. Our data showed that cis-stereoisomers exhibited higher variations in affinity than trans-stereoisomers. Among the cis-stereoisomers, those with the (1R,2R) configuration showed considerably higher affinities (up to 240-fold) than those with the (1S,2S) configuration. The (1S,2S) configuration was important for binding selectivity; this was confirmed also by the use of the two additional compounds.

Sodium lactate (pH 7.0) infused over the area tempestas, an epileptogenic site in the prepiriform cortex, protected rats from limbic motor seizures induced by infusion of a GABA receptor antagonist in area tempestas. The anticonvulsant action, which was anatomically site-specific and reversible, persisted for 90 min. Infusions of sodium acetate (pH 5.5 or 7.0) over area tempestas were not anticonvulsant. Our findings suggest that lactate can modulate neural activity and that increased cerebral lactate as occurs with epileptic seizures, may limit the duration and spread of seizure activity.