Radiation effects on neural precursor cells in the dentate gyrus

Abstract

Ionizing irradiation is an effective treatment for intracranial tumors but is limited by the potential adverse effects induced in surrounding normal brain. These effects can include cognitive impairments, and whereas the pathogenesis of such injury has not yet been definitively established, it may involve injury to the neurogenic cell population that exists in the dentate subgranular zone (SGZ) of the hippocampus. Understanding the issues surrounding this topic could have a major impact in the management of specific sequelae associated with cranial irradiation. Although radiation is now becoming a useful tool in investigations into the biology of neurogenesis, the perspective of this review is directed more toward the potential relevance of studying radiation and the stem/precursor cell response.

Early Brain Response to Low-Dose Radiation Exposure Involves Molecular Networks and Pathways Associated with Cognitive Functions, Advanced Aging and Alzheimer's Disease

“…The adult brain is generally considered insensitive to ionizing radiation due to the relatively radioresistant nature of neurons to cell killing (9), but a small population of neuronal precursor cells are relatively sensitive (10)(11)(12)(13). Radiation exposures to human brain, such as external beam radiotherapy, have been associated with neurological damage and cognitive impairment especially in children (14,15).…”

Análises Matemáticas Da Atividade Eletrica Cerebral De Ratos Expostos a Radiação Ionizante

“…Entretanto, essa modalidade de terapia pode ocasionar alterações cerebrais que geram danos ao indivíduo, incluindo, cognitivos (GARCIA, 2015;ANDRES-MACH, 2008; MONJE, 2003; LOGANOVSKY, 2001). Além disso, a exposição do indivíduo à radiação ionizante (RI) pode causar efeitos diretos e indiretos nas estruturas vivas.…”

“…Pesquisas demostram que as células neurogênicas localizadas na zona subgranular (SGZ), que dão origem aos neurônios do giro denteado do hipocampo (CHEN, 2008), são sensíveis à radiação ionizantes, pois doses que variam entre 0,4 Gy e 18 Gy podem levar a apoptose dessas células. Após 48 horas da exposição à radiação ionizante é possível observar uma redução da proliferação de células, da diferenciação celular e aumento da apoptose, que podem persistir durante meses (ANDRES-MACH, 2008;MONJE, 2003). Alguns estudos apoiam a hipótese de que essa diminuição da neurogênese contribui para os déficits cognitivos apresentados por pacientes após a radioterapia craniana (MONJE, 2003).…”

Once the Light Touch to the Brain: Cytotoxic Effects of Low-Dose Gamma-Ray, Laser Light, and Visible Light on Rat Neuronal Cell Culture

“…Ionizing radiation has high energy to remove electrons from atoms creating ions. Ionizing radiation is effective and commonly used for the treatment of intracranial tumors, but it also induces potential adverse effects in the normal brain tissue which is associated with serious morphologic and functional deficits [4][5][6]. X-ray and gamma-ray are typical examples of ionizing radiation widely used for medical purposes such as diagnostic radiology and treatment of cancer [7].…”