Chuhma Nao, Rayport Stephen
Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, United States.
Department of Psychiatry, Columbia University, New York, NY, United States.
Front Cell Neurosci. 2024 Jul 31;18:1412897. doi: 10.3389/fncel.2024.1412897. eCollection 2024.
The cytoarchitecture of the striatum is remarkably homogeneous, in contrast to the regional variation in striatal functions. Whether differences in the intrinsic membrane properties of striatal neurons contribute to regional heterogeneity has not been addressed systematically. We made recordings throughout the young adult mouse striatum under identical conditions, with synaptic input blocked, from four major striatal neuron types, namely, the two subtypes of spiny projection neurons (SPNs), cholinergic interneurons (ChIs), and fast-spiking GABAergic interneurons (FSIs), sampling at least 100 cells per cell type. Regional variation manifested across all cell types. All cell types in the nucleus accumbens (NAc) shell had higher input impedance and increased excitability. Cells in the NAc core were differentiated from the caudate-putamen (CPu) for both SPN subtypes by smaller action potentials and increased excitability. Similarity between the two SPN subtypes showed regional variation, differing more in the NAc than in the CPu. So, in the Str, both the intrinsic properties of interneurons and projection neurons are regionally heterogeneous, with the greatest difference between the NAc and CPu; greater excitability of NAc shell neurons may make the region more susceptible to activity-dependent plasticity.
与纹状体功能的区域差异形成对比的是，纹状体的细胞结构非常均匀。纹状体神经元内在膜特性的差异是否导致区域异质性尚未得到系统研究。我们在相同条件下，对成年小鼠整个纹状体进行记录，阻断突触输入，记录了四种主要的纹状体神经元类型，即棘状投射神经元（SPN）的两种亚型、胆碱能中间神经元（ChI）和快速放电的γ-氨基丁酸能中间神经元（FSI），每种细胞类型至少采样100个细胞。所有细胞类型均表现出区域差异。伏隔核（NAc）壳中的所有细胞类型都具有更高的输入阻抗和更高的兴奋性。对于两种SPN亚型，NAc核心中的细胞与尾状核-壳核（CPu）中的细胞不同，其动作电位较小且兴奋性增加。两种SPN亚型之间的相似性表现出区域差异，在NAc中比在CPu中差异更大。因此，在纹状体中，中间神经元和投射神经元的内在特性在区域上都是异质的，NAc和CPu之间差异最大；NAc壳神经元更高的兴奋性可能使该区域更容易受到活动依赖性可塑性的影响。
