Linked Life Data

9870597

Source:http://linkedlifedata.com/resource/pubmed/id/9870597

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1999-3-11
pubmed:abstractText
Trigeminal sensory afferents from the eyelids convey two types of information that are important for the blink reflex. Movement of the lashes activates low-threshold mechanoreceptors which evoke protective blinks. Information about eyelid position is also transmitted centrally and is used to adapt the metrics of the blink reflex to changing conditions over time. This study employed transganglionic transport of horseradish peroxidase conjugated to choleratoxin-B subunit or wheat-germ agglutinin to investigate trigeminal afferents supplying the eyelids of macaque monkeys. Ganglion cells labeled from upper- and lower-lid injections were located in the ophthalmic and maxillary portions of the trigeminal ganglion, respectively. In both cases, labeled terminals were observed ipsilateral to the injected eyelid in the principal and spinal trigeminal nuclei. However, only a few labeled terminals were present in the principal nucleus, and very sparse terminal labeling was confined to a few locations along the ventral border of the pars oralis and interpolaris of the spinal trigeminal nucleus. The main concentration of label was found in the pars caudalis at and immediately below the spinomedullary junction. The terminal field from the upper eyelid was located ventrally in the pars caudalis, and that from the lower eyelid was located more dorsally. In both cases, the labeled terminal field was densest within lamina II of the spinal trigeminal nucleus. The heavy concentration of eyelid central terminals at the spinomedullary junction is surprising in light of physiological studies indicating representation of all parts of the face throughout the trigeminal nucleus. The distribution of eyelid afferent terminals in the macaque is caudal to the main concentration of corneal afferent terminals at the pars interpolaris/caudalis border. This may be a basis for differences seen in blinks produced by corneal as opposed to supraorbital stimulation. The presence of a single major site of eyelid primary afferent terminals suggests that sensory input for both eyelid proprioception and blink-reflex activation passes through this segment of the spinal trigeminal nucleus. These results provide a basis for investigation of the central connections of pars caudalis neurons in order to better establish the pathways producing trigeminally evoked blinks and blink adaptation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0014-4819
pubmed:author
pubmed:issnType
Print
pubmed:volume
123
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
368-81
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
The distribution of primary afferent terminals from the eyelids of macaque monkeys.
pubmed:affiliation
Department of Anatomy, University of Mississippi Medical Center, Jackson 39216, USA. pjm@anat.umsmed.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't