Forelimb force direction and magnitude independently controlled by spinal modules in the macaque

腕の自由自在な動きをつくりだす多機能な神経細胞群の発見 --運動の方向と大きさを同時にコントロールする神経メカニズムの解明--. 京都大学プレスリリース. 2020-10-14.Primates aren't quite frogs. 京都大学プレスリリース. 2020-10-19.Modular organization of the spinal motor system is thought to reduce the cognitive complexity of simultaneously controlling the large number of muscles and joints in the human body. Although modular organization has been confirmed in the hindlimb control system of several animal species, it has yet to be established in the forelimb motor system or in primates. Expanding upon experiments originally performed in the frog lumbar spinal cord, we examined whether costimulation of two sites in the macaque monkey cervical spinal cord results in motor activity that is a simple linear sum of the responses evoked by stimulating each site individually. Similar to previous observations in the frog and rodent hindlimb, our analysis revealed that in most cases (77% of all pairs) the directions of the force fields elicited by costimulation were highly similar to those predicted by the simple linear sum of those elicited by stimulating each site individually. A comparable simple summation of electromyography (EMG) output, especially in the proximal muscles, suggested that this linear summation of force field direction was produced by a spinal neural mechanism whereby the forelimb motor output recruited by costimulation was also summed linearly. We further found that the force field magnitudes exhibited supralinear (amplified) summation, which was also observed in the EMG output of distal forelimb muscles, implying a novel feature of primate forelimb control. Overall, our observations support the idea that complex movements in the primate forelimb control system are made possible by flexibly combined spinal motor modules

Two-Color Analysis of Epidermal Cell Suspension of Mouse with Anti-DNP and Anti-Thy-1 Antibodies after Skin Painting with DNCB

The epidermal cell suspensions prepared from DNCB painted ear skin of C3H/He mice were double-stained for Thy-1 protein and DNP groups. The cells with both Thy-1 alloantigen and DNP groups in the specimen treated with anti-DNP and followed by anti-Thy-1,2 incubation were detected more frequently than the cells treated with the antibodies in the reverse order. This suggests that DNCB is coupled in vivo to the Thy-1 alloantigen on the surface of Thy-1 positive cells

The Effect of Tape Stripping on the Fate of Intradermally Injected Dinitrophenylated Isogeneic Epidermal Cells and Allogeneic Epidermal Cells in Guinea Pigs

DNP-iso ECs or alio ECs were injected intradermally into normal or tape stripped ear skin of inbred JY-1 strain guinea pigs. The fate of the injected cells was histologically examined. The cells proliferated in the dermis, formed EC nests with central keratinization and then elicited a reject reaction associated with necrosis of the epidermal structures in both normal and stripped skin. The suppressive effect of the tape stripping treatment on the reaction was not observed. The significance of the findings is discussed

Antigen Specificity of Retest Reaction in Contact Sensitivity

Guinea pigs doubly sensitized to 2,4-dinitrochlorobenzene (DNCB) and oxazolone (OX) were tested with DNCB, OX and croton oil and retested by epicutaneous application of DNCB and OX at the sites of prior contact reaction at the various intervals following skin testing. Antigen specificity of retest reaction to DNCB was demonstrated when retest of DNCB was performed 21 and 28 days after the skin testing. The significance of the findings is discussed

Ultrastructural Localization of DNP Groups on Draining Lymph Node Cells of Guinea Pigs Following Skin Painting with DNCB : II. Immunoferritin Electron Microscopic Study

The distribution of DNP groups on the cells taken from the draining lymph nodes of guinea pigs 12 hours after painting the skin with DNCB was examined by transmission immunoelectron microscopy using the antibody against DNP groups and ferritin as visual marker. The study showed that DNP groups were distributed on the surface of lymphocytes, both T and B cells, and macrophages. It is suggested that DNCB penetrates through skin into lymphatics carrying lymph from the painted site and combines with the membrane of lymphocytes and macrophages in the peripheral lymphoid system and that the resulting modified cells act as immunogens or tolerogens in contact sensitivity