Nelson R J, Kaas J H
J Comp Neurol. 1981 Jun 10;199(1):29-64. doi: 10.1002/cne.901990104.
The somatotopic pattern of the connections of the ventroposterior nucleus of the thalamus with the representations of the body surface in somatic cortical Areas 3b and 1 were investigated in macaque monkeys using the anatomical tracers horseradish peroxidase (HRP), and 3H-proline. These tracers, in combination or separately, were injected into one or more cortical sites, after the skin surface capable of activating neurons at each site had been defined with microelectrode mapping methods. These injection sites were later related to the overall organizations of the two cutaneous representations as determined in more extensive mapping experiments (Nelson et al, '80). Finally, zones of anterograde and retrograde label in the thalamus were located with reference to architectonically defined subnuclei in the ventroposterior nucleus (VP). The results led to the following conclusions. (1) Zones of cells in VP projecting to a given location in either Area 3b or 1 also receive reciprocal projections from the cortical target. (2) A given cortical location typically relates to a disc-shaped or lamellar region in VP with the disc extending rostrocaudally and dorsoventrally, being most narrow in the mediolateral dimension. (3) The representations of the same body surface in Area 1 and Area 3b relate to the same region of VP. However, since fewer cells were generally labeled after Area 1 injections, less dense terminations are suggested from VP to Area 1 than to Area 3b. (4) VP is the major or exclusive relay of somatosensory information to the two cutaneous representations from the thalamus. Labeled neurons or zones of terminations were found outside VP in other parts of the somatosensory thalamus only when injection sites extended into cortex outside Areas 3b and 1. (5) The face, hand, limbs, and foot are represented in a mediolateral sequence of subnuclei within VP. A dorsal capping subnucleus is apparently largely devoted to the axial trunk and perhaps other hairy skin surfaces such as some parts of the proximal surfaces of the limbs. (6) While anterior and posterior surfaces of the hind limb are widely separated by the glabrous foot in the cortical representations, they appear to be represented in adjacent zones in the thalamus.
利用解剖示踪剂辣根过氧化物酶（HRP）和³H-脯氨酸，在猕猴中研究了丘脑腹后核与躯体皮层3b区和1区体表代表区之间连接的躯体定位模式。在用微电极图谱法确定了能够激活每个部位神经元的皮肤表面后，将这些示踪剂单独或联合注入一个或多个皮层部位。这些注射部位随后与在更广泛的图谱实验（Nelson等人，1980年）中确定的两种皮肤代表区的整体组织相关联。最后，参照丘脑腹后核（VP）中根据结构定义的亚核，确定丘脑内顺行和逆行标记的区域。结果得出以下结论。（1）投射到3b区或1区给定位置的VP中的细胞区也接受来自皮层靶区的反向投射。（2）给定的皮层位置通常与VP中的盘状或层状区域相关，该盘在前后方向和背腹方向延伸，在内外侧维度上最窄。（3）1区和3b区中同一体表的代表区与VP的同一区域相关。然而，由于1区注射后通常标记的细胞较少，提示从VP到1区的终末比到3b区的密度更低。（4）VP是丘脑向这两个皮肤代表区传递躯体感觉信息的主要或唯一中继站。仅当注射部位延伸到3b区和1区以外的皮层时，才在躯体感觉丘脑的其他部位的VP以外发现标记神经元或终末区。（5）面部、手部、四肢和足部在VP内的亚核中按内外侧顺序排列。一个背侧覆盖亚核显然主要负责轴干，也许还负责其他有毛皮肤表面，如四肢近端表面的某些部位。（6）虽然在皮层代表区中，后肢的前后表面被无毛的足部广泛分隔，但它们在丘脑中似乎由相邻区域代表。
