Yunjeong Lee

The fidelity of motor control requires the precise positional arrangement of motor pools and the establishment of synaptic connections between them. During neural development in the spinal cord, motor nerves project to specific target muscles and receive proprioceptive input from these muscles via the sensorimotor circuit. LIM-homeodomain transcription factors are known to play a crucial role in successively restricting specific motor neuronal fates. However, their exact contribution to limb-based motor pools and locomotor circuits has not been fully understood. To address this, we conducted an investigation into the role of Isl2, a LIM-homeodomain transcription factor, in motor pool organization. We found that deletion of Isl2 led to the dispersion of motor pools, primarily affecting the median motor column (MMC) and lateral motor column (LMC) populations. Additionally, hindlimb motor pools lacked Etv4 expression, and we observed reduced terminal axon branching and disorganized neuromuscular junctions in Isl2-deficient mice. Furthermore, we performed transcriptomic analysis on the spinal cords of Isl2-deficient mice and identified a variety of downregulated genes associated with motor neuron (MN) differentiation, axon development, and synapse organization in hindlimb motor pools. As a consequence of these disruptions, sensorimotor connectivity and hindlimb locomotion were impaired in Isl2-deficient mice. Taken together, our findings highlight the critical role of Isl2 in organizing motor pool position and sensorimotor circuits in hindlimb motor pools. This research provides valuable insights into the molecular mechanisms governing motor control and its potential implications for understanding motor-related disorders in humans.

본 연구의 목적은 중장년 경력단절여성의 구직행동에 미치는 요인을 규명하고자 한다. 충청남도 지역의 취업훈련프로그램에 참여하고 있는 중장년 경력단절여성 176명을 연구대상으로 하였으며, 수집된 자료는 SPSS 22.0프로그램으로 분석하였다. 회귀분석 결과, 경력단절여성의 경력단절 기간, 구직효능감, 재취업 욕구가 구직행동에 유의미한 영향을 미치는 것으로 나타났다. 즉, 경력단절 기간이 짧고, 사회적 욕구가 낮을수록, 구직효능감과 개인적 욕구, 경제적 욕구가 높을수록 구직행동이 높음을 알 수 있다. 이러한 결과를 토대로 경력단절여성을 대상으로 하는 취업훈련프로그램에 기술관련교육 외에도 자신감을 강화시켜주는 직업교육이 포함되어야 하며 지역사회에서 다양한 일자리가 개발되어야 함을 제언하였다.