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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1992-6-5
pubmed:abstractText
The rodent barrel field cortex integrates somatosensory information from two separate thalamic nuclei, the ventral posterior medial nucleus (VPM) and the rostral sector of the posterior complex (POm). This paper compares the sensory responses of POm and VPM cells in urethane-anesthetized rats as a first step in determining how cortex integrates multiple sensory pathways. A complete representation of the contralateral body surface was identified in POm. Trigeminal receptive fields (RFs) of POm and VPM cells were mapped by computer-controlled displacement of individual whiskers; responses were quantified by using peristimulus time histograms. Average RF size was similar in POm (5.1 whiskers) and VPM (4.4 whiskers), but evoked responses in the two nuclei differed significantly according to all other measures. VPM cells were maximally responsive to one single whisker--the "center RF." Stimulating this whisker evoked, on average, a response of 1.4 spikes/stimulus at a latency of 7 ms; surrounding whiskers evoked responses of less than 1 spike/stimulus at latencies of greater than 8 ms. In contrast, POm cells were nearly equally responsive to several whiskers. Quantitative criteria allowed us to designate a single whisker as the "center RF" and stimulating this whisker evoked, on average, a response of 0.5 spikes/stimulus at a latency of 19 ms. VPM cells, but not POm cells, were able to "follow" repeated whisker deflection at greater than 5 Hz. We conclude that, when a single whisker is deflected, VPM activates the related cortical barrel-column at short latency--before the onset of activity in POm. The timing of activation could allow POm cells to modulate the spread of activity between cortical columns.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9967
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
318
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
462-76
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Somatic sensory responses in the rostral sector of the posterior group (POm) and in the ventral posterior medial nucleus (VPM) of the rat thalamus.
pubmed:affiliation
Institute for Developmental Neuroscience, Vanderbilt University, Nashville, Tennessee 37203.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.