Nucleus reticularis thalami and neocortical paroxysms in the rat
| Autor: | Roberto Giglio, Mauro Mancia, Gabriella Marini, G. Macchi |
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| Rok vydání: | 1995 |
| Předmět: |
Time Factors
Models Neurological Alpha (ethology) Corpus Callosum Rats Sprague-Dawley Epilepsy Cortex (anatomy) medicine Animals business.industry General Neuroscience Brain Electroencephalography medicine.disease Sleep in non-human animals Nucleus reticularis thalami Rats medicine.anatomical_structure Disinhibition Thalamic Nuclei Reticular connective tissue medicine.symptom business Neuroscience Nucleus |
| Zdroj: | The European journal of neuroscience. 7(11) |
| ISSN: | 0953-816X |
| Popis: | The role of the nucleus reticularis thalami in spike-wave discharges in rats with genetic absence epilepsy has already been demonstrated. This study further investigated the role of the nucleus reticularis thalami in paroxysmal synchronizations in Sprague-Dawley rats; this strain shows no propensity to epileptic activity. Electroencephalographic patterns were followed in chronically implanted, unrestrained rats. After both electrolytic and chemical unilateral lesions, stereotaxically placed in the anterolateral sectors of this nucleus (verified post mortem), abnormal electroencephalographic rhythms (high-voltage polyspikes and spike-wave complexes) were recorded from the frontoparietal cortex, primarily in the contralateral hemisphere. Stereotyped discharges at 3 Hz developed progressively from multiple spikes within the alpha frequency range through the lengthening of the wave component. The excessive synchronized activity recorded from the intact hemisphere was of greater amplitude and occurred slightly earlier than from the lesioned hemisphere. These EEG patterns were associated with behavioural manifestations closely resembling those seen during absence seizures in humans. Bilateral lesions did not induce paroxysmal activity, both hemispheres being characterized by dominant delta/theta activity without signs of EEG-synchronized sleep. The seizures may thus have been due to disinhibition of the contralateral reticularis nucleus, recently shown to project to the reticularis nucleus of the other side in rats. This working hypothesis is supported by callosal cuts. The results indicate that the reticular neurons exert a control over neocortical paroxysmal activity even in animals which do not present genetic absence epilepsy. |
| Databáze: | OpenAIRE |
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