Department of Zoology, Michigan State University, East Lansing, MI 48824-1115, USA.
BMC Neurosci. 2010 Oct 25;11:140. doi: 10.1186/1471-2202-11-140.
As we age, the speed of axonal regeneration declines. At the biophysical level, why this occurs is not well understood.
To investigate we first measured the rate of axonal elongation of sensory neurons cultured from neonatal and adult rats. We found that neonatal axons grew 40% faster than adult axons (11.5 µm/hour vs. 8.2 µm/hour). To determine how the mechanical properties of axons change during maturation, we used force calibrated towing needles to measure the viscosity (stiffness) and strength of substrate adhesion of neonatal and adult sensory axons. We found no significant difference in the strength of adhesions, but did find that adult axons were 3 times intrinsically stiffer than neonatal axons.
Taken together, our results suggest decreasing axonal stiffness may be part of an effective strategy to accelerate the regeneration of axons in the adult peripheral nervous system.
随着年龄的增长，轴突的再生速度会下降。从生物物理的角度来看，其具体原因尚不清楚。
为了进行研究，我们首先测量了从新生和成年大鼠培养的感觉神经元的轴突伸长速度。我们发现，新生大鼠的轴突比成年大鼠的轴突生长速度快 40%（11.5 µm/hour 比 8.2 µm/hour）。为了确定轴突在成熟过程中力学特性如何变化，我们使用力校准牵引针来测量新生和成年感觉轴突的粘性（硬度）和基底黏附强度。我们发现黏附强度没有显著差异，但确实发现成年轴突的固有硬度比新生轴突硬 3 倍。
综上所述，我们的结果表明，降低轴突硬度可能是加速成年周围神经系统轴突再生的有效策略的一部分。
