Radiation Effects on Central Nervous System Function

Ionising radiation poses significant risks to central nervous system function across clinical and environmental settings. In therapeutic contexts, cranial radiotherapy for tumour control can induce acute DNA damage, disruption of the blood–brain barrier and chronic microvascular injury, culminating in progressive impairments of memory, attention and executive function. In preclinical models, hippocampal neurogenesis is markedly suppressed and synaptic plasticity altered, while activated microglia sustain a pro-inflammatory milieu that exacerbates neuronal dysfunction. In the context of deep-space missions, exposure to galactic cosmic radiation comprises a spectrum of high-energy charged particles that remodel neurotransmitter networks in the prefrontal cortex, slow attentional processing and elevate reaction times. Interactions between immune-mediated inflammation and subtle structural changes in white and grey matter underpin long-term cognitive deficits. Practical applications of this work include hippocampal-sparing radiotherapy protocols and targeted immunomodulatory strategies, as well as enhanced shielding and countermeasure development for astronauts. Continued exploration of dose fractionation, particle energy spectra and cellular dynamics remains essential to safeguard neurological health in diverse exposure scenarios.

Research from Nature Portfolio

Recent studies have employed complex simulated cosmic ray fields to mirror deep-space exposure and revealed that acute and chronic multi-ion radiation reorganises neurotransmitter networks in the prefrontal cortex. Detailed analyses showed that dopamine responsiveness is abolished after high-dose simulated galactic cosmic radiation, while chronic exposure alters levels of multiple neurotransmitters, leading to slowed attentional processing and elevated reaction times. These findings offer quantitative insight into space radiation-induced neurocognitive deficits and support the development of targeted countermeasures. Another investigation into cranial radiotherapy revealed that depletion of microglia via colony-stimulating factor-1 receptor inhibition prevented the emergence of long-term cognitive deficits in rodent models. By effectively eliminating activated microglia post-irradiation, animals maintained normal hippocampal and prefrontal function, suggesting that transient suppression of the brain’s innate immune cells can ameliorate radiation-induced cognitive decline.

Radiation Effects on Central Nervous System Function publication trend

The graph below shows the total number of articles in radiation effects on central nervous system function across all publications each year (not limited to Nature Index journals).

Technical terms

Ionising radiation: High-energy radiation capable of removing electrons from atoms or molecules, causing cellular damage.

Microglia: Resident immune cells of the central nervous system responsible for surveillance and response to injury or infection.

Neurogenesis: The process of generating new neurons, predominantly in the hippocampus, essential for memory formation.

Synaptic plasticity: The ability of neuronal connections to strengthen or weaken over time in response to activity.

Hippocampus: A brain region critical for learning, memory consolidation and spatial navigation.

Prefrontal cortex: Frontal brain region involved in attention, executive function and decision-making.

Galactic cosmic radiation: A mixture of high-energy charged particles originating from outside the solar system that poses a risk during deep-space missions.

References

1. Complex 33-beam simulated galactic cosmic radiation exposure impacts cognitive function and prefrontal cortex neurotransmitter networks in male mice. Nature Communications (2023).
2. Cranial irradiation disrupts homeostatic microglial dynamic behavior. Journal of Neuroinflammation (2024).
3. Elimination of microglia improves cognitive function following cranial irradiation. Scientific Reports (2016).
4. Molecular, Cellular and Functional Effects of Radiation-Induced Brain Injury: A Review. International Journal of Molecular Sciences (2015).