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Microelectrode recording of cerebellar and cerebral unit activity during convulsive afterdischarge

1962; Elsevier BV; Volume: 6; Issue: 1 Linguagem: Inglês

10.1016/0014-4886(62)90014-6

1090-2430

Augusto Fernández‐Guardiola, E Manni, Jacob Hayes Wilson, Robert S. Dow,

Neonatal and fetal brain pathology

Cerebellar unitary discharge has been recorded with microelectrodes from cerebellar cortex and nuclei before, during, and after different convulsive patterns induced in curarized rats by electrical stimulation of the brain, by intraperitoneal injection of convulsant drugs (Megimide or Metrazol), and by anoxia. It has been compared simultaneously with the electrical activity of the cerebral cortex (sensorimotor area) recorded either with microelectrodes or with concentric electrodes. Low-voltage, single or repetitive stimulation of sensorimotor area are incapable of modifying the cerebellar unitary discharge. They show an increase in frequency only after strong single shocks or repetitive cerebral stimulation. During anoxia the cerebral units show an acceleration after a short latency and afterwards they become silent. The cerebellar units also show an increase in frequency of discharge but they usually continue to be active even when the cerebrum is silent. After injection of convulsant drugs, such as Megimide and Metrazol, the cerebellar units exhibit first an acceleration of discharge at a time when the electrical activity of the brain is still normal. At a significantly later time the rate of discharge of cerebral units also increases. In some cases each high-voltage slow wave of the cerebral cortex is accompanied by an increase in the frequency of discharge of the cerebellar units. During the clonic period of the convulsive activity the cerebellar units are depressed but they begin to discharge again after the end of the seizure when the cerebral units are totally silent. The cerebellum may actively inhibit cerebral seizure activity.