Linked Life Data

2175855

Source:http://linkedlifedata.com/resource/pubmed/id/2175855

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-2-1
pubmed:abstractText
Ventromedial hypothalamic projections to the midbrain central gray may be involved in the mediation of female reproductive behavior. In order to demonstrate and examine projections of the ventromedial nucleus in the midbrain central gray, in the rat, electrolytic lesions were placed in the ventromedial nucleus and the midbrain central gray was examined for ultrastructural signs of degeneration at various intervals, i.e. 27.5 h and two, four, six and eight days following the lesions. The fine structure of the midbrain central gray of unlesioned animals was also examined to characterize its normal morphology and to establish a baseline with which to compare the effects of the lesion. In unlesioned animals, the neuropil of midbrain central gray contained several synaptic types, with axodendritic synapses appearing to be the most predominant. Dendrites contained well-preserved microtubules. Synaptic endings contained many clear, round vesicles and some contained dense-cored vesicles as well. Neuropil synapses were both asymmetric and symmetric. Cell bodies were characterized by light cytoplasm and had asymmetric and symmetric synapses on their surface. Following electrolytic lesions in the ventromedial nucleus, various types of degenerative patterns were seen in the midbrain central gray, including electron-dense, flocculent, watery, and pinocytotic degeneration. Specific characteristics of degeneration included shrunken, dense axons and endings, clumped synaptic vesicles, abnormally large, dark mitochondria, membranous sacs of various sizes, swollen endings with reduced numbers of synaptic vesicles, and endings and processes containing large numbers of coated vesicles. Some of these signs were already evident at 27.5 h following the lesion. In addition, degenerating postsynaptic processes and cell bodies were seen in the midbrain central gray. At 27.5 h survival time, degenerating dendritic processes often appeared swollen, devoid of microtubules, and contained enlarged mitochondria. At longer survival times neuronal degeneration was observed in the midbrain central gray, characterized by electron-dense cell bodies and pycnotic nuclei. Both degenerating pre- and postsynaptic elements appeared to be engulfed by glial processes. Control lesions in non-hypothalamic regions which project to the midbrain central gray, i.e. nucleus gigantocellularis and pontine reticular formation and in a non-projecting region, i.e. parietal cortex, were performed.(ABSTRACT TRUNCATED AT 400 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
395-407
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Projections of ventromedial hypothalamic neurons to the midbrain central gray: an ultrastructural study.
pubmed:affiliation
Department of Anatomy, University of Illinois, Chicago 60612.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.