Sivaramakrishnan Shobhana, Lynch William P
Department of Otolaryngology, Sensory Neuroscience Research Center, West Virginia University School of Medicine, Morgantown, WV 26506, USA.
Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH 44272, USA.
J Clin Cell Immunol. 2017 Apr;8(2). doi: 10.4172/2155-9899.1000492. Epub 2017 Mar 13.
Neural networks play a critical role in establishing constraints on excitability in the central nervous system. Several recent studies have suggested that network dysfunction in the brain and spinal cord are compromised following insult by a neurodegenerative trigger and might precede eventual neuronal loss and neurological impairment. Early intervention of network excitability and plasticity might therefore be critical in resetting hyperexcitability and preventing later neuronal damage. Here, the behavior of neurons that generate burst firing upon recovery from inhibitory input or intrinsic membrane hyperpolarization (rebound neurons) is examined in the context of neural networks that underlie rhythmic activity observed in areas of the brain and spinal cord that are vulnerable to neurodegeneration. In a non-inflammatory rodent model of spongiform neurodegenerative disease triggered by retrovirus infection of glia, rebound neurons are particularly vulnerable to neurodegeneration, likely due to an inherently low calcium buffering capacity. The dysfunction of rebound neurons translates into a dysfunction of rhythmic neural circuits, compromising normal neurological function and leading to eventual morbidity. Understanding how virus infection of glia can mediate dysfunction of rebound neurons, induce hyperexcitability and loss of rhythmic function, pathologic features observed in neurodegenerative disorders ranging from epilepsy to motor neuron disease, might therefore suggest a common pathway for early therapeutic intervention.
神经网络在建立对中枢神经系统兴奋性的限制方面发挥着关键作用。最近的几项研究表明,在受到神经退行性触发因素的损伤后,大脑和脊髓中的网络功能会受损,并且可能先于最终的神经元丢失和神经功能障碍出现。因此,早期干预网络兴奋性和可塑性对于重置过度兴奋性和预防后期神经元损伤可能至关重要。在此,我们在神经网络的背景下研究了在从抑制性输入或内在膜超极化恢复时产生爆发性放电的神经元(反弹神经元)的行为,这些神经网络是在大脑和脊髓中易发生神经退行性变的区域观察到的节律性活动的基础。在由胶质细胞的逆转录病毒感染引发的海绵状神经退行性疾病的非炎症性啮齿动物模型中,反弹神经元特别容易发生神经退行性变,这可能是由于其固有的低钙缓冲能力。反弹神经元的功能障碍转化为节律性神经回路的功能障碍,损害正常神经功能并导致最终发病。了解胶质细胞的病毒感染如何介导反弹神经元的功能障碍、诱导过度兴奋性和节律性功能丧失,这些是从癫痫到运动神经元疾病等神经退行性疾病中观察到的病理特征,因此可能提示早期治疗干预的共同途径。