Changes in somatosensory evoked potentials following an experimental focal ischaemic lesion in thalamus

A. Ladds, N. M. Branston, J. Vajda, J. E. McGillicuddy, L. Symon

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Experiments have been performed to produce localized thalamic ischaemia in baboons anaesthetised with alpha-chloralose. Somatosensory evoked potentials to median nerve stimulation were recorded in the medial lemniscus. VPL of thalamus and the primary somatosensory cortex. Local blood flow was also recorded by the hydrogen clearance technique in these regions. The early potential recorded in thalamus has been shown to be generated from 3 sources: (i) a positivity generated outside the VPL, (ii) local wavelets, most likely from synaptic activity close to the recording electrode, and (iii) a local overall negativity. The first of these potentials alone remains after thalamic ischaemia. It arises below the level of the thalamus, being very likely generated by the afferent volley in the medial lemniscus, and is seen in the surface-recorded response as the early component P8 (corresponding to P15 in the human).

Original languageEnglish
Pages (from-to)233-240
Number of pages8
JournalElectroencephalography and Clinical Neurophysiology/ Evoked Potentials
Volume71
Issue number3
DOIs
Publication statusPublished - Jan 1 1988

    Fingerprint

Keywords

  • Ischaemia
  • Somatosensory evoked potentials
  • Thalamus

ASJC Scopus subject areas

  • Neuroscience(all)
  • Clinical Neurology

Cite this