An evoked potential mapping of transcallosal projections in the cat

In ten adult cats anesthetized with ketamine hydrochloride the neocortex was exposed and rectangular pulses (1msec, 0.5 Hz and variable intensity) were applied to discrete points of one side and transcallosal evoked potentials were recorded from the other. The stimulation and recording positions wer...

Full description

Saved in:
Bibliographic Details
Main Authors: A. Cukiert, C. Timo-Iaria
Format: Article
Language:English
Published: Thieme Revinter Publicações 1989-03-01
Series:Arquivos de Neuro-Psiquiatria
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1989000100001&lng=en&tlng=en
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850257249056849920
author A. Cukiert
C. Timo-Iaria
author_facet A. Cukiert
C. Timo-Iaria
author_sort A. Cukiert
collection DOAJ
description In ten adult cats anesthetized with ketamine hydrochloride the neocortex was exposed and rectangular pulses (1msec, 0.5 Hz and variable intensity) were applied to discrete points of one side and transcallosal evoked potentials were recorded from the other. The stimulation and recording positions were determined on a cartesian map of most of the exposable neocortical areas and the potentials were analysed as to their components, voltage and latency. Passive spread and electrotonic potentials and the effects of increasing frequency were also analysed. The results showed large transcallosal potentials in some areas and an increase of potentials in the caudorostral direction, attaining the highest values in anteromedial areas of the suprasylvian gyrus. Confirming anatomical studies, a few silent spots were found in the motor and somesthetic cortex and in restricted posterior regions of the visual cortex, where small or zero voltages occurred. While causing weak contralateral potentials, stimulation of some posterior sites provoked high voltage potentials in anterior regions of the side being stimulated and in the corresponding area of the opposite site. These posterior sites are. poorly interconnected by the corpus callosum. The L-shaped indirect connection described in this work may be involved in some types of epilepsy and may explain the effectiveness of partial callosotomy in their treatment.
format Article
id doaj-art-53350cff64d74ac6b3f5bc2fc7ad2169
institution OA Journals
issn 1678-4227
language English
publishDate 1989-03-01
publisher Thieme Revinter Publicações
record_format Article
series Arquivos de Neuro-Psiquiatria
spelling doaj-art-53350cff64d74ac6b3f5bc2fc7ad21692025-08-20T01:56:28ZengThieme Revinter PublicaçõesArquivos de Neuro-Psiquiatria1678-42271989-03-014711710.1590/S0004-282X1989000100001S0004-282X1989000100001An evoked potential mapping of transcallosal projections in the catA. Cukiert0C. Timo-Iaria1Universidade de São PauloUniversidade de São PauloIn ten adult cats anesthetized with ketamine hydrochloride the neocortex was exposed and rectangular pulses (1msec, 0.5 Hz and variable intensity) were applied to discrete points of one side and transcallosal evoked potentials were recorded from the other. The stimulation and recording positions were determined on a cartesian map of most of the exposable neocortical areas and the potentials were analysed as to their components, voltage and latency. Passive spread and electrotonic potentials and the effects of increasing frequency were also analysed. The results showed large transcallosal potentials in some areas and an increase of potentials in the caudorostral direction, attaining the highest values in anteromedial areas of the suprasylvian gyrus. Confirming anatomical studies, a few silent spots were found in the motor and somesthetic cortex and in restricted posterior regions of the visual cortex, where small or zero voltages occurred. While causing weak contralateral potentials, stimulation of some posterior sites provoked high voltage potentials in anterior regions of the side being stimulated and in the corresponding area of the opposite site. These posterior sites are. poorly interconnected by the corpus callosum. The L-shaped indirect connection described in this work may be involved in some types of epilepsy and may explain the effectiveness of partial callosotomy in their treatment.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1989000100001&lng=en&tlng=en
spellingShingle A. Cukiert
C. Timo-Iaria
An evoked potential mapping of transcallosal projections in the cat
Arquivos de Neuro-Psiquiatria
title An evoked potential mapping of transcallosal projections in the cat
title_full An evoked potential mapping of transcallosal projections in the cat
title_fullStr An evoked potential mapping of transcallosal projections in the cat
title_full_unstemmed An evoked potential mapping of transcallosal projections in the cat
title_short An evoked potential mapping of transcallosal projections in the cat
title_sort evoked potential mapping of transcallosal projections in the cat
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X1989000100001&lng=en&tlng=en
work_keys_str_mv AT acukiert anevokedpotentialmappingoftranscallosalprojectionsinthecat
AT ctimoiaria anevokedpotentialmappingoftranscallosalprojectionsinthecat
AT acukiert evokedpotentialmappingoftranscallosalprojectionsinthecat
AT ctimoiaria evokedpotentialmappingoftranscallosalprojectionsinthecat