Linked Life Data

17101230

Source:http://linkedlifedata.com/resource/pubmed/id/17101230

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-12-12
pubmed:abstractText
Mammalian nociceptors have been classified into subclasses based on differential neurotrophin sensitivity and binding of the plant isolectin B4 (IB4). Most of the nerve growth factor-responsive IB4-negative (IB4 (-)) nociceptors contain neuropeptides such as substance P and calcitonin gene-related peptide, whereas the glial-derived neurotrophic factor-responsive IB4-positive (IB4 (+)) neurons predominantly lack such neuropeptides. We hypothesized that the differences in neuropeptide content between IB4 (+) and (-) neurons might be reflected in differences in stimulated exocytosis and/or endocytosis. To address this, we monitored the secretory activity of acutely dissociated neurons from adult rat trigeminal ganglia (TRG) using cell membrane capacitance (Cm) measurements and the fluorescent membrane-uptake marker N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino)phenyl)hexatrienyl)pyridinium dibromide (FM4-64). Cm measurements were performed under whole-cell voltage clamp and neurons were depolarized from -75 mV to +10 mV to elicit exocytosis. Both types of TRG neurons showed similarly-sized, calcium-dependent increases in Cm, demonstrating that both IB4 (+) and (-) TRG neurons are capable of stimulated exocytosis. However, the peak Cm of IB4 (+) neurons decayed faster toward baseline than that of IB4 (-) neurons. Also, IB4 (+) neurons had stable Cm responses to repeated stimuli whereas IB4 (-) neurons loss their secretory response during repeated stimulation. These data suggested that the IB4 (+) neurons possess a faster rate of endocytosis and vesicle replenishment than IB4 (-) neurons. To test this, we measured vesicle trafficking with the fluorescent membrane dye FM4-64. FM4-64 staining showed that IB4 (-) neurons exhibit a larger pool of endocytosed vesicles than IB4 (+) neurons because the peak fluorescence increases in IB4 (-) neurons were larger but slower than in IB4 (+) neurons. However, the recycled vesicles were released faster in IB4 (+) compared with IB4 (-) neurons. Taken together these data suggest that the IB4 (+) TRG neurons have faster exocytosis and endocytosis than the IB4 (-) neurons.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
144
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
665-74
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Two types of neurotransmitter release patterns in isolectin B4-positive and negative trigeminal ganglion neurons.
pubmed:affiliation
Division of Oral Biology and Medicine, UCLA School of Dentistry, 63-078 CHS, Los Angeles, CA 90095-1668, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural