Abstract:
:Sensitization of defensive gill and siphon withdrawal reflexes in Aplysia results, in part, from presynaptic facilitation of transmitter release from mechanoreceptor sensory neurons that innervate the siphon skin and synapse with interneurons and motor neurons. Presynaptic facilitation also can be elicited by application of serotonin. This facilitation is associated with two phenomena, a prolongation of the presynaptic action potential resulting from a decrease in a specific K+ current and an enhancement of the Ca2+ transients elicited by depolarization. Previous work has shown that prolongation of the action potential enhances synaptic transmission at normal levels of release. Here we report that an additional set of processes also contributes to facilitation. When repeated activation of the sensory neurons induces profound homosynaptic depression, prolonging the duration of action potentials (or of depolarizing commands under voltage clamp) has little effect on transmitter release. Nonetheless, serotonin is still capable of enhancing release. Since homosynaptic depression underlies the behavioral process of habituation, the second set of processes, by counteracting the consequences of the depression, seems to mediate the effects of dishabituation in the sensory neuron. Prolongation of the action potential by closure of the K+ channel seems to mediate the effects of sensitization.
journal_name
Proc Natl Acad Sci U S Aauthors
Hochner B,Klein M,Schacher S,Kandel ERdoi
10.1073/pnas.83.22.8794subject
Has Abstractpub_date
1986-11-01 00:00:00pages
8794-8issue
22eissn
0027-8424issn
1091-6490journal_volume
83pub_type
杂志文章abstract::Apis mellifera originated in Africa and extended its range into Eurasia in two or more ancient expansions. In 1956, honey bees of African origin were introduced into South America, their descendents admixing with previously introduced European bees, giving rise to the highly invasive and economically devastating "Afri...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2008-03-04 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1984-09-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1988-05-01 00:00:00
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更新日期:2008-07-01 00:00:00
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更新日期:1980-03-01 00:00:00
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更新日期:2006-01-10 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1987-11-01 00:00:00
abstract::The feeling of being observed or merely participating in an experiment can affect individuals' behavior. Referred to as the Hawthorne effect, this inconsistently observed phenomenon can both provide insight into individuals' behavior and confound the interpretation of experimental manipulations. Here, we pursue both t...
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更新日期:2013-09-17 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1991-06-15 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2009-02-03 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2010-11-30 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1978-04-01 00:00:00
abstract::A fundamental aspect of climate change is the potential shifts in flowering phenology and pollen initiation associated with milder winters and warmer seasonal air temperature. Earlier floral anthesis has been suggested, in turn, to have a role in human disease by increasing time of exposure to pollen that causes aller...
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更新日期:2011-03-08 00:00:00
abstract::The objective of this study was to determine whether the vascular smooth muscle contractile effect of NG-methyl-L-arginine (NMA) is endothelium dependent and attributed to a decline in smooth muscle levels of cyclic GMP. Vascular smooth muscle levels of cyclic GMP are severalfold greater in endothelium-intact than in ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2000-05-23 00:00:00
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更新日期:2008-10-14 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2008-05-13 00:00:00