Tamaki Kato
   Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine
   Position   Assistant Professor
Article types Original article
Language English
Peer review Peer reviewed
Title Axonal damage and behavioral deficits in rats with repetitive exposure of the brain to laser-induced shock waves: Effects of inter-exposure time.
Journal Formal name:Neuroscience letters
Abbreviation:Neurosci Lett
ISSN code:18727972/03043940
Domestic / ForeginForegin
Volume, Issue, Page 749,pp.135722
Author and coauthor Miyai Kosuke, Kawauchi Satoko, Kato Tamaki, Yamamoto Tetsuo, Mukai Yasuo, Yamamoto Taisuke, Sato Shunichi
Publication date 2021/02
Summary Much attention has been given to effects of repeated exposure to a shock wave as a possible factor causing severe higher brain dysfunction and post-traumatic stress disorder (PTSD)-like symptoms in patients with mild to moderate blast-induced traumatic brain injury (bTBI). However, it is unclear how the repeated exposure and the inter-exposure time affect the brain. In this study, we topically applied low-impulse (∼54 Pa·s) laser-induced shock waves (LISWs; peak pressure, ∼75.7 MPa) to the rat brain once or twice with the different inter-exposure times (15 min, 1 h, 3 h, 24 h and 7 days) and examined anxiety-related behavior and motor dysfunction in the rats as well as expression of β-amyloid precursor protein (APP) as an axonal damage marker in the brains of the rats. The averaged APP expression scores for the rat brains doubly-exposed to LISWs with inter-exposure times from 15 min to 24 h were significantly higher than those for rats with a single exposure (P < 0.0001). The rats with double exposure to LISWs showed significantly more frequent anxiety-related behavior (P < 0.05) and poorer motor function (P < 0.01) than those of rats with a single exposure. When the inter-exposure time was extended to 7 days, however, the rats showed no significant differences either in axonal damage score or level of motor dysfunction. The results suggest that the cumulative effects of shock wave-related brain injury can be avoided with an appropriate inter-exposure time. However, clinical bTBI occurs in much more complex environments than those in our model. Further study considering other factors, such as the effects of acceleration, is needed to know the clinically-relevant, necessary inter-exposure time.
DOI 10.1016/j.neulet.2021.135722
PMID 33592306