Related Experiment Video
Updated: May 10, 2026
10:45
Double In Utero Electroporation to Target Temporally and Spatially Separated Cell Populations
Published on: June 14, 2020
Axon position within the corpus callosum determines contralateral cortical projection
Jing Zhou1, Yunqing Wen, Liang She
1Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Summary
Axon position in the corpus callosum (CC) guides homotopic projections. Even when semaphorin signaling is disrupted, orderly axon positioning remains critical for correct contralateral cortical connections.
Area of Science:
- Neuroscience
- Developmental Biology
- Axon Guidance
Background:
- The precise wiring of interhemispheric connections via the corpus callosum (CC) is crucial for brain function.
- How developing axons navigate to their correct targets in the contralateral cortex is not fully understood.
Purpose of the Study:
- To investigate the role of axonal position within the CC in establishing homotopic projections.
- To determine if orderly axon positioning is essential for accurate contralateral targeting.
Main Methods:
- Axon labeling in mice to visualize callosal projections.
- Disruption of semaphorin3A/neuropilin-1 signaling to assess its impact on axon organization.
- Analysis of axonal projections at different developmental stages.
Main Results:
- Callosal axons exhibit orderly segregation within the CC based on their cortical origin.
- Disruption of semaphorin3A/neuropilin-1 signaling disturbed normal axonal order but did not abolish the positional guidance mechanism.
- Axon position within the CC remained a determinant of contralateral projection, leading to severe disruptions in homotopic targeting.
Conclusions:
- Orderly axonal positioning within the corpus callosum is a key factor in forming precise homotopic interhemispheric projections.
- This positional information plays a primary role in guiding axons to their correct contralateral cortical targets.
Related Concept Videos
01:05Cerebral Hemispheres
The human brain, a complex organ, is functionally divided into two cerebral hemispheres—left and right. These hemispheres are interconnected by a structure of paramount importance, the corpus callosum. This substantial bundle of neural fibers is not just a bridge between the hemispheres but a crucial element for the brain's comprehensive functioning. It enables efficient communication between the two hemispheres, allowing each side of the brain to control and receive sensory and motor...
01:28Lateralization
Brain lateralization refers to the division of mental processes and functions between the two hemispheres of the brain, a phenomenon that optimizes neural efficiency and underpins complex abilities in humans. This specialization allows each hemisphere to perform tasks where it has a comparative advantage, facilitating more refined cognitive capabilities across different domains.
01:23Somatosensory, Motor, and Association Cortex
The somatosensory cortex in the parietal lobes is crucial for interpreting sensory data such as touch, temperature, and proprioception. The somatosensory cortex, situated in the parietal lobes, plays a vital role in interpreting sensory information like touch, temperature, and proprioception—awareness of body position. This specialized brain region features an organized structure wherein neurons at the top primarily process sensations originating from the lower body. In contrast, those at the...
01:14Motor and Sensory Areas of the Cortex
The cerebral cortex, the brain's outermost layer, is pivotal in processing complex cognitive tasks, emotions, and various sensory inputs and executing voluntary motor activities. This intricate structure is divided into three primary functional areas: the motor areas, sensory areas, and association areas.
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex.
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex.
01:22Lobes of the Cerebrum
The cerebral cortex, a critical structure of the brain, is intricately divided into two hemispheres, each consisting of four distinct lobes: occipital, temporal, frontal, and parietal. These lobes function cooperatively to regulate various cognitive and sensory functions, forming the basis of our complex neural capabilities.
Frontal lobe
The frontal lobes, located behind the forehead, are the command center of our brain, controlling personality, intelligence, and voluntary muscle movements.
Frontal lobe
The frontal lobes, located behind the forehead, are the command center of our brain, controlling personality, intelligence, and voluntary muscle movements.
01:11Cerebrum: Anatomical Overview II
Each cerebral hemisphere can be divided into three main regions. The outermost region, the cerebral cortex, is a thin layer (2 to 4 millimeters thick) made up of gray matter, consisting of neuron cell bodies, dendrites, glial cells, and blood vessels. The middle region, or white matter, is primarily composed of myelinated nerve fibers organized into three types of large tracts: association fibers, commissures, and projection fibers. Association fibers connect different areas within the same...