Effect of brain-stem lesions on metrazol-induced seizures in cats

Jinnai, Dennosuke; Mogami, Heitaro; Mukawa, Jiro; Iwata, Yutaka; Kobayashi, Kazunobu

doi:10.1016/0013-4694(69)91449-7

Cited by 41 publications

(24 citation statements)

References 17 publications

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“…Indeed, large lesions involving the MT were not protective. Although seemingly paradoxical, this observation can be understood in light of the accumulated evidence demonstrating both facilitatory and inhibitory influences in the diencephalon on the expression of seizures (Andy and Mukawa, 1959;Gellhom et al, 1959;Milhorat et al, 1966;Jinnai et al, 1969;Gloor et al, 1977;Quesney et al, 1977). The failure of such large ablations to attenuate the PTZ convulsions suggests that destruction of other neuronal structures near the MT has an opposite, facilitatory effect on the expression of generalized seizures.…”

Section: Discussionmentioning

confidence: 98%

“…In our middiencephalic lesion experiments, the volume difference between the composite of all MT lesions and of the most protective MT lesions yields a region of brain that may be presumed to include a powerful inhibitory influence on seizure expression. Within this volume are several structures-such as the thalamic ventrolateral and centromedian nuclei, anterior hypothalamus, and dorsorostral midbrain-that have been previously associated with inhibition of paroxysmal activity (Milhorat et al, 1966;Jinnai et al, 1969). The severe limitation on the extent of the damaged area was not apparent in the FX lesions.…”

Section: Discussionmentioning

confidence: 99%

“…Early studies demonstrated numerous facilitatory and inhibitory influences on seizure activity in both the brain stem and diencephalon (Morison and Dempsey, 1942;Jasper and Droogleever-Fortuyn, 1946;Hunter and Jasper, 1949; Ingvar, 1955a, b;Ralston and Ajmone-Marsan, 1956;Kriendler et al, 1958;Andy and Mukawa, 1959; Bergman et al, 1963;Guerrero-Figueroa et al, 1963;Weir, 1964) and suggested important roles for diffusely organized regions such as the reticular formations of the pons, mesencephalon, and thalamus. Specific areas of the subcortex have also been associated with seizure mechanisms, including the hypothalamus (Murphy and Gellhorn, 1945;Jasper and Droogleever-Fortuyn, 1946; Green and Received Jan. 13, 1986; revised Aug. 28, 1986; accepted Sept. 4, 1986 (Jinnai, 1966;Jinnai et al, 1969;Jinnai and Mukawa, 1970), substantia nigra (Iadarola and Gale, 1982;Garant and Gale, 1983;Gonzalez and Hettinger, 1984; McNamara et al, 1983McNamara et al, , 1984, and several thalamic nuclei (Mullen et al, 1967;Jinnai et al, 1969;Feeney and Gullotta, 1972;Kusske et al, 1972;Van Straaten, 1975;Quesney et al, 1977).Recently we observed the selective metabolic activation of the mammillary bodies (MB) and their immediate connections during a threshold convulsive stimulus induced by the co-infusion of pentylenetetrazol (PTZ) and ethosuximide (ESM) (Mirski and Ferrendelli, 1983). We also reported preliminary data demonstrating that the interruption of the mammillothalamic tracts (MT), bilaterally, had a substantial protective effect against the convulsant PTZ (Mirski and Ferrendelli, 1984a, b).…”

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confidence: 99%

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Interruption of the connections of the mammillary bodies protects against generalized pentylenetetrazol seizures in guinea pigs

Ma¹,

Ja²

1987

J. Neurosci.

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Electrolytic lesions in the anterior and mid-diencephalon and ventral midbrain in guinea pigs were produced to examine the effects of interruption of the fornix (FX), mammillothalamic tracts (MT), and mammillary peduncles (MP), respectively, on the expression of pentylenetetrazol (PTZ) seizures. As a group, all mid-diencephalic lesioned animals had some degree of protection from the electroencephalographic and behavioral convulsant and lethal effects of the drug. Through a composite volume analysis of protected versus unprotected animals, as well as a retrospective comparison between MT and non-MT lesioned animals, it was demonstrated that small mid-diencephalic lesions incorporating only the MTs and their immediate vicinity were capable of completely preventing the convulsant and lethal effects of PTZ. Lesions of the FX and MP were also protective against PTZ seizures but to a lesser degree than the MT lesions.These results demonstrate that the major afferent and efferent connections of the mammillary bodies are involved in expressing PTZ seizure activity and suggest that the MT may be the major pathway mediating paroxysmal activity from brain stem to the thalamus.The expression of generalized seizures is characterized by bilateral and synchronous activation of cortical and subcortical brain regions. Although the functional anatomy of this convulsive process is yet unclear, substantial evidence suggests that subcortical brain regions, through their widespread cortical connections, play a major role in the propagation and perhaps initiation of these attacks. Early studies demonstrated numerous facilitatory and inhibitory influences on seizure activity in both the brain stem and diencephalon (Morison and Dempsey, 1942;Jasper and Droogleever-Fortuyn, 1946;Hunter and Jasper, 1949; Ingvar, 1955a, b;Ralston and Ajmone-Marsan, 1956;Kriendler et al., 1958;Andy and Mukawa, 1959; Bergman et al., 1963;Guerrero-Figueroa et al., 1963;Weir, 1964) and suggested important roles for diffusely organized regions such as the reticular formations of the pons, mesencephalon, and thalamus. Specific areas of the subcortex have also been associated with seizure mechanisms, including the hypothalamus (Murphy and Gellhorn, 1945;Jasper and Droogleever-Fortuyn, 1946; Green and Received Jan. 13, 1986; revised Aug. 28, 1986; accepted Sept. 4, 1986 (Jinnai, 1966;Jinnai et al., 1969;Jinnai and Mukawa, 1970), substantia nigra (Iadarola and Gale, 1982;Garant and Gale, 1983;Gonzalez and Hettinger, 1984; McNamara et al., 1983McNamara et al., , 1984, and several thalamic nuclei (Mullen et al., 1967;Jinnai et al., 1969;Feeney and Gullotta, 1972;Kusske et al., 1972;Van Straaten, 1975;Quesney et al., 1977).Recently we observed the selective metabolic activation of the mammillary bodies (MB) and their immediate connections during a threshold convulsive stimulus induced by the co-infusion of pentylenetetrazol (PTZ) and ethosuximide (ESM) (Mirski and Ferrendelli, 1983). We also reported preliminary data demonstrating that the interruption of the mamm...

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Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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Interruption of the connections of the mammillary bodies protects against generalized pentylenetetrazol seizures in guinea pigs

Ma¹,

Ja²

1987

J. Neurosci.

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“…Whether one subscribes to the centrencephalic concept of generalized epilepsy, or the tenet of cortical predominance in seizure spread, it has been clear that subcortical-cortical interactions modulate the early sequences leading to global ictal events (1,2,4,5,9,10,35,36). It is important to recognize, as heralded by Steriade and others (2,4,7,37,38), that understanding human epilepsy requires an appreciation of the science of seizure at the neural systems level, in addition to considering focal synaptic events.…”

Section: Discussionmentioning

confidence: 99%

Anterior Thalamic Mediation of Experimental Seizures: Selective EEG Spectral Coherence

Mirski

Tsai

Rossell³

et al. 2003

Epilepsia

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Summary:Purpose: Physiological evidence has shown that the anterior thalamus (AN) and its associated efferents/ afferents constitute an important propagation pathway for pentylenetetrazol (PTZ)-mediated generalized seizures in rodents. Previous work demonstrated metabolic, physical, chemical, and electrical stimulation data supporting a role for AN in the expression of PTZ seizures. We now extend these observations through examination of neuroelectric signal indicators during seizure epochs. We show that the EEG recorded from AN is highly coherent with surface cortical (CTX) EEG during the immediate preconvulsant period and during the ictal stateough.Methods: Awake rats were continuously infused with PTZ until clonic seizures were recorded by using both subcortical AN, posterior thalamus (PT), or hippocampal (HPC) bipolar electrodes and cortical EEG. Through the signal-analysis techniques of ordinary and partial coherence, it was possible to focus selectively on signal correlations between AN and CTX (AN/CTX) by removing the effects of unaffiliated regions such as PT and HPC.Results: Coherence of PT/CTX was observed to be modest, and partial coherence of PT/CTX with the effects of AN/CTX removed did not improve the signal coherence of PT/CTX (PT/ CTX-AN). In contrast, AN/CTX coherence was observed to be high, with undiminished correlation when PT/CTX influence was removed (AN/CTX-PT). The most robust band of AN/ CTX coherence was centered around the spike-wave clonic frequency of 1-3 Hz. Partial multiple coherence-analysis techniques were used to remove the possible signal contributions from hippocampus in addition to PT. The AN/CTX coherence remained fully preserved in the low-frequency bands.Conclusions: These data provide electrophysiologic evidence supporting the special role of the anterior thalamus in the propagation of seizure activity between subcortex and cortex. Key Words: Anterior thalamus-EEG-Coherence-Seizure-Pentylenetetrazol.The precise neuronal pathways underlying the propagation and generalization of epileptic seizure activity remain largely unknown (1-6). Numerous studies have been performed to analyze the electrophysiology of focal cortical and hippocampal epileptic foci, and the local spread of these electrical paroxysms (7-10). Identification of specific cortical-subcortical pathways mediating seizure propagation between deep and surface neuronal elements has yet remained elusive, despite studies supporting the contribution of deep brain regions in clinical and EEG seizure expression (1-6). Mapping such connectivity would greatly improve our understanding of seizure mechanisms on a systems level, and offer potential sites for target-specific therapy, such as deep brain stimulation.Previously we established that the thalamic anterior nuclear complex (AN), a thalamic element of the limbic system, is an important gating center for the propagation of pentylenetetrazol (PTZ) seizure activity (11-15). Experiments supporting the hypothesis of AN mediation of convulsive activity include selective up...

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“…Позднее D. Jinnai и соавт. [8] по-казали на животной модели повышение порога су-дорожной активности после деструкции мамилляр-ных тел.…”

Section: Discussionunclassified

Bilateral radiofrequency anterior thalamotomy in intractable epilepsy patients

Ситников¹,

Grigoryan²,

Mishnyakova³

2016

Vopr. neirokhir.

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Двусторонняя радиочастотная передняя таламотомия у пациентов с фармакорезистентной эпилепсией К.м.н. а.р. СИтНИКоВ, д.м.н., проф. Ю.а. ГрИГорЯН, к.м.н. л.п. МИшНЯКоВа ФГау «лечебно-реабилитационный центр» Минздрава россии, Москва, россия Актуальность. Выявление важной роли передних таламических ядер anterior Thalamic nuclei (aTn) в генерализации судо-рог привело к повышению интереса к хирургическим вмешательствам в этой области у пациентов с фармакорезистентной эпилепсией. Моделирование на животных показало высокую эффективность деструкций aTn в предупреждении развития и снижении частоты приступов. однако двусторонняя радиочастотная деструкция aTn у человека до сих пор не была описанa. Цель исследования -выполнить и оценить результаты двусторонней радиочастотной передней таламотомии у пациентов с фармакорезистентной эпилепсией. Материал и методы. Нами впервые была выполнена двусторонняя стереотаксическая радиочастотная термокоагуляция aTn 13 пациентам, длительно страдавшим фармакорезистентной эпилепсией. перед операцией определяли длительность заболевания, возраст начала приступов, локализацию источников патологической активности, тип приступов и морфоло-гические повреждения, а также оценивали проводимую фармакотерапию. Все вмешательства были осуществлены под местной анестезией и сопровождались интраоперационной микроэлектродной регистрацией нейрональной активности и записью электроэнцефалограммы (ЭЭГ). Результаты. оперированы 7 мужчин и 6 женщин в возрасте от 22 до 48 лет. у всех пациентов эпилептогенные очаги лока-лизовались в лобных и/или височных долях мозга. Мрт выявила эпилептогенные структурные аномалии у 3 пациентов. послеоперационных осложнений не было. при дальнейшем обследовании 5 пациентов отметили отсутствие приступов, у 6 -снижение частоты приступов составило более 70%, у 1 -50% и у 1 пациента не последовало ответа на проведенное вмешательство. Достигнутый эффект выражался не только в снижении частоты и тяжести приступов, но и в уменьшении доз принимаемых противосудорожных препаратов. ЭЭГ также подтвердила значительное улучшение у подавляющего большинства пациентов. Заключение. Наш опыт показывает, что двусторонняя радиочастотная передняя таламотомия является безопасным и эффективным методом контроля судорожных приступов у человека. Дальнейшие исследования позволят уточнить крите-рии отбора пациентов для хирургического лечения на основании клинических и ЭЭГ-данных. Background. Identification of the crucial role of the anterior thalamic nuclei (aTn) in the generalization of seizures led to increased interest in surgical interventions in this particular area in intractable epilepsy patients. Simulation of aTn destruction in animals demonstrated its high efficacy for both preventing the seizure development and reducing the seizure rate. however, bilateral radiofrequency destruction of the anterior thalamic nuclei in humans has not yet bee described. Objective. The study objective was to perform bilateral radiofrequency anterior thalamotomy in intractable epilepsy patients and to evaluate its results. ...

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Effect of brain-stem lesions on metrazol-induced seizures in cats

Cited by 41 publications

References 17 publications

Interruption of the connections of the mammillary bodies protects against generalized pentylenetetrazol seizures in guinea pigs

Interruption of the connections of the mammillary bodies protects against generalized pentylenetetrazol seizures in guinea pigs

Anterior Thalamic Mediation of Experimental Seizures: Selective EEG Spectral Coherence

Bilateral radiofrequency anterior thalamotomy in intractable epilepsy patients

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