Journal article
The corpus callosum modulates spindle-burst activity within homotopic regions of somatosensory cortex in newborn rats
The European journal of neuroscience, Vol.28(8), pp.1457-1466
10/2008
DOI: 10.1111/j.1460-9568.2008.06461.x
PMCID: PMC2669778
PMID: 18973571
Abstract
The corpus callosum, a major interhemispheric fiber tract, mediates communication between homotopic regions within the primary somatosensory cortex (S1). Recently, in 1- to 6-day-old rats, brief bursts of oscillatory activity - called spindle-bursts (SBs) - were described in cortical somatosensory areas following sensory feedback from sleep-related myoclonic twitches or specific peripheral stimulation. To determine whether interhemispheric communication via the corpus callosum modulates the expression of SBs during this early period of development, we investigated the spontaneous expression of SBs in unanesthetized 1- to 6-day-old rats as well as SBs evoked by plantar surface stimulation of the forepaw. We hypothesized that surgically disrupting transcallosal communication (i.e. with callosotomy) or unilateral pharmacological manipulation of S1 activity (e.g. by blocking muscarinic receptors) would alter S1 activity in one or both hemispheres. First, callosotomy doubled the rate of spontaneous, twitch-related SBs in left and right S1s by reducing the interval between successive SBs. Second, unilateral infusion into the left S1 of the muscarinic receptor antagonist, scopolamine, inhibited SBs in response to right forepaw stimulation; importantly, SBs were now disinhibited in the right S1 to right forepaw stimulation, thus 'unmasking' an ipsilateral representation. Subsequent callosotomy reinstated contralateral SB responses in the left S1. Finally, tactile and proprioceptive stimulation produced dissociable neurophysiological S1 responses; specifically, SBs were produced in response to proprioceptive, but not tactile, stimulation. We conclude that the corpus callosum modulates functionally inhibitory interactions between homotopic regions in left and right S1s during the early developmental period when organized neurophysiological activity is first detected in the neocortex.
Details
- Title: Subtitle
- The corpus callosum modulates spindle-burst activity within homotopic regions of somatosensory cortex in newborn rats
- Creators
- Amy Jo Marcano-Reik - Department of Psychology, University of Iowa, Iowa City, IA 52242, USAMark S Blumberg
- Resource Type
- Journal article
- Publication Details
- The European journal of neuroscience, Vol.28(8), pp.1457-1466
- DOI
- 10.1111/j.1460-9568.2008.06461.x
- PMID
- 18973571
- PMCID
- PMC2669778
- NLM abbreviation
- Eur J Neurosci
- ISSN
- 0953-816X
- eISSN
- 1460-9568
- Publisher
- France
- Grant note
- MH50701 / NIMH NIH HHS MH66424 / NIMH NIH HHS R29 MH050701 / NIMH NIH HHS R01 MH050701-13 / NIMH NIH HHS R29 MH050701-05 / NIMH NIH HHS K02 MH066424-07 / NIMH NIH HHS R01 MH050701 / NIMH NIH HHS K02 MH066424 / NIMH NIH HHS
- Language
- English
- Date published
- 10/2008
- Academic Unit
- Psychological and Brain Sciences; Iowa Neuroscience Institute; Biology
- Record Identifier
- 9984002478502771
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