Related Experiment Videos
Motoneuronal death during human fetal development
1Department of Psychology, University of California, Berkeley 94720.
The Journal of Comparative Neurology
|October 1, 1987
Summary
Human fetal spinal cord motoneuron numbers significantly decrease early in gestation, with a peak in cell death around 12-16 weeks. Androgens may influence this process, potentially impacting sexually dimorphic motor nuclei.
Area of Science:
- Neuroscience
- Developmental Biology
- Human Embryology
Background:
- Ventral horn motoneurons are crucial for motor function.
- Neuronal development involves programmed cell death (apoptosis).
- The role of androgens in human fetal motoneuron development is not fully understood.
Purpose of the Study:
- To quantify the total number of human spinal cord motoneurons during fetal development.
- To determine the timing and extent of motoneuron loss during gestation.
- To explore the potential influence of androgens on motoneuron survival.
Main Methods:
- Stereological counting of motoneurons in the spinal cords of 19 human fetuses (11-32 menstrual weeks).
- Quantification of pyknotic cells to identify periods of active cell degeneration.
- Correlation of motoneuron counts with gestational age and androgen production periods.
Main Results:
- A significant 35% decline in motoneuron number occurred between 11 and 25 weeks of gestation.
- No further significant motoneuron loss was observed from 25 to 32 weeks.
- Peak motoneuronal degeneration occurred between approximately 12 and 16 weeks of gestation.
Conclusions:
- Human fetal motoneuron numbers undergo substantial reduction early in development.
- This period of cell death coincides with neuromuscular contact and fetal androgen production.
- Androgens may attenuate cell death in specific motor nuclei, influencing final motoneuron numbers, similar to findings in rats.