Linked Life Data

6203612

Source:http://linkedlifedata.com/resource/pubmed/id/6203612

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1984-8-20
pubmed:abstractText
The glabrous skin of the hindlimb of the cat contains 3 types of low-threshold mechanoreceptors: Pacinian corpuscles (PC), and slowly and rapidly adapting receptors. In the present study, 12 primary afferent fibers transmitting impulses from PC were injected intra-axonally with horseradish peroxidase (HRP) in the spinal cord to examine the morphology of their terminals in the dorsal horn. At the light microscopic level, terminal arborizations were observed in laminae II-VI of the dorsal horn, extending up to 7 mm rostrocaudally in and near the seventh lumbar segment. Bouton-like swellings, predominantly (67%) of the en passant type, were distributed in two discrete clusters, one concentrated rostrally in Rexed's laminae III-IV, and the other concentrated caudally in lamina V. At the electron microscopic level, a combination of morphometric and serial reconstructive analyses with 3 fibers revealed the following. Boutons labelled with HRP invariably contained clear round vesicles, approximately 40 nm in diameter. Labelled bouton sections had longest dimensions of 1.84 +/- 0.63 micron. Their shapes varied from rounded to elongated forms with occasional scalloped appearances. A majority (73%) of the contacts associated with HRP-filled boutons were made with dendritic spines and shafts. Thick postsynaptic densities were usually associated with these synapses, although thinner densities were also observed. 24% of the contacts made by labelled boutons were synapse-like contacts with unlabelled vesicle-containing structures. The vesicles in the unlabelled structures were usually pleomorphic, but sometimes round. These contacts were identified as 'synapse-like' because labelling obscured possible landmarks necessary for definitive identification of synapses. However, in most of these contacts, there was an accumulation of vesicles near the cleft on the unlabelled side, suggesting that the labelled boutons were postsynaptic. Only 3% of the contacts made by labelled boutons were axosomatic. The lengths of contacts with dendritic spines (0.49 +/- 0.23 micron) or with dendrites proper (0.45 +/- 0.20 micron) were significantly longer than those with vesicle-containing unlabelled structures (0.31 +/- 0.18 micron). The portions of cross-sectional bouton contours devoted to synaptic or synapse-like contacts accounted for 9-13% of the perimeters. The larger the bouton, the longer the summed lengths of contacts. Serial reconstruction of selected labelled boutons revealed both simple and quite complex synaptic organizations, including glomeruli with labelled boutons as the central component.(ABSTRACT TRUNCATED AT 400 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-8993
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
302
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
135-50
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Ultrastructure of pacinian corpuscle primary afferent terminals in the cat spinal cord.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.