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Updated: Nov 8, 2025
Sex Stratified Neuronal Cultures to Study Ischemic Cell Death Pathways
Published on: December 9, 2013
Cell death in the male and female rat medial prefrontal cortex during early postnatal development
Elli P Sellinger1, Carly M Drzewiecki1, Jari Willing2
1Program in Neuroscience, University of Illinois at Urbana-Champaign, Champaign, IL 61801, United States.
Insights
Programmed cell death in the rat medial prefrontal cortex peaks around postnatal day 8 in both sexes. This cell death pattern persists longer in females, offering insights into neurodevelopmental studies.
Area of Science:
- Neuroscience
- Developmental Biology
- Cell Biology
Background:
- Programmed cell death (apoptosis) is crucial for neurodevelopment, exhibiting specific timing and patterns.
- The early postnatal brain is vulnerable to environmental factors, impacting neurodevelopmental trajectories.
- The medial prefrontal cortex (mPFC) is implicated in human developmental disorders.
Purpose of the Study:
- To determine the precise timing of peak programmed cell death in the male and female rat medial prefrontal cortex (mPFC).
- To establish a temporal profile of cell death in the mPFC relevant to neurodevelopmental research.
Main Methods:
- Stereological analysis of pyknotic (dying) cells and live neurons in Nissl-stained rat mPFC tissue.
- Data collected from male and female rats at multiple postnatal days (P2-P25).
- Quantification of pyknotic cell density and the ratio of pyknotic to live neurons.
Main Results:
- A significant peak in the pyknotic to live neuron ratio occurred on postnatal day 8 (P8) in both males and females.
- This elevated cell death ratio persisted until P12 in females.
- Pyknotic cell density also peaked on P8 in both sexes, with a similar extension to P12 in females.
Conclusions:
- The timing of peak cell death in the rat mPFC is established, with sex-specific differences in duration.
- Understanding this precise timing is essential for designing studies on environmental influences on neurodevelopment.
- This research informs experimental designs investigating disruptions to programmed cell death in the developing brain.
Abstract:
Apoptosis, programmed cell death, is a critical component of neurodevelopment occurring in temporal, spatial, and at times, sex-specific, patterns across the cortex during the early postnatal period. During this time, the brain is particularly susceptible to environmental influences that are often used in animal models of neurodevelopmental disorders. In the present study, the timing of peak cell death was assessed by the presence of pyknotic cells in the male and female rat medial prefrontal cortex (mPFC), a cortical region that in humans, is often involved in developmental disorders. One male and one female rat per litter were sacrificed at the following ages: postnatal day (P)2, 4, 6, 8, 10, 12, 14, 16, 18, and 25. The mPFC was Nissl-stained, the densities of pyknotic cells and live neurons were stereologically collected, and the number of pyknotic cells per 100 live neurons, pyknotic cell density, and neuron density were analyzed. Males and females showed a significant peak in the ratio of pyknotic to live neurons on P8, and in females, this elevation persisted through P12. Likewise, the density of pyknotic cells peaked on P8 in both sexes and persisted through P12 in females. The timing of cell death within the rat mPFC will inform study design in experiments that employ early environmental manipulations that might disrupt this process.
