Related Experiment Video
Updated: Jan 4, 2026
Functional Interrogation of Adult Hypothalamic Neurogenesis with Focal Radiological Inhibition
Published on: November 14, 2013
X-irradiation of developing hippocampal neurons causes changes in neuron population phenotypes, dendritic morphology
Anggraeini Puspitasari1, Hiroyuki Yamazaki2, Hidemasa Kawamura3
1Gunma University Initiative for Advanced Research, Maebashi, Japan.
Abstract:
The effects of X-irradiation on developing neurons and their functions are unclear. We used primary cultures of mouse hippocampal neurons to investigate the effects of X-irradiation on cell death in developing neurons by analyzing caspase-3, MAP2 and DAPI-labeled cells, and the phenotypes and function of surviving neurons, by examining GAD67-positive cells as a GABAergic marker, and the synaptic markers synapsin 1, drebrin and PSD-95 through its maturation. One-day in vitro (DIV 1) cells were exposed to 0.5 Gy or 1 Gy of X-rays. A significant increase in the percentage of activated caspase-3, a decrease in the number of MAP2/DAPI-positive cells and change in the percentage of GAD67 positive neurons, compared with sham controls, were found 6 days after 1 Gy and 13 days after 0.5 Gy of X-rays. The expression of PSD-95 and drebrin, as well as drebrin clusters, in the remaining neurons was decreased at DIV 21, in both 0.5 Gy and on 1 Gy-irradiation there was a reduced number of dendritic intersection as well. Together, our findings show that 0.5 Gy and 1 Gy of X-irradiation at DIV 1 not only causes neuronal cell death but elicits an increase in the percentage of inhibitory neurons, changes in the dendrites and decrease in expression of important synaptic proteins in the surviving neurons at maturity 3 weeks after exposure.
Insights
X-irradiation of developing mouse neurons at DIV 1 caused cell death and altered neuronal function. Surviving neurons showed increased inhibitory neurons, dendritic changes, and reduced synaptic protein expression.
Area of Science:
- Neuroscience
- Developmental Biology
- Radiation Biology
Background:
- The impact of X-irradiation on developing neurons remains poorly understood.
- Investigating neuronal development and function post-irradiation is crucial for understanding potential risks.
Purpose of the Study:
- To investigate the effects of low-dose X-irradiation on neuronal cell death and function in developing mouse hippocampal cultures.
- To analyze the impact on neuronal maturation, synaptic protein expression, and dendritic structure.
Main Methods:
- Primary mouse hippocampal neurons were irradiated at 1 day in vitro (DIV 1) with 0.5 Gy or 1 Gy X-rays.
- Assessed cell death using caspase-3, MAP2, and DAPI staining.
- Evaluated neuronal phenotypes and function by analyzing GAD67, synapsin 1, drebrin, and PSD-95 expression, alongside dendritic morphology.
Main Results:
- X-irradiation significantly increased activated caspase-3 and decreased MAP2/DAPI-positive cells, indicating cell death.
- A shift in GAD67-positive (inhibitory) neuron percentage was observed post-irradiation.
- Synaptic protein expression (PSD-95, drebrin) and dendritic complexity were reduced in surviving neurons at 3 weeks post-exposure.
Conclusions:
- Low-dose X-irradiation during early neuronal development induces significant cell death.
- Surviving neurons exhibit altered inhibitory neuron populations, impaired dendritic development, and reduced synaptic protein expression, impacting neuronal function.
