The Impact of Perineuronal Net Digestion Using Chondroitinase ABC on the Intrinsic Physiology of Cortical Neurons.

Perineuronal nets (PNNs) are a form of aggregate Extracellular Matrix (ECM) in the brain. Recent evidence suggests that the postnatal deposition of PNNs may play an active role in regulating neuroplasticity and, potentially, neurological disorders. Observations of high levels of PNN expression around somas, proximal dendrites, and axon initial segments of a subtype of neurons have also led to proposals that PNNs may modulate the intrinsic properties of the neurons they ensheathe. While high levels of PNNs are postnatally expressed throughout the neocortex, it is still unclear how they impact the neuronal physiology of the many classes and subtypes of neurons that exist. In this study, we demonstrate that Chondroitinase ABC digestion of PNNs from acute cortical slices from juvenile mice (P28–35) resulted in neuron-specific impacts on intrinsic physiology. Fast spiking (FS) interneurons showed decreased input resistance, resting membrane potential (RMP), reduced action potential (AP) peaks and altered spontaneous synaptic inputs. Low-Threshold Spiking interneurons showed altered rebound depolarizations and decreased frequency of spontaneous synaptic inputs. Putative excitatory neurons; regular spiking, bursting, and doublet phenotypes did not demonstrate any alterations. Our data indicate that chABC-sensitive PNNs may specifically regulate the intrinsic and synaptic physiology of inhibitory interneurons. © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

神经元周围网络（PNNs）是大脑中一种聚集的细胞外基质（ECM）形式。近期证据表明，PNNs在出生后的沉积可能在调节神经可塑性以及潜在的神经疾病方面发挥积极作用。对神经元的一种亚型的胞体、近端树突和轴突起始段周围高水平的PNN表达的观察也导致有人提出，PNNs可能调节它们所包裹的神经元的内在特性。虽然高水平的PNNs在出生后在整个新皮质中都有表达，但它们如何影响存在的许多种类和亚型的神经元的神经生理学仍不清楚。在这项研究中，我们证明了用软骨素酶ABC对幼年小鼠（P28 - 35）急性皮质切片中的PNNs进行消化，会对内在生理学产生神经元特异性影响。快发放（FS）中间神经元表现出输入电阻降低、静息膜电位（RMP）降低、动作电位（AP）峰值降低以及自发突触输入改变。低阈值发放中间神经元表现出反弹去极化改变以及自发突触输入频率降低。假定的兴奋性神经元；规则发放、爆发式发放和双发放表型没有表现出任何改变。我们的数据表明，对软骨素酶ABC敏感的PNNs可能特异性地调节抑制性中间神经元的内在和突触生理学。© 2018国际脑研究组织。由爱思唯尔有限公司出版。保留所有权利。