Expression of presenilin 1 and synapse-related proteins during postnatal development is not different between accelerated senescence-prone and -resistant mice.
SAMP1TA/Ngs is an inbred strain of senescence-accelerated mice in which there is delayed development of cognitive functions and dendritic spine formation compared with normal control SAMR1TA//Ngs mice. It is hypothesized that abnormalities might be in the postnatal expression of synapse-related proteins in SAMP1TA/Ngs mice. Quantitative western blot analyses showed that the postnatal developmental changes in the expression of synaptophysin, post-synaptic density protein 95 and presenilin 1 in the cerebrum were similar between SAMP1TA/Ngs and SAMR1TA//Ngs mice. Therefore, the expression of synapse-related proteins was not disturbed in SAMP1TA/ Ngs mice regardless of reported abnormal numbers of dendritic spines during postnatal development. Immunohistochemical studies showed that the expression of synaptophysin in the neuropil increased postnatally with development in the same way in SAMP1TA/Ngs and SAMR1TA//Ngs mice. Presenilin 1 expression was relatively high at age 5 days in the neuropil of the cerebral cortex and decreased with postnatal development in the same way in SAMP1TA/Ngs and SAMR1TA//Ngs mice. At age 5 days the distribution of presenilin 1 was similar to the distribution of synaptophysin in that there were two separate immunoreactive patterns: a subpial band and patches in the middle layers reminiscent of barrels. These findings suggest that presenilin 1 is transiently expressed in the neuropil to induce synaptogenesis, and then its expression decreases overall.
Department of Pathology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan.
Hiromi
H
Keino
Masao
M
Kishikawa
Mamoru
M
Satoh
Atsuyoshi
A
Shimada
D000375:Aging / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000096:biosynthesis*; D051379:Mice; D008815:Mice, Inbred Strains; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D019581:Neuropil / Q000378:metabolism; D053764:Presenilin-1; D016708:Synaptophysin / Q000096:biosynthesis*; D013687:Telencephalon / Q000254:growth & development* / Q000378:metabolism
D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D053764:Presenilin-1; D016708:Synaptophysin; C033652:postsynaptic density proteins