Mechanisms of histamine ameliorating memory impairment induced by pentylenetetrazole-kindling epilepsy in rats / 浙江大学学报·医学版

To investigate the effects of neuronal histamine on spatial memory acquisition impairment in rats with pentylenetetrazole-kindling epilepsy, and to explore its mechanisms.A subconvulsive dose of pentylenetetrazole (35 mg/kg) was intraperitoneally injected in rats every 48 h to induce chemical kindling until fully kindled. Morris water maze was used to measure the spatial memory acquisition of the rats one week after fully pentylenetetrazole-kindled, and the histamine contents in different brain areas were measured spectrofluorometrically. Different dosages of hitidine (the precursor of histamine), pyrilamine (H1 receptor antagonist), and zolantidine (H2 receptor antagonist) were intraperitoneally injected, and their effects on spatial memory acquisition of the rats were observed.Compared with control group, escape latencies were significantly prolonged on Morris water maze training day 2 and day 3 in pentylenetetrazole-kindling epilepsy rats (all<0.05); and the histamine contents in hippocampus, thalamus and hypothalamus were decreased significantly (all<0.05). Escape latencies were markedly shortened on day 3 by intraperitoneally injected with histidine 500 mg/kg, and on day 2 and day 3 by intraperitoneally injected with histidine 1000 mg/kg in pentylenetetrazole-kindling epilepsy rats (all<0.05). The protection of histidine was reversed by zolantidine (10 and 20 mg/kg), but not by pyrilamine.Neuronal histamine can improve the spatial memory acquisition impairment in rats with pentylenetetrazole-kindling epilepsy, and the activation of H2 receptors is possibly involved in the protective effects of histamine.

Effects of crocin on hippocampus rapid kindling epilepsy in mice / 浙江大学学报·医学版

To investigate the effect of crocin on the progression and generalized seizure of temporal lobe epilepsy in mice.Hippocampus rapid kindling model was established in C57BL/6J mice. The effects of crocin on seizure stage, afterdischarge duration (ADD), number of stimulation in each stage and final state, the incidence of generalized seizure (GS), average seizure stage and ADD were observed.Crocin (20 mg/kg) significantly retarded behavioral seizure stages (<0.05) and shortened cumulative ADD (<0.01) during hippocampus rapid kindling acquisition in mice compared with vehicle group. Meanwhile, number of stimulations in stage 1-2 was significantly increased (<0.05) and the incidence of fully kindled animals was significantly decreased (<0.01). However, 10 or 50 mg/kg crocin showed no significant effect on the above indexes (all>0.05). Crocin (100 or 200 mg/kg) significantly decreased the incidence of GS (all<0.01) and reduced average seizure stages (all<0.01) in fully-kindled mice compared with vehicle group; Fifty mg/kg crocin only reduced average seizure stages (<0.05).Low-dose crocin can retard the progression in hippocampus rapid kindling acquisition in mice, while high-dose crocin relieves the GS in fully-kindled mice, which suggests that crocin may be a potential anti-epileptic compound.

Montelukast reduces seizures in pentylenetetrazol-kindled mice

Cysteinyl leukotrienes (CysLTs) have been implicated in seizures and kindling; however, the effect of CysLT receptor antagonists on seizure frequency in kindled animals and changes in CysLT receptor expression after pentylenetetrazol (PTZ)-induced kindling have not been investigated. In this study, we evaluated whether the CysLT1 inverse agonist montelukast, and a classical anticonvulsant, phenobarbital, were able to reduce seizures in PTZ-kindled mice and alter CysLT receptor expression. Montelukast (10 mg/kg, sc) and phenobarbital (20 mg/kg, sc) increased the latency to generalized seizures in kindled mice. Montelukast increased CysLT1 immunoreactivity only in non-kindled, PTZ-challenged mice. Interestingly, PTZ challenge decreased CysLT2 immunoreactivity only in kindled mice. CysLT1 antagonists appear to emerge as a promising adjunctive treatment for refractory seizures. Nevertheless, additional studies are necessary to evaluate the clinical implications of this research.

Synaptic vesicle protein2A decreases in amygdaloid-kindling pharmcoresistant epileptic rats / 华中科技大学学报（医学）（英德文版）

Synaptic vesicle protein 2A (SV2A) involvement has been reported in the animal models of epilepsy and in human intractable epilepsy. The difference between pharmacosensitive epilepsy and pharmacoresistant epilepsy remains poorly understood. The present study aimed to observe the hippocampus SV2A protein expression in amygdale-kindling pharmacoresistant epileptic rats. The pharmacosensitive epileptic rats served as control. Amygdaloid-kindling model of epilepsy was established in 100 healthy adult male Sprague-Dawley rats. The kindled rat model of epilepsy was used to select pharmacoresistance by testing their seizure response to phenytoin and phenobarbital. The selected pharmacoresistant rats were assigned to a pharmacoresistant epileptic group (PRE group). Another 12 pharmacosensitive epileptic rats (PSE group) served as control. Immunohistochemistry, real-time PCR and Western blotting were used to determine SV2A expression in the hippocampus tissue samples from both the PRE and the PSE rats. Immunohistochemistry staining showed that SV2A was mainly accumulated in the cytoplasm of the neurons, as well as along their dendrites throughout all subfields of the hippocampus. Immunoreactive staining level of SV2A-positive cells was 0.483 ± 0.304 in the PRE group and 0.866 ± 0.090 in the PSE group (P < 0.05). Real-time PCR analysis demonstrated that 2(-ΔΔCt) value of SV2A mRNA was 0.30 ± 0.43 in the PRE group and 0.76 ± 0.18 in the PSE group (P < 0.05). Western blotting analysis obtained the similar findings (0.27 ± 0.21 versus 1.12 ± 0.21, P < 0.05). PRE rats displayed a significant decrease of SV2A in the brain. SV2A may be associated with the pathogenesis of intractable epilepsy of the amygdaloid-kindling rats.

Antiepileptic effect of low-frequency electrical stimulation is waveform-dependent in hippocampal kindled mice / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate whether the waveform of electrical stimulus affects the antiepileptic effect of focal low-frequency stimulation (LFS).</p><p><b>METHODS</b>The antiepileptic effects of the LFS in sine, monophase square and biphase square waves were investigated in hippocampal kindled mice, respectively.</p><p><b>RESULTS</b>Compared to the control group, sine wave focal LFS (30 s) inhibited seizure stages (2.85 ± 0.27 vs 4.75 ± 0.12, P<0.05), lowered incidence of generalized seizures (53.6% vs 96.5%, P<0.01) and reduced afterdischarge durations [(16.2 2 ± 1.69)s vs (30.29 ± 1.12)s, P<0.01] in hippocampal kindled mice, while monophase or biphase square wave LFS (30 s) showed no antiepileptic effect. Monophase square LFS (15 min) inhibited seizure stages (3.58 ± 0.16, P<0.05) and incidence of generalized seizures (66.7%,P<0.01), but had weaker inhibitory effect on hippocampal afterdischarge durations than sine wave LFS. In addition, pre-treatment and 3 s but not 10 s post-treatment with sine wave LFS resulted in suppression of evoked seizures (P<0.05 or P<0.01).</p><p><b>CONCLUSION</b>The antiepileptic effect of LFS is dependent on its waveform. Sine wave may be optimal for closed-loop LFS treatment of epilepsy.</p>

Antiepileptic effect of low frequency stimulation in kindling rats / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the antiepileptic effects of various stimulation modes of low-frequency stimulation(LFS) on the kindling rats.</p><p><b>METHODS</b>Stimulating electrodes were implanted in the amygdala and current with constant intensity was applied to evoke kindling-induced seizures. The antiepileptic effect of LFS by open loop stimulation(before kindling), closed loop stimulation(immediately after kindling) and different forms of closed loop stimulation(whole stage after kindling and early stage after kindling) were investigated in amygdala kindled rats.</p><p><b>RESULTS</b>The closed loop LFS of whole stage after kindling can significantly inhibited seizure stages(P<0.01) and reduced afterdischarge duration(P<0.05). The closed loop LFS of early stage after kindling can significantly suppress the seizure stages, mainly in stages 0-3(P<0.05 or P<0.01). The open loop low-frequency stimulation did not inhibit the seizure stage during kindling acquisition(P>0.05).</p><p><b>CONCLUSION</b>The antiepileptic effect of low frequency stimulation may have a mode-dependent effect. It may be helpful for the deep brain stimulation as a promising approach applied to clinical antiepileptic therapy in the future.</p>

Dépendance à l'adolescence: le vide par l'excès / Dependence in adolescence: the void by excess

Le lien est perçu à la fois comme une condition et une variable de la formation psychique individuelle. Mais aussi la question qui renvoi à l'absence et à la séparation. Toutefois, pour certains adolescents si la question centrale du lien est justement la possibilité de symboliser une absence, on peut imaginer que la construction d'un lien sera toujours complexe et constituée de plusieurs aspects. Avec Daphnée, 17 ans, consommatrice de cannabis, nous allons questionner la fonction para excitante du cannabis pour que les liens intrapsychiques et symboliques puissent être préservés.

Dependence in adolescence: the vacuum by the excess. The link is perceived at the same time as a condition and a variable of the psychic, but also the question which returns to the absence and to the separation. However, for certain teenagers if the central question of the link is exactly the possibility to symbolize an absence, we can imagine that the construction of a link will always be complex and established by several aspects. With Daphnée, 17 years, consumer of cannabis, we are going to question the function para-exciting of the cannabis so that the links intra-psychics and symbolic can be protected.

Effects of thioperamide on seizure development and memory impairment induced by pentylenetetrazole-kindling epilepsy in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Histamine H(3) receptor antagonists have been considered as potential drugs to treat central nervous system diseases. However, whether these drugs can inhibit epileptogenesis remains unclear. This study aimed to investigate the effects of thioperamide, a selective and potent histamine H(3) receptor antagonist, on the seizure development and memory impairment induced by pentylenetetrazole (PTZ)-kindling epilepsy in rats.</p><p><b>METHODS</b>Chemical kindling was elicited by repeated intraperitoneal (ip) injections of a subconvulsant dose of PTZ (35 mg/kg) once every 48 hours for 12 times, and seizure activity of kindling was recorded for 30 minutes. Control rats were ip injected with saline instead of PTZ. Morris water maze was used to evaluate the spatial memory. Phosphorylated cyclic adenosine monophosphate response element binding protein (p-CREB) was tested by Western blotting in hippocampus.</p><p><b>RESULTS</b>Intracerebroventricular (icv) injections with thioperamide (10 µg, 20 µg) 30 minutes before every PTZ injections, significantly prolonged the onset of PTZ-kindling and inhibited the seizure stages. PTZ-kindling seizures led to the impairment of spatial memory in rats, and thioperamide ameliorated the impairment of spatial learning and memory. Compared to non-kindling rats, there was a significant decrease in p-CREB level in hippocampus of the PTZ-kindling rats, which was reversed by thioperamide.</p><p><b>CONCLUSIONS</b>Thioperamide plays a protective role in seizure development and cognitive impairment of PTZ-induced kindling in rats. The protection of thioperamide in cognitive impairment is possibly associated with the enhancement of CREB-dependent transcription.</p>

Effects of heterotherapy for homopathy on the metabolism path of glutamate in the pentylenetetrazol-kindled seizure rats' hippocampus / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To investigate and compare the effects of Compound Chaihu Shugan Decoction (CHSGD, "treatment from Gan") and Dingxian Pill (DXP, "treatment from the sputum") on the metabolism path of glutamate in the pentylenetetrazol-kindled seizure rats' hippocampus, thus exploring the molecular mechanism of "heterotherapy for homopathy".</p><p><b>METHODS</b>A chronic kindling seizures rat model was established by intraperitoneal injecting pentylenetetrazol (PTZ). Totally 24 fully kindled seizure rats were randomized into four groups, i.e., the model control group, the Sodium Valproate (VPA) group, the DXP group, and the CHSGD group. They were respectively treated with normal saline, VPA, CHSGD, and DXP, respectively. Rats in the control group were treated with normal saline by peritoneal injection and by gastrogavage. After intragastric administration for 4 successive weeks, the glutamate (Glu) levels in the hippocampus were detected by high performance liquid chromatography (HPLC). The expressions of glutamate transporter-1 (GLT-1) proteins were detected by Western blot. The activity of glutamine synthetase (GS) was detected by using GS detection kit.</p><p><b>RESULTS</b>Compared with the control group, the content of Glu in the model group significantly increased, and the expression of GLT-1 and the activity of GS significantly decreased (P < 0.01). Compared with the model group, the content of Glu in each medication group significantly decreased, and the protein expression of GLT-1 as well as the activity of GS significantly increased (P < 0.01). But when compared between the CHSGD group and the DXP group, the content of Glu was lower and the activity of GS was higher in the CHSGD group than in the DXP group (P < 0.01), while there was no statistical difference in the expression of GLT-1 between the two groups (P > 0.05).</p><p><b>CONCLUSIONS</b>CHSGD ("treatment from Gan") and DXP ("treatment from the sputum") could both decrease the level of Glu and raise the expression of GLT-1 and the activity of GS, indicating that CHSGD and DXP both could regulate the metabolism path of Glu to affect the level of the Glu in the brain. But the effects of CHSGD were superior to those of DXP in decreasing the content of Glu and up-regulating the activity of GS, suggesting that there were some different effects targets between the two compounds on the metabolism path of Glu, which may be one of possible molecular mechanisms for treating epilepsy by heterotherapy for homopathy.</p>

Antiepileptic and antioxidant effect of brassica nigra on pentylenetetrazol-induced kindling in mice

Considering the high rate of epilepsy today, with respect to the insufficiency of the available therapies, new strategies and methods are recommended for medical treatment of epileptic patients. Therefore, the present study experimentally investigated the anticonvulsant effect of a herbal medicine candidate brassica nigra, by using kindling method. Sixty male mice were randomly selected and divided into six experimental groups [n = 10] including: 1-control, 2-pentylentetrazole [PTZ]-kindled mice, 3-positive control group received valproate [100 mg/Kg] as anti-convulsant drug, 4-5 and 6 received brassica nigra seed extract in three doses [75, 150 and 300 mg/Kg; IP]. All groups except for the control ones were kindled by 11 period injections of PTZ [35 mg/Kg; IP]. In the 12th injection, all groups except for the control group were tested for PTZ challenge dose [75 mg/Kg]. However, the exhibited phases of seizure [0-6] were observed and noted till 30 min after the PTZ injection. At last, the brains of all the mice were removed and then malondialdehyde [MDA], superoxide dismutase [SOD] and nitric oxide [NO] levels of the brain tissues were determined. Statistical analysis of the data shows that the seed extract could reduce the intensity, improvement and duration of seizure. In addition, the brassica nigra extract increased the SOD and NO levels and decreased the MDA level in the brain tissues. Attained results show that the extract of Brassica nigra seed can be used in grand mal seizure treatment. Moreover, the antiepileptic effect of this extract is probably caused by its antioxidant properties and acts via enzyme activity mechanism

Effects of kindling epilepsy and low frequency of epileptic focus on spontaneous neuropathic pain in rats / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of epileptogenesis and low frequency stimulation at epileptic focus on spontaneous neuropathic pain in rats.</p><p><b>METHODS</b>Bipolar stimulating electrodes were implanted in the amygdala and current with constant intensity was applied to evoke kindling-induced seizures. In partial and generalized stages of seizure acquisition, neuroma model of spontaneous neuropathic pain was prepared by completely transection of the left sciatic and saphenous nerves of rats. Autotomy behavior was scored daily until d 63 postoperatively. Rats were divided into 5 groups: Control (n=7), rats with partial seizures (1-3 stages, n=5), rats with generalized seizures (4-5 stages, n=7), rats with partial seizures and low frequency stimulation(n=4), rats with generalized seizures and low frequency stimulation(n=4). Low frequency stimulation was applied to the amygdala, the epileptic focus for 21 d from the d 2 after nerve transection.</p><p><b>RESULTS</b>Autotomy level in rats with partial seizures was significantly lower than that in controls. The autotomy scores during postoperative d 40 ≊63 were significantly lower than those of controls, the area under the progression curve of autotomy behavior was decreased from 308.2 ±51.57 to 45.80 ±24.64, the onset day of autotomy was postponed by 32 d and none of the animals with partial seizures showed high autotomy, while 71.4 % of controls showed that on d 63 postoperatively. Rats with generalized seizures showed autotomy similar to controls, except that the onset day was postponed by 16 d. Autotomy behavior in rats receiving low frequency stimulation of the amygdala was not different from that in controls.</p><p><b>CONCLUSION</b>Focal seizures can lower sensitivity to spontaneous neuropathic pain in rats, while low frequency stimulation applied to the focus can abolish such effect.</p>

Effects of Wuling mycelia on pentylenetetrazole-induced epilepsy in rats / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects and mechanisms of Wuling mycelia on seizure development and learning ability induced by pentylenetetrazole-kindling epilepsy in rats.</p><p><b>METHODS</b>SD rats were randomly divided into four groups: pentylenetetrazole-kindling model group (model group), low dose Wuling mycelia (0.3 g*kg(-1)) group (LD-WM group), high dose Wuling mycelia (0.6 g*kg(-1)) group (HD-WM group) and control group. The rats were intraperitoneal injected with a subconvulsive dose (35 mg*kg(-1)) of pentylenetetrazole (saline in control group) every 48 h for 12 times. Wuling mycelia was intragastrically applied 30 min before pentylenetetrazole injection. An 8-arm radial maze ( 4 arms baited) was used to measure the learning ability. Histamine was measured by chemical fluorometric enzyme immunoassay.</p><p><b>RESULTS</b>Compared with the model group, the kindling stage of LD-WM group degraded significantly after 7th injection, the latency to the onset of myoclonic jerks (LTMJ) and the latency to the onset of generalized seizures (LTGS) prolonged after the 6th and 7th injection, respectively (P<0.05). The kindling stage of HD-WM group also degraded markedly after the 6th to 8th injection, and the LTMJ and the LTGS extended after the 8th to 9th and 6th injection, respectively (P<0.05). Compared with the control group, the frequency of working memory error (WME) and reference memory error (RME) of the model group in the 8-arm radial maze increased through 3-d training (P<0.05). The memory tests showed that the impairment induced by pentylenetetrazole was partially reversed by Wuling mycelia. Compared with the control group, brain histamine contents (hippocampus, cortex, thalamus and hypothalamus) were significantly lower in model group (P<0.05). But compared with the model group, hippocampal histamine contents in LD-WM group and hippocampal, thalamic and hypothalamic histamine contents in HD-WM group were elevated (P<0.05).</p><p><b>CONCLUSION</b>Wuling mycelia can delay the kindling and ameliorate the ability of learning in rats with pentylenetetrazole-induced epilepsy and the enhancement of neuronal histamine activity may be one of possible mechanisms.</p>

The effect of high frequency stimulation of epileptic foci on the release of glutamate and gamma-aminobutyric acid in hippocampus of the kainic acid-kindled rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the dynamics of hippocampal release of glutamate (Glu) and gamma-aminobutyric acid (GABA) in epilepsy (TLE) after administration with high frequency stimulation (HFS).</p><p><b>METHODS</b>The SD were divided into four groups (n =10): (1) Control group (KB) the rats were injected intraperitoneally with saline 0.9%. (2) Kainic acid (KA) group: the rats were injected with KA. (3) Pseudo-deep brain stimulation (DBS) group: the KA-induced rats were implanted with rheophores alone. (4) DBS group: KA induced-rats with DBS in hippocampal epileptic foci. We then collected hippocampal extracellular fluid by microdialysis and the levels of Glu and GABA were measured by high-performance liquid chromatography (HPLC) and fluorescence detection.</p><p><b>RESULTS</b>There was no difference in the baseline of Glu and GABA in the four groups. In contrast, a significant increase in the content of Glu and GABA was shown in the three periods of KA-kindled seizures. Electrical stimulation of hippocampus resulted in a decrease of hippocampal Glu contents, while there was no change in GABA contents. Additionally, HFS of hippocampus normalized the Glu/GABA ratio in the chronic period of seizures.</p><p><b>CONCLUSION</b>The high frequency stimulation of epileptic foci may protect against seizures by modulating the extracellular release of hippocampal Glu.</p>

Changes of glucocorticoid receptor mRNA expression in basolateral amygdale-kindled rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Glucocorticoid receptor (GR) is believed to be a major factor in brain maturation and in modulation of a series of brain activity. Hippocampal neurons are abundant in glucocorticoid receptor, and there is significant change in GR expression under certain pathological state. Epilepsy is a special pathological state of the central nervous system. This study aimed to explore the role of GR in epilepsy by observing the change and functions of GR in hippocampus with a basolateral amygdale-electrical kindled rat epilepsy model.</p><p><b>METHODS</b>Firstly, we established the basolateral amygdale-electrical kindled rat epilepsy model. Then GR mRNA expression in the hippocampus was assayed by semi-quantitative reverse transcription-PCR in this experiment. In addition, the processes of epileptic seizures were observed and electroencephalograms were recorded. One-way analysis of variance (ANOVA) was employed for comparing means of multiple groups, followed Fisher's least significant difference (LSD) for paired comparison.</p><p><b>RESULTS</b>The rats were successfully kindled after an average of (13.50 ± 3.99) times electrical stimulation, in which it was showed that GR mRNA expression reduced obviously as compared with the control group and the sham groups (P < 0.001). The down-regulation of GR mRNA expression was abated or reversed by some anti-epilepsy drugs (P < 0.001 compared with the epilepsy group), accompanied by attenuation of seizures and improvement of electroencephalograms.</p><p><b>CONCLUSIONS</b>Down-regulation of hippocampal GR mRNA expression may be related to the kindling. Anti-epilepsy drugs exposure can retard this change.</p>

Effects of Vitex agnus - castus extract on after- discharge threshold, seizure stages and kindling acquisition in male rats

Vitex agnus - castus extract [Vitex] is available in dosage forms for female disorders treatment. This extract has shown controversial effects against seizures induced by Maximal electroshock [MES] or pentylenetetrazole [PTZ]. In the present study the anti-seizure activity of Vitex against acquisition of amygdala kindling was evaluated in male rats. Methods: Intact male rats were stereotaxically implanted with a tripolar and 2 monopolar electrodes in amygdala and dura respectively. The threshold of AD emerging was determined in each animal. Then, Vitex or solvent was injected and AD threshold was determined again. Also, Vitex injection was continued daily and seizure stages [S1 to S5] and ADDs were recorded 30 min post Vitex injection till development of full kindling. Vitex treatment increased the AD threshold significantly more than 2.5 times and decreased the after-discharge duration [ADD]. Although, the number of trials increased significantly by Vitex for exhibition of stages 1 [S1] to S3, but this effect was not significant for development of S4 and S5 [generalized seizures]. The cumulative ADDs difference between control and Vitex group was only significant for S3 - S5. Conclusions: Vitex may induce a protective effect via increment of stimulation threshold and decrement of ADD at least against focal epilepsy in amygdala neurons. Regarding to its limited effects on kindling acquisition at late stage with generalized seizures, Vitex may postpone the progress of epileptic activity at initial stages

Effect of Chaihu Shugan Tang on excitability in different brain regions of pentylenetetrazole-kindled chronic epileptic rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of the Chinese compound prescription Chaihu Shugan Tang (CHSGT) on the excitability in the cerebral cortex and hippocampus (different brain regions) of pentetrazole (PTZ)-kindled chronic epileptic rats.</p><p><b>METHOD</b>To establish the model of chronic kindling rats intraperitoneal injected with pentylenetet. Fully kindled rats were randomized into control and experimental groups for intragastric administration of normal saline (control, model), Sodium Valproate and CHSGT at the high, medium and low doses for 4 consecutive weeks. The content of 2-NBDG, the glutamate (Glu) and the aspartate (Asp) in different brain regions of rats were detected by fluorescence imaging techniques and HPLC assay respectively.</p><p><b>RESULT</b>CHSGT at the high, medium and low doses all significantly decreased the content of 2-NBDG, the Glu and the Asp in different brain regions of chronic epileptic rats (P < 0.01).</p><p><b>CONCLUSION</b>CHSGT can inhibit the excitability in different brain regions of PTZ-induced epileptic rats, by decreasing the level of excitatory neurotransmitter maybe one of its antiepileptic mechanisms.</p>

Effect of maternal isolation stress on epilepsy susceptibility in young rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effect of maternal isolation stress on the epilepsy susceptibility in young rats and the possible mechanism.</p><p><b>METHODS</b>Sixty Sprague-Dawley young rats were randomly divided into a normal control and two maternal isolation groups that were subjected to maternal isolation for 15 min or 3 hrs daily on postnatal days 2-17. On postnatal day 18, an amygdala kindling test was performed to induce seizures. The expression of GABA(A) receptor α₁ in the hippocampus was determined by immunohistochemisty.</p><p><b>RESULTS</b>The weights were reduced, the threshold of amygdala kindling and the stimulation number for full kindling decreased significantly, and seizures were more severe in the maternal isolation 3 hrs group compared with the normal control group. The expression of GABA(A) receptor alpha(1) in the hippocampus CA1 area in the maternal isolation 3 hrs group decreased significantly compared with that in the normal groups. There were no significant differences in the aspects above mentioned between the maternal isolation 15 min and normal control groups.</p><p><b>CONCLUSIONS</b>The stress of early daily maternal isolation for 3 hrs may affect adversely brain development and increase epilepsy susceptibility in young rats. The decreased expression of GABA(A) receptor α₁ in the hippocampus may contribute to the potential mechanism.</p>

Improvement in hippocampal kindling analysis through computational processing data / Aprimorando a análise do modelo de kindling hipocampal com o auxílio de processamento computacional

The kindling phenomenon is classically investigated in epileptology research. The present study aims to provide further information about hippocampal kindling through computational processing data. Adult Wistar rats were implanted with dorsal hippocampal and frontal neocortical electrodes to perform the experiment. The processing data was obtained using the Spike2 and Matlab softwares. An inverse relationship between the number of "wet dog shakes" and the Racine's motor stages development was found. Moreover it was observed a significant increase in the afterdischarge (AD) duration and its frequency content. The highest frequencies were, however, only reached at the beginning of behavioral seizures. During the primary AD, fast transients (ripples) were registered in both hippocampi superimposed to slower waves. This experiment highlights the usefulness of computational processing applied to animal models of temporal lobe epilepsy and supports a relevant role of the high frequency discharges in temporal epileptogenesis.

O fenômeno de kindling é classicamente utilizado no campo da epileptologia experimental. Este trabalho objetiva aprofundar a análise do modelo kindling hipocampal através de processamento computacional. Ratos wistar adultos receberam eletrodos hipocampais dorsais e neocorticais frontais para a realização do experimento. O processamento dos dados encontrados foi realizado pelos softwares Matlab e Spike2. Encontrou-se uma relação inversa entre wet dog shakes e o desenvolvimento dos estágios motores de Racine. A duração e o conteúdo de freqüência das pós-descargas hipocampais aumentaram durante o processo, sendo observadas descargas de alta freqüência (ripples) em ambos os hipocampos durante as pós-descargas primárias, superimpostas a ondas lentas. As mais altas freqüências, entretanto, foram apenas atingidas com o início das crises epilépticas. A utilização de sistemas computacionais para a confecção e análise do modelo de epilepsia temporal é ressaltada e reforça-se a relevância do papel das altas freqüências na epileptogênese temporal.

Ahogamiento incompleto, valoración de la injuria cerebral al ingreso: terapia intensiva pediátrica / Nearly drowning, valuation of the cerebral injury when entering the hospital: intensive pediatric therapy

Se realizó una investigación descriptiva retrospectiva que incluyó a todos los pacientes que fueron ingresados en el Servicio de Terapia Intensiva del Hospital Eliseo Noel Caamaño, en el período comprendido desde junio de 1982 hasta junio de 2004, con el diagnóstico de Ahogamiento Incompleto, con el propósito de determinar el estado neurológico y su relación con diferentes variables que pueden haber influido en la intensidad del daño, así como la sobrevivencia final de los mismos. Los resultados obtenidos nos permitieron conocer el manejo del paciente pediátrico que ha sufrido este tipo de accidentes, así como su estado a la llegada al Servicio. El 68 por ciento de los pacientes tuvieron una afección de moderada a severa según las escalas de Conn y Glasgow, además existió una correlación de hasta un 97 por ciento entre dichos métodos de evaluación. Dentro de las variables que influenciaron en el estado de los niños al ingreso se destacó un tiempo de inmersión mayor de 5 minutos para los clasificados como severos, 70 por ciento de la muestra, fallecieron el 7 por ciento de todos los pacientes estudiados, todos ellos clasificados como severos.

We carried out a descriptive retrospective study including all the patients that were entered in the Service of Intensive Therapy of the hospital Eliseo Noel Caamaño, in the period from June 1982 to June 2004, with the diagnosis of nearly drowning, with the purpose of determining the neurological state and its relation with different variables that might have influence in the intensity of the damage, as well as in the final surviving of the patients. The obtained results allowed us knowing the managing of the paediatrics patient that have suffered this kind of accidents, as well as their state at the arrival to the service; 68 percent of the patients had a moderated to severe affection according to the Conn and Glasgow scales; moreover, there was a correlation of up to 97 percent between these evaluation methods. Among the variables that influenced in the state of the children at the entering, there was an immersion time of more than 5 minutes for those classified as severe, 70 percent of the sample; 7 percent of all the studied patients died, all of them classified as severe.

[Effect of aspirin on learning and memory impaired by pentylenetetrazole kindling in male rat]

In recent years many studies have reported that aspirin could have beneficial effect on learning and memory in different diseases of central nervous system. The objective of present study was to explore the effect of aspirin on learning and memory of Rats in pentylenetetrazole kindling model. In this experimental study Rats were divided randomly into six groups [n=8]. Animals in three groups received aspirin [15 and 30 mg/kg, orally] and saline, one week before and during induction of kindling, respectivley. Kindling was induced in these groups by administration of pentylenetetrazole [PTZ: 40 mg/kg, ip]. Two groups of animals received only aspirin 25 and 30 microg/kg orally. Other group received only saline throughout the study and served as health control group. After induction of kindling the learning and memory of Rats was tested in shuttle box. Study was divided to three stages of adaptation, acquisition and retention test. Initial Latency [IL] time before electrical shock and Step through latency [STL] time, 20 min or 24h after acquisition was evaluated as learning and memory index. Locomotor activity was also evaluated in open filed test. PTZ kindling significantly decreased Initial Latency and Step through latency time, 20 min or also 24h after acquisition, and aspirin significantly increased these times in kindled animals [p<0.05]. Aspirin also had no significant effect on locomotor activity of animals. This study showed that the administration of aspirin to kindled Rats improved learning and memory impairments induced by pentylenetetrazole kindling