Matches in SemOpenAlex for { <https://semopenalex.org/work/W2080472389> ?p ?o ?g. }
Showing items 1 to 95 of
95
with 100 items per page.
- W2080472389 endingPage "504" @default.
- W2080472389 startingPage "491" @default.
- W2080472389 abstract "The primary visual cortex of the tree shrew is characterized by the lack of ocular dominance columns. The two eyes are represented in sublayers of laminae 3 and 4. In an earlier study using the transneuronal transport we observed that the geniculate afferents from the two eyes do not initially overlap and then segregate into their appropriate sublaminae. The final distribution pattern can already be observed during the early postnatal period. Since segregation and elimination of afferent terminal branches do not seem to take place, we wanted to investigate whether or not an overproduction of synapses can be observed as in several other animals. We examined layers 3B, 3C, 4A, and 4B, which receive afferents from the retina via the lateral geniculate nucleus, from P5 to maturity by using the electron microscope. The brain tissue was excised in the region where the central vision is represented in adult animals. Then we determined the density of synapses per 100 μm2 neuropil for each of the four sublayers at the ages P5, P15, P19, P23, P31, and P42 and in the adult animal (AD). In determining the neuropil we measured the size of two additional compartments, i.e., the compartments consisting of perikarya and of blood vessels. At a higher resolution we determined the fraction of Gray type I and type II synapses in each sublamina and in each developmental stage. The size of the neuropil increases from 57% at P5 to 81% in AD whereas the compartment of perikarya decreases from 42% to 15% and the compartment of blood vessels increases from 1.3% to 3.9%. The synaptic density starts with very low values (3.5/100 μm2) at P5. Then it increases rapidly and attains a maximal rate of increase during the period of eyelid opening. After this period the increase is slowed down and approaches the adult value (12.5/100 μm2) slowly. An overproduction of synapses could not be observed. The percentage of type I and type II synapses also changes during this period. The fraction of type I synapses amounts to 73% at P5 and increases to 92% in AD. The increase intensity of type I synapses is continuous and does not show any sign of overproduction. The density of type II synapses rapidly reaches its final value and then remains constant. Possibly there is a slight overproduction during the period of eyelid opening. The fact that an overproduction of synapses could not be observed may be related to the specific pattern of ingrowth of geniculate afferents which seem to go to their appropriate laminae without any detectable sign of segregation." @default.
- W2080472389 created "2016-06-24" @default.
- W2080472389 creator A5015856706 @default.
- W2080472389 creator A5080143631 @default.
- W2080472389 creator A5089245851 @default.
- W2080472389 date "1991-06-15" @default.
- W2080472389 modified "2023-10-17" @default.
- W2080472389 title "Synaptogenesis in the primary visual cortex of the tree shrew (Tupaia belangeri)" @default.
- W2080472389 cites W1560129441 @default.
- W2080472389 cites W1853003442 @default.
- W2080472389 cites W1970519355 @default.
- W2080472389 cites W1974447763 @default.
- W2080472389 cites W1986411584 @default.
- W2080472389 cites W1987377201 @default.
- W2080472389 cites W1990689634 @default.
- W2080472389 cites W1991837273 @default.
- W2080472389 cites W2003052675 @default.
- W2080472389 cites W2003238158 @default.
- W2080472389 cites W2015282923 @default.
- W2080472389 cites W2020204296 @default.
- W2080472389 cites W2024614800 @default.
- W2080472389 cites W2024648781 @default.
- W2080472389 cites W2032774015 @default.
- W2080472389 cites W2035319691 @default.
- W2080472389 cites W2036740507 @default.
- W2080472389 cites W2043384694 @default.
- W2080472389 cites W2053120614 @default.
- W2080472389 cites W2053373257 @default.
- W2080472389 cites W2056671825 @default.
- W2080472389 cites W2058582588 @default.
- W2080472389 cites W2072378554 @default.
- W2080472389 cites W2082922514 @default.
- W2080472389 cites W2093377164 @default.
- W2080472389 cites W2094024657 @default.
- W2080472389 cites W2125346623 @default.
- W2080472389 cites W2155562064 @default.
- W2080472389 cites W2157061030 @default.
- W2080472389 cites W2158649743 @default.
- W2080472389 cites W2166348429 @default.
- W2080472389 cites W2506421807 @default.
- W2080472389 cites W4213416533 @default.
- W2080472389 cites W819181521 @default.
- W2080472389 cites W937409197 @default.
- W2080472389 doi "https://doi.org/10.1002/cne.903080313" @default.
- W2080472389 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/1865013" @default.
- W2080472389 hasPublicationYear "1991" @default.
- W2080472389 type Work @default.
- W2080472389 sameAs 2080472389 @default.
- W2080472389 citedByCount "17" @default.
- W2080472389 crossrefType "journal-article" @default.
- W2080472389 hasAuthorship W2080472389A5015856706 @default.
- W2080472389 hasAuthorship W2080472389A5080143631 @default.
- W2080472389 hasAuthorship W2080472389A5089245851 @default.
- W2080472389 hasConcept C105702510 @default.
- W2080472389 hasConcept C131074121 @default.
- W2080472389 hasConcept C169760540 @default.
- W2080472389 hasConcept C2775969318 @default.
- W2080472389 hasConcept C2776362945 @default.
- W2080472389 hasConcept C2777831001 @default.
- W2080472389 hasConcept C2779345533 @default.
- W2080472389 hasConcept C529278444 @default.
- W2080472389 hasConcept C6084040 @default.
- W2080472389 hasConcept C86803240 @default.
- W2080472389 hasConceptScore W2080472389C105702510 @default.
- W2080472389 hasConceptScore W2080472389C131074121 @default.
- W2080472389 hasConceptScore W2080472389C169760540 @default.
- W2080472389 hasConceptScore W2080472389C2775969318 @default.
- W2080472389 hasConceptScore W2080472389C2776362945 @default.
- W2080472389 hasConceptScore W2080472389C2777831001 @default.
- W2080472389 hasConceptScore W2080472389C2779345533 @default.
- W2080472389 hasConceptScore W2080472389C529278444 @default.
- W2080472389 hasConceptScore W2080472389C6084040 @default.
- W2080472389 hasConceptScore W2080472389C86803240 @default.
- W2080472389 hasIssue "3" @default.
- W2080472389 hasLocation W20804723891 @default.
- W2080472389 hasLocation W20804723892 @default.
- W2080472389 hasOpenAccess W2080472389 @default.
- W2080472389 hasPrimaryLocation W20804723891 @default.
- W2080472389 hasRelatedWork W129490072 @default.
- W2080472389 hasRelatedWork W1549461546 @default.
- W2080472389 hasRelatedWork W1978195348 @default.
- W2080472389 hasRelatedWork W2062212387 @default.
- W2080472389 hasRelatedWork W2080472389 @default.
- W2080472389 hasRelatedWork W2133602791 @default.
- W2080472389 hasRelatedWork W2141895876 @default.
- W2080472389 hasRelatedWork W2522310008 @default.
- W2080472389 hasRelatedWork W2766063118 @default.
- W2080472389 hasRelatedWork W4248273761 @default.
- W2080472389 hasVolume "308" @default.
- W2080472389 isParatext "false" @default.
- W2080472389 isRetracted "false" @default.
- W2080472389 magId "2080472389" @default.
- W2080472389 workType "article" @default.