Expression of protein kinase-C substrate mRNA in the motor cortex of adult and infant macaque monkeys.Higo N, Oishi T, Yamashita A, Murata Y, Matsuda K, Hayashi M To understand the molecular and cellular bases of plasticity in the primate motor cortex,
we investigated the expression of three protein kinase-C (PKC) substrates: GAP-43,
myristoylated alanine-rich C-kinase substrate (MARCKS), and neurogranin, which are key
molecules regulating synaptic plasticity. Prominent signals for the threemRNAswere primarily
observed in pyramidal cells. Large pyramidal cells in layer V, fromwhich the descendingmotor
tract originates, contained weaker hybridization signals for GAP-43 and neurogranin mRNAs
than did the smaller pyramidal cells. We also performed double-label in situ hybridization
showing that GAP-43 and neurograninmRNAs were expressed in a subset of MARCKS-positive
neurons. Quantitative analysis showed that the expression was different between the layers:
layer VI contained the strongest and layer II the weakest signals for all three mRNAs. The
expression levels of GAP-43 and MARCKS mRNA in layer V were higher than in layer III, while
the expression level of neurogranin mRNA in layer V was almost the same as in layer III.
Developmental analysis from the newborn to adult indicated that the expression levels of the
three mRNAs were higher in the infant motor cortex than in the adult. The expression of both
GAP-43 and neurogranin mRNAs transiently increased over several months postnatally. The
present study showed that the expression of the three PKC substrates was specific to cell types,
cortical layers, and postnatal developmental stage. The specific expression may reflect
functional specialization for plasticity in the motor cortex of both infants and adults. Brain Research, 1171, 30–41, 2007 可塑性に関わる酵素プロテインキナーゼCの基質であるGAP-43, MARCKS, ニューログラニンのmRNAの発現を成熟期と発達期のマカクの運動野で調べた。成熟期には、どのmRNAも特に錐体細胞で強い発現が見られた。ただし、GAP-43とニューログラニンは、小型の錐体細胞に比べ、皮質脊髄路の起始細胞であるV層の大型錐体細胞での発現が弱かった。GAP-43とニューログラニンはMARCKSを発現している細胞の一部で発現していた。どのmRNAも浅層よりも深層で発現が強かった。どのmRNAも出生直後の方が成熟期よりも発現量が多かったが、GAP-43とニューログラニンに関しては一過性に増加してから減少した。これら三種のプロテインキナーゼ基質は細胞腫によって異なった発現制御を受けていることがわかった。
この研究は、産総研、日本大学との共同研究である。 NOV/19/2007
Copyright(C) 2007 PRI (web@pri.kyoto-u.ac.jp).
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