Principles of Intrinsic Motor Cortex Connectivity in Primates
Principles of Intrinsic Motor Cortex Connectivity in Primates
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DOI：
10.1523/jneurosci.0003-20.2020
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发表时间：
2020-05-27
影响因子：
5.3
通讯作者：
Gharbawie, Omar A.
中科院分区：
文献类型：
--
作者：
Card, Nicholas S.;Gharbawie, Omar A.
前肢在运动皮层的表征是现代神经科学中的一个重要模型系统。努力了解组织的MI前肢代表猴子集中在输入和输出。相比之下，内在的MI连接仍然大多未被探索，这是令人惊讶的，因为区域内连接普遍超过外在连接。为了解决这一知识差距，我们首先映射了MI前肢代表与皮质内微刺激（ICMS）在雄性松鼠猴。接下来，我们用ICMS +内在信号光学成像（ISOI）确定了单个MI部位的连通性。每个刺激部位激活了一个独特的模式的补丁（类似于0.25至1.0毫米半径），我们量化的运动地图。手臂部位激活了主要位于手臂区域的贴片。手网站遵循同样的原则，但程度较轻。结果表明，功能匹配的补丁之间的优先连接是一个突出的组织原则，MI。给定站点的连接模式在一系列电流幅度、脉冲串持续时间、脉冲频率和微电极深度中保持不变。此外，我们发现，在躯体感觉皮层之间的连接，我们揭示了与ICMS +ISOI和连接已知的示踪剂密切对应。因此，ICMS+ISOI是一种有效的工具，用于映射皮质连接，特别是有利于采样大量的网站。这一特点是有助于揭示内在MI连接的空间特异性，这似乎是编织成前肢代表的躯体位置组织。这样一个框架调用了感觉皮层区域的模块化组织。
The forelimb representation in motor cortex (MI) is an important model system in contemporary neuroscience. Efforts to understand the organization of the MI forelimb representation in monkeys have focused on inputs and outputs. In contrast, intrinsic MI connections remain mostly unexplored, which is surprising given that intra-areal connections universally outnumber extrinsic connections. To address this knowledge gap, we first mapped the MI forelimb representation with intracortical microstimulation (ICMS) in male squirrel monkeys. Next, we determined the connectivity of individual MI sites with ICMS + intrinsic signal optical imaging (ISOI). Every stimulation site activated a distinctive pattern of patches (similar to 0.25 to 1.0 mm radius) that we quantified in relation to the motor map. Arm sites activated patches that were mostly in arm zones. Hand sites followed the same principle, but to a lesser extent. The results collectively indicate that preferential connectivity between functionally matched patches is a prominent organizational principle in MI. Connectivity patterns for a given site were conserved across a range of current amplitudes, train durations, pulse frequencies, and microelectrode depths. In addition, we found close correspondence in somatosensory cortex between connectivity that we revealed with ICMS +ISOI and connections known from tracers. ICMS+ISOI is therefore an effective tool for mapping cortical connectivity and is particularly advantageous for sampling large numbers of sites. This feature was instrumental in revealing the spatial specificity of intrinsic MI connections, which appear to be woven into the somatotopic organization of the forelimb representation. Such a framework invokes the modular organization well-established for sensory cortical areas.