Maia Pedro D, Kutz J Nathan
Department of Applied Mathematics, University of Washington, Seattle, WA, 98195-3925, USA.
J Comput Neurosci. 2017 Jun;42(3):323-347. doi: 10.1007/s10827-017-0643-y. Epub 2017 Apr 10.
The presence of diffuse Focal Axonal Swellings (FAS) is a hallmark cellular feature in many neurological diseases and traumatic brain injury. Among other things, the FAS have a significant impact on spike-train encodings that propagate through the affected neurons, leading to compromised signal processing on a neuronal network level. This work merges, for the first time, three fields of study: (i) signal processing in excitatory-inhibitory (EI) networks of neurons via population codes, (ii) decision-making theory driven by the production of evidence from stimulus, and (iii) compromised spike-train propagation through FAS. As such, we demonstrate a mathematical architecture capable of characterizing compromised decision-making driven by cellular mechanisms. The computational model also leads to several novel predictions and diagnostics for understanding injury level and cognitive deficits, including a key finding that decision-making reaction times, rather than accuracy, are indicative of network level damage. The results have a number of translational implications, including that the level of network damage can be characterized by the reaction times in simple cognitive and motor tests.
弥漫性局灶性轴突肿胀（FAS）的存在是许多神经系统疾病和创伤性脑损伤的标志性细胞特征。除其他因素外，FAS对通过受影响神经元传播的脉冲序列编码有重大影响，导致神经网络层面的信号处理受损。这项工作首次融合了三个研究领域：（i）通过群体编码在神经元的兴奋性-抑制性（EI）网络中进行信号处理，（ii）由刺激产生的证据驱动的决策理论，以及（iii）通过FAS受损的脉冲序列传播。因此，我们展示了一种能够表征由细胞机制驱动的受损决策的数学架构。该计算模型还产生了一些用于理解损伤程度和认知缺陷的新颖预测和诊断方法，包括一个关键发现，即决策反应时间而非准确性表明网络层面的损伤。这些结果具有许多转化意义，包括网络损伤程度可以通过简单认知和运动测试中的反应时间来表征。
