| Relative distribution of synapses in the pulvinar nucleus of the cat: implications regarding the "driver/modulator" theory of thalamic function. | |
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MedLine Citation:
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PMID: 12455011 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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To provide a quantitative comparison of the synaptic organization of "first-order" and "higher-order" thalamic nuclei, we followed bias-corrected sampling methods identical to a previous study of the cat dorsal lateral geniculate nucleus (dLGN; Van Horn et al. [2000] J. Comp. Neurol. 416:509-520) to examine the distribution of terminal types within the cat pulvinar nucleus. We observed the following distribution of synaptic contacts: large terminals that contain loosely packed round vesicles (RL profiles), 3.5%; presynaptic profiles that contain densely packed pleomorphic vesicles (F1 profiles), 7.3%; profiles that could be both presynaptic and postsynaptic that contain loosely packed pleomorphic vesicles (F2 profiles), 5.0%; and small terminals that contain densely packed round vesicles (RS profiles), 84.2%. Postembedding immunocytochemistry for gamma-aminobutyric acid (GABA) was used to distinguish the postsynaptic targets as thalamocortical cells or interneurons. The distribution of synaptic contacts on thalamocortical cells was as follows: RL profiles, 2.1%; F1 profiles, 6.9%; F2 profiles, 5.4%; and RS profiles, 85.6%. The distribution of synaptic contacts on interneurons was as follows: RL profiles, 11.8%; F1 profiles, 9.7%; F2 profiles, 2.8%; and RS profiles, 75.6%. These distributions are similar to that found within the dLGN in that the RS inputs (the presumed "modulators") far outnumber the RL inputs (the presumed "drivers"). However, in comparison to the dLGN, the pulvinar nucleus receives significantly fewer numbers of RL, F1, and F2 contacts and significantly higher numbers of RS contacts. Thus, the RS/RL synapse ratio in the pulvinar nucleus is 24:1, in contrast to the 5:1 RS/RL synapse ratio in the dLGN (Van Horn et al., 2000). In first-order nuclei, the lower RS/RL synapse ratio may result in the transfer of visual information that is largely unmodified. In contrast, in higher-order nuclei, the higher RS/RL synapse ratio may allow for a finer modulation of driving inputs. |
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Authors:
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Siting Wang; Michael A Eisenback; Martha E Bickford |
Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: The Journal of comparative neurology Volume: 454 ISSN: 0021-9967 ISO Abbreviation: J. Comp. Neurol. Publication Date: 2002 Dec |
Date Detail:
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Created Date: 2002-11-27 Completed Date: 2003-01-22 Revised Date: 2011-08-01 |
Medline Journal Info:
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Nlm Unique ID: 0406041 Medline TA: J Comp Neurol Country: United States |
Other Details:
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Languages: eng Pagination: 482-94 Citation Subset: IM |
Copyright Information:
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Copyright 2002 Wiley-Liss, Inc. |
Affiliation:
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Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, Kentucky 40292, USA. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Cats* Dendrites / ultrastructure Immunohistochemistry Microscopy, Electron Neural Pathways / anatomy & histology, cytology Presynaptic Terminals / ultrastructure Pulvinar / physiology, ultrastructure* Synapses / physiology, ultrastructure* Thalamus / physiology*, ultrasonography |
| Grant Support | |
ID/Acronym/Agency:
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NS35377/NS/NINDS NIH HHS; R01 NS035377-06A1/NS/NINDS NIH HHS; R29 NS035377-05/NS/NINDS NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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