科學(xué)家發(fā)現(xiàn)，在經(jīng)過雙手移植之后,，左手比右手更快地與大腦建立了聯(lián)系。此前的研究表明和手的控制有關(guān)的大腦區(qū)域與負責(zé)手臂以及面部肌肉的皮層區(qū)域相鄰,。這些大腦區(qū)域在一只手或雙手被切斷之后會進行相當(dāng)多的重新連接,，而面部和手臂的運動皮層代表區(qū)可能蔓延到原來被手支配的區(qū)域。
Angela Sirigu及其同事利用經(jīng)顱磁刺激方法監(jiān)視了兩個雙手移植受試者（最初慣用右手）手臂和手的肌肉電脈沖,。經(jīng)顱磁刺激是一種用脈沖磁場刺激皮層神經(jīng)元的方法,。這組科學(xué)家證明了恢復(fù)的進程對于一個人的左手和右手并不相同。根據(jù)受試者的大腦活動測定,，左手在手術(shù)后10個月重新獲得了顯著的存在,，而右手用了26個月，而且需要對大腦更強的刺激才能發(fā)現(xiàn),。這組作者說,，這些結(jié)果提示移植患者可以重新激活他們的雙手在運動皮層上的原始代表區(qū)。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS April 6, 2009, doi: 10.1073/pnas.0809614106
Re-emergence of hand-muscle representations in human motor cortex after hand allograft
Claudia D. Vargasa,1, Antoine Aballéaa, érika C. Rodriguesa,1, Karen T. Reillya, Catherine Merciera,2, Palmina Petruzzob, Jean M. Dubernardb and Angela Sirigua,3
The human primary motor cortex (M1) undergoes considerable reorganization in response to traumatic upper limb amputation. The representations of the preserved arm muscles expand, invading portions of M1 previously dedicated to the hand, suggesting that former hand neurons are reassigned to the control of remaining proximal upper limb muscles. Hand allograft offers a unique opportunity to study the reversibility of such long-term cortical changes. We used transcranial magnetic stimulation in patient LB, who underwent bilateral hand transplantation 3 years after a traumatic amputation, to longitudinally track both the emergence of intrinsic (from the donor) hand muscles in M1 as well as changes in the representation of stump (upper arm and forearm) muscles. The same muscles were also mapped in patient CD, the first bilateral hand allograft recipient. Newly transplanted intrinsic muscles acquired a cortical representation in LB's M1 at 10 months postgraft for the left hand and at 26 months for the right hand. The appearance of a cortical representation of transplanted hand muscles in M1 coincided with the shrinkage of stump muscle representations for the left but not for the right side. In patient CD, transcranial magnetic stimulation performed at 51 months postgraft revealed a complete set of intrinsic hand-muscle representations for the left but not the right hand. Our findings show that newly transplanted muscles can be recognized and integrated into the patient's motor cortex.
