Cell Physiology and Pharmacology, University of Leicester, UK.
Aging Cell. 2011 Jun;10(3):392-402. doi: 10.1111/j.1474-9726.2011.00682.x. Epub 2011 Mar 22.
Cortical astrocytes express fast ionotropic receptors for glutamate and ATP, although their role in neurone-glia communication remains controversial. Stimulation of neuronal afferents in mice neocortex triggers complex glial synaptic currents (GSCs) mediated by NMDA, P2X and AMPA receptors and glutamate transporters. In addition, astrocytes demonstrate spontaneous 'miniature' GSCs resulting from quantal release of neurotransmitters. Here, we demonstrate that maturation and aging of the brain of mice (from 1 to 21 months) affect the density of ionotropic receptors in astrocytes and their role in GSCs generation. The AMPA-receptor-mediated component is the largest in young animals and progressively declines with age. The P2X and NMDA components of GSC are smallest in young, maximal in adult (3 and 6 months old) and once more decrease in old mice, probably reflecting the remodelling of neuronal-glial circuitry. Our results demonstrate that fast synaptic transmission between neurones and astrocytes in neocortex that may be involved in information processing in neuronal-glial networks undergoes remodelling during brain maturation and aging.
皮质星形细胞表达快速离子型谷氨酸盐和 ATP 受体，尽管它们在神经元-胶质细胞通讯中的作用仍存在争议。在小鼠新皮层中刺激神经元传入会触发由 NMDA、P2X 和 AMPA 受体和谷氨酸转运体介导的复杂胶质突触电流 (GSCs)。此外，星形细胞表现出自发的“微小”GSCs，这是由于神经递质的量子释放引起的。在这里，我们证明了小鼠大脑的成熟和衰老（从 1 个月到 21 个月）会影响星形细胞中离子型受体的密度及其在 GSCs 产生中的作用。AMPA 受体介导的成分在年轻动物中最大，并随着年龄的增长逐渐下降。GSC 的 P2X 和 NMDA 成分在年轻动物中最小，在成年动物（3 个月和 6 个月大）中最大，在老年动物中再次减少，这可能反映了神经元-胶质回路的重塑。我们的结果表明，可能参与神经元-胶质网络中信息处理的新皮层中神经元和星形细胞之间的快速突触传递在大脑成熟和衰老过程中会发生重塑。
