Linked Life Data

11600628

Source:http://linkedlifedata.com/resource/pubmed/id/11600628

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2001-10-15
pubmed:abstractText
Zinc and copper are highly concentrated in several mammalian brain regions, including the olfactory bulb and hippocampus. Whole cell electrophysiological recordings were made from rat olfactory bulb neurons in primary culture to compare the effects of zinc and copper on synaptic transmission and voltage-gated ion channels. Application of either zinc or copper eliminated GABA-mediated spontaneous inhibitory postsynaptic potentials. However, in contrast to the similarity of their effects on inhibitory transmission, spontaneous glutamate-mediated excitatory synaptic activity was completely blocked by copper but only inhibited by zinc. Among voltage-gated ion channels, zinc or copper inhibited TTX-sensitive sodium channels and delayed rectifier-type potassium channels but did not prevent the firing of evoked single action potentials or dramatically alter their kinetics. Zinc and copper had distinct effects on transient A-type potassium currents. Whereas copper only inhibited the A-type current, zinc modulation of A-type currents resulted in either potentiation or inhibition of the current depending on the membrane potential. The effects of zinc and copper on potassium channels likely underlie their effects on repetitive firing in response to long-duration step depolarizations. Copper reduced repetitive firing independent of the initial membrane voltage. In contrast, whereas zinc reduced repetitive firing at membrane potentials associated with zinc-mediated enhancement of the A-type current (-50 mV), in a significant proportion of neurons, zinc increased repetitive firing at membrane potentials associated with zinc-mediated inhibition of the A-type current (-90 mV). Application of zinc or copper also inhibited voltage-gated Ca(2+) channels, suggesting a possible role for presynaptic modulation of neurotransmitter release. Despite similarities between the effects of zinc and copper on some ligand- and voltage-gated ion channels, these data suggest that their net effects likely contribute to differential modulation of neuronal excitability.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-3077
pubmed:author
pubmed:issnType
Print
pubmed:volume
86
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1652-60
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Zinc and copper influence excitability of rat olfactory bulb neurons by multiple mechanisms.
pubmed:affiliation
Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4340, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.