Rapoport S I, London E D, Takei H
Exp Brain Res. 1982;Suppl 5:86-101. doi: 10.1007/978-3-642-68507-1_12.
In cerebral cortical regions of the conscious Fischer-344 rat, regional cerebral blood flow (rCBF) as measured with 14C-indoantipyrine, and the cerebral metabolic rate for O2(CMRO2) do not decline after 3 months of age. On the other hand, the regional cerebral metabolic rate for glucose (rCMRglc) as measured with 14C-2-deoxy-D-glucose, falls significantly in some but not all cerebral cortical regions after 3 months. More generally, rCBF and rCMRglc do not follow identical courses during development and aging of the rat brain, although they remain stoichiometrically coupled among specific regions at any given age. Between 1 and 3 months, both increase in most brain regions, but after 3 months of age rCMRglc tends to fall throughout the brain, whereas rCBF tends to rise or remain unchanged in cerebral cortical regions, and falls after 12 months in posterior brain regions. The courses of rCBF, rCMRglc and CMRO2 during development and aging of the rat brain indicate that (a) stoichiometric coupling between flow and metabolism is maintained between 1 and 34 months of age, (b) the calculated coupling relation between rCBF and rCMRglc changes with age, possibly because rCBF increasingly sensitive to metabolism or because "constants" are employed to calculate rCMRglc or rCBF change with aging, and (c) cerebral cortical oxidative metabolism does not generally decline after 1 year of age. This constantly suggests that plasticity responses in the cerebral cortex of the rat compensate for senescence-associated morphological and neurochemical defects so as to preserve resting cortical functional activity.
在清醒的Fischer-344大鼠的大脑皮质区域，用14C-异碘安替比林测量的局部脑血流量（rCBF）以及脑氧代谢率（CMRO2）在3个月龄后不会下降。另一方面，用14C-2-脱氧-D-葡萄糖测量的局部脑葡萄糖代谢率（rCMRglc）在3个月后，在部分而非全部大脑皮质区域显著下降。更普遍地说，在大鼠脑发育和衰老过程中，rCBF和rCMRglc的变化过程并不相同，尽管在任何给定年龄，它们在特定区域之间仍保持化学计量耦合。在1至3个月之间，大多数脑区的两者均增加，但3个月龄后，rCMRglc在全脑趋于下降，而rCBF在大脑皮质区域趋于上升或保持不变，在后脑区域12个月后下降。大鼠脑发育和衰老过程中rCBF、rCMRglc和CMRO2的变化过程表明：（a）在1至34个月龄之间，血流与代谢之间的化学计量耦合得以维持；（b）计算得出的rCBF与rCMRglc之间的耦合关系随年龄变化，可能是因为rCBF对代谢越来越敏感，或者是因为用于计算rCMRglc或rCBF随衰老变化的“常数”发生了改变；（c）1岁后大脑皮质氧化代谢通常不会下降。这一直表明，大鼠大脑皮质中的可塑性反应可补偿与衰老相关的形态和神经化学缺陷，从而维持静息皮质功能活动。
