Linked Life Data

9236216

Source:http://linkedlifedata.com/resource/pubmed/id/9236216

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
1997-8-28
pubmed:abstractText
The effects of galanin (GAL) on magnocellular neurosecretory cells (MNCs) were examined during microelectrode recordings from supraoptic neurons in superfused hypothalamic explants. Application of the full-length peptide (GAL1-29) or of the N-terminal fragment GAL1-16 produced reversible membrane hyperpolarization with an IC50 near 10 nM. These effects were associated with an increase of membrane conductance, with a reversal potential near -70 mV, and were not blocked by tetrodotoxin, indicating that the receptors mediating these effects are located postsynaptically. Hyperpolarizing responses were also observed in response to the GAL-like chimeric ligands M35 and M40, suggesting that these behave as partial agonists at galanin receptors. The reversal potential of the GAL-mediated effect was unaffected by reducing extracellular chloride or by intracellular chloride injection, indicating that the effects of galanin are not mediated by modulation of chloride conductances. In contrast, reducing the external concentration of potassium ions from 3 to 1 mM shifted the reversal potential of the responses to -85 mV, suggesting the involvement of a potassium conductance. When tested on spontaneously active MNCs, the hyperpolarizing effects of galanin were associated with a suppression of firing in both continuously active and phasically active neurons. Inhibition of phasic bursts was mediated both through the inhibitory effects of the hyperpolarization and through a GAL-mediated inhibition of the depolarizing afterpotential that is responsible for the production of individual bursts. These results suggest that galanin may be a potent endogenous modulator of firing pattern in hypothalamic neuroendocrine cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0270-6474
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6048-56
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Galanin inhibits continuous and phasic firing in rat hypothalamic magnocellular neurosecretory cells.
pubmed:affiliation
Centre for Research in Neuroscience, Montreal General Hospital Research Institute and McGill University, Montreal, Quebec, Canada H3G 1A3.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't