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S C Suzuki

Publications and source records attributed to S C Suzuki.

4 recordsLinked to original sources
PubMed2000

Loss of cadherin-11 adhesion receptor enhances plastic changes in hippocampal synapses and modifies behavioral responses.

Cadherins organize symmetrical junctions between the pre- and postsynaptic membranes in central synapses. One of them, cadherin-11 (cad11), is expressed in the limbic system of the brain, most strongly in the hippocampus. Immunohistochemical studies of the hippocampus showed that cad11 proteins were densely distributed in its synaptic neuropil zones; in cultured hippocampal neurons, their distribution often overlapped with that of synaptophysin, and also occasionally with that of GluR1 at spines. To assess the role of cad11 in synaptic formation and/or function, we analyzed brains of cad11-deficient mice. In these mice, long-term potentiation (LTP) in the CA1 region of the hippocampus was, unexpectedly, enhanced; and the level of LTP saturation was increased. In behavioral tests, the mutant mice showed reduced fear- or anxiety-related responses. These results suggest that the cad11-mediated junctions may modulate synaptic efficacy, confining its dynamic changes to a limited range, or these junctions are required for normal development of synaptic organization in the hippocampus.

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PubMed1998

Cadherin-6 in the developing mouse brain: expression along restricted connection systems and synaptic localization suggest a potential role in neuronal circuitry.

Multiple subtypes of the cadherin homophilic cell-cell adhesion molecule are expressed differentially in developing and mature brains, each being expressed in restricted neuronal groups. Cadherin-6 (cad6) is one of such cadherins. Recent studies of cad6 mRNA expression in the postnatal mouse forebrain showed that it occurs in neurons constituting a specific subset of thalamocortical connections. Here we analyzed the localization of cad6 mRNA as well as its protein in the entire central nervous system and also in cranial ganglia of mice at late embryonic to postnatal stages. Our results showed that cad6 is expressed by a limited population of neurons or their precursors, which are synaptically connected to one another, throughout the perinatal stages, and that this expression delineates restricted neuronal circuits from the central to peripheral nervous systems, which include subpathways of the auditory, somatosensory, solitary, vestibular, and olivocerebellar systems. cad6 proteins were detected in these cad6 mRNA-positive neurons on the surface of their cell bodies or dendrites as well as in the cytoplasm. Confocal microscopic analysis revealed that the cad6 protein distribution overlapped that of synaptotagmin in synapse forming areas, suggesting that homotypic cad6 interactions are involved in synaptic connections between neurons expressing this protein. These findings support the idea that cadherin-mediated cell-cell adhesions take part in specific interneuronal connections.

Age Factors↗
PubMed1997

Neuronal circuits are subdivided by differential expression of type-II classic cadherins in postnatal mouse brains.

A number of type-II classic cadherin cell-cell adhesion molecules are expressed in the brain. To investigate their roles in brain morphogenesis, we selected three type-II cadherins, cadherin-6 (cad6), -8 (cad8) and -11 (cad11), and mapped their expressions in the forebrain and other restricted regions of postnatal mouse brains. In the cerebral cortex, each cortical area previously defined was delineated by a specific combinatorial expression of these cadherins. The thalamus and other subcortical regions of the forebrain were also subdivided by differential expression of the three cadherins; e.g., the medial geniculate body expressed only cad6; the ventral posterior thalamic nucleus, cad6/cad11; and the anteroventral thalamic nucleus, cad6/cad8. Likewise, in the olivocerebellar system, each subdivision of the inferior olive expressed a unique set of the three cadherins, and the cerebellar cortex had parasagittal stripes of cad8/cad11 expressions. Close analysis of these cadherin expression patterns revealed that they are correlated with neuronal connection patterns. Examples of these correlations include that cad6 delineates the auditory projection system, cad6/cad8/ cad11 are expressed by part of the Papez circuit, and cad6/cad8 are expressed by subdivisions of the olivo-nuclear circuit. Together with the recent finding that the cadherin adhesion system is localized in synaptic junctions, our findings support the notion that cadherin-mediated cell-cell adhesion plays a role in selective interneuronal connections during neural network formation.

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