Aging alters the multichemical networking profile of the human brain:: an in vivo 1H-MRS study of young versus middle-aged subjects
Aging alters the multichemical networking profile of the human brain:: an in vivo 1H-MRS study of young versus middle-aged subjects
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DOI：
10.1046/j.1471-4159.2001.t01-1-00238.x
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发表时间：
2001-04-01
影响因子：
4.7
通讯作者：
Apkarian, AV
中科院分区：
文献类型：
--
作者：
Grachev, ID;Swarnkar, A;Apkarian, AV
在我们最近对正常衰老的研究中，我们发现与使用体内质子磁共振波谱（H-1-MRS）的年轻受试者相比，中年受试者大脑中多种化学物质的浓度降低。我们假设，这些年龄依赖性的脑化学变化的差异可能是衰老过程中的多化学网络配置文件（MCNP）的变化的反映。使用H-1-MRS和相关性分析，我们研究了区域化学水平和MCNP的模式内和跨多个大脑区域的所有9种化学物质的H-1-MR光谱。本文比较了21例青年（19-31岁）和31例中年（40-52岁）正常志愿者的脑化学变化和MCNP模式。与年轻组相比，中年受试者的前额叶皮层和感觉运动皮层（SMC）的化学水平显着下降。其中，背外侧前额叶皮层（DLPFC）的神经递质GABA和谷氨酸的变化最大。我们还发现，随着年龄的增长，MCNP中的整体化学相关强度在所有研究的大脑区域内和之间显着增加。这些变化是由大脑区域的负化学连接模式的改变引起的，中年受试者的负化学连接变得更弱（不那么消极）。区域间化学连接扣带皮层，SMC和丘脑的变化最大，随着年龄的增长。在研究的大多数化学物质（包括神经递质GABA和谷氨酸）中，发现衰老过程中大脑区域的化学相关强度水平增加，而N-乙酰天冬氨酸则没有。这些与年龄相关的神经递质连接差异不依赖于区域。结果表明，衰老与局部脑化学和脑MCNP的变化有关。后一个过程可能反映了一种适应性或补偿性反应（可能与随着年龄的增长树突的伸长有关），以减少区域脑化学物质的水平。本文提出的H-1-MRS方法可以作为一种有价值的工具，在正常和异常老化的脑化学，MCNP及其关系的研究。
In our most recent study of normal aging, we found decreased concentration of multiple chemicals in the brain of middle-aged subjects, as compared with younger subjects using in vivo proton magnetic resonance spectroscopy (H-1-MRS). We hypothesized that these age-dependent differences in brain chemistry changes might be a reflection of the multichemical-networking-profile (MCNP) changes during aging. Using H-1-MRS and correlation analysis, we examined the patterns of regional chemical levels and MCNP within and across multiple brain regions for all nine chemicals of H-1-MR spectra. The brain chemistry changes and MCNP patterns were compared between 21 young (19-31-year-old) and 31 middle-aged (40-52-year-old) normal volunteers. Middle-aged subjects demonstrated a significant decrease of chemical levels in the prefrontal cortex and sensorimotor cortex (SMC), as compared with the young age group. Of these, neurotransmitters GABA and glutamate in the dorsolateral prefrontal cortex (DLPFC) were altered the most. We also found a significant increase of overall chemical correlation strength in MCNP within and across all studied brain regions with increased age. These changes were caused by alterations in the pattern of negative chemical connectivity across brain regions, which become weaker (less negative) in middle-aged subjects. The interregional chemical connectivity for the cingulate cortex, SMC and the thalamus was changed the most with increased age. Increased levels of chemical correlation strength across brain regions in aging were found for most chemicals studied (including neurotransmitters GABA and glutamate), and not for N-acetyl aspartate. These age-related differences in the connectivity of neurotransmitters were not region dependent. The results suggest that aging is associated with changes of the regional brain chemistry and the brain MCNP. The latter process may reflect an adaptive or compensatory response (possibly related to the elongation of dendrites with aging) to reduced levels of regional brain chemicals. The H-1-MRS approach proposed here can be used as a valuable tool in the study of the brain chemistry, MCNP and their relationships in normal and abnormal aging.