scholarly journals Sex Differences in Behavioral Sensitivities After Traumatic Brain Injury

2020 ◽  
Vol 11 ◽  
Author(s):  
Ann N. Hoffman ◽  
Sonya L. Watson ◽  
Anna S. Makridis ◽  
Anisha Y. Patel ◽  
Sarah T. Gonzalez ◽  
...  

Traumatic brain injury (TBI) is associated with high rates of post-injury psychiatric and neurological comorbidities. TBI is more common in males than females despite females reporting more symptoms and longer recovery following TBI and concussion. Both pain and mental health conditions like anxiety and post-traumatic stress disorder (PTSD) are more common in women in the general population, however the dimorphic comorbidity in the TBI population is not well-understood. TBI may predispose the development of maladaptive anxiety or PTSD following a traumatic stressor, and the impact of sex on this interaction has not been investigated. We have shown that white noise is noxious to male rats following fluid percussion injury (FPI) and increases fear learning when used in auditory fear conditioning, but it is unclear whether females exhibit a similar phenotype. Adult female and male rats received either lateral FPI or sham surgery and 48 h later received behavioral training. We first investigated sex differences in response to 75 dB white noise followed by white noise-signaled fear conditioning. FPI groups exhibited defensive behavior to the white noise, which was significantly more robust in females, suggesting FPI increased auditory sensitivity. In another experiment, we asked how FPI affects contextual fear learning in females and males following unsignaled footshocks of either strong (0.9 mA) or weaker (0.5 mA) intensity. We saw that FPI led to rapid acquisition of contextual fear compared to sham. A consistent pattern of increased contextual fear after TBI was apparent in both sexes across experiments under differing conditioning protocols. Using a light gradient open field task we found that FPI females showed a defensive photophobia response to light, a novel finding supporting TBI enhanced sensory sensitivity across modalities in females. General behavioral differences among our measures were observed between sexes and discussed with respect to interpretations of TBI effects for each sex. Together our data support enhanced fear following a traumatic stressor after TBI in both sexes, where females show greater sensitivity to sensory stimuli across multiple modalities. These data demonstrate sex differences in emergent defensive phenotypes following TBI that may contribute to comorbid PTSD, anxiety, and other neurological comorbidities.

2018 ◽  
Vol 45 (6) ◽  
pp. E16 ◽  
Author(s):  
Lily H. Kim ◽  
Jennifer L. Quon ◽  
Felicia W. Sun ◽  
Kristen M. Wortman ◽  
Maheen M. Adamson ◽  
...  

The impact of traumatic brain injury (TBI) has been demonstrated in various studies with respect to prevalence, morbidity, and mortality data. Many of the patients burdened with long-term sequelae of TBI are veterans. Although fewer in number, female veterans with TBI have been suggested to suffer from unique physical, mental, and social challenges. However, there remains a significant knowledge gap in the sex differences in TBI. Increased female representation in the military heralds an increased risk of TBI for female soldiers, and medical professionals must be prepared to address the unique health challenges in the face of changing demographics among the veteran TBI population. In this review, the authors aimed to present the current understanding of sex differences in TBI in the veteran population and suggest directions for future investigations.


2011 ◽  
Vol 26 (2) ◽  
pp. 94-100 ◽  
Author(s):  
Danilo dos Santos Silva ◽  
José Nazareno Pearce de Oliveira Brito ◽  
Jerúsia Oliveira Ibiapina ◽  
Marcel Fernando Miranda Batista Lima ◽  
Andréa Ribeiro Gonçalves de Vasconcelos Medeiros ◽  
...  

PURPOSE: To investigate the function of an experimental cranium trauma model in rats. METHODS: The equipment, already described in the literature and under discreet adaptations, is composed by a platform that produces closed head impact controlled by weight drop with pre-defined and known energy. 25 Wistar male rats (Rattus norvegicus albinus) were divided into five equal groups that received different quantities of cranial impact energy: G1, G2, G3 and G4 with 0,234J, 0,5J, 0,762J and 1J respectively and G5 (Sham). Under intense analgesia, each group was evaluated clinically in a sequence of intervals and had their encephalon removed for pathologic analysis. RESULTS: Important clinical alterations (convulsions, bradycardia, bradypnea and abnormal postures) and focal pathologic (hematomas and hemorrhages) kept proportion with the intensity of the impact. No fracture was observed and the group 4 had 80% mortality rate. CONCLUSION: The experimental cranium trauma animal model by weight drop is an alternative of low cost and easy reproduction that allows evaluating clinical and pathological alterations in accordance with studies in experimental surgery aims for new traumatic brain injury approach in rats.


2021 ◽  
Author(s):  
Heather M Minchew ◽  
Sarah K Christian ◽  
Paul Keselman ◽  
Jinxiang Hu ◽  
Brian T Andrews ◽  
...  

Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide. Cerebral edema following TBI is known to play a critical role in injury severity and prognosis. In the current study we used multimodal magnetic resonance imaging (MRI) to assess cerebral edema 24 hours after unilateral contusive TBI in male and female rats. We then directly quantified brain water content in the same subjects ex vivo. We found that in male rats, the injured cortex had higher brain water content and lower apparent diffusion coefficient (ADC) values compared with the contralateral side. Females did not show hemispheric differences for these measures. However, both males and females had similarly elevated T2 values in the injured cortex compared with the contralateral side. A strong correlation was observed between brain water content and T2 values in the injured cortex in male rats, but not in females. These findings raise questions about the clinical interpretation of radiological findings pertinent to edema in female TBI patients. A more mechanistic understanding of sex differences and similarities in TBI pathophysiology will help improve patient management and the development of effective treatment strategies for TBI in men and women.


Author(s):  
Jessica M. Wong ◽  
Adam L. Halberstadt ◽  
Humberto A. Sainz ◽  
Kiran S. Mathews ◽  
Brian W. Chu ◽  
...  

Recent studies on military breachers in training environments suggest that there are neurocognitive risks from exposure to repeated low-level blasts. However, the dose accumulation effects from multiple low-level blast exposures and their relation to mild traumatic brain injury (mTBI) are not well understood. This paper presents a controlled neurobehavioral study of behavioral effects from repeated low-level blasts delivered at ten second intervals using a rat model. A custom designed shock tube was developed to deliver repeated low-level blasts to rats at short intervals on the order of seconds. A total of 192 rats were divided into three cohorts of 64 for testing. Each cohort was exposed to a different blast intensity (7.5, 15, or 25 psi reflective pressure with durations <0.25 ms), and each cohort was further divided into four levels of blast repetition (0, 5, 10, or 15 repeats). Shock tube blasts were directed at the rat’s head, and startle with prepulse inhibition (PPI) and fear learning and extinction behavioral tests were performed to evaluate the blast effects. Behavioral testing results showed that repeated low-level blasts can affect PPI and contextual fear recall. PPI was not affected by repeated exposures to 7.5 psi blasts, but repeated 15 and 25 psi blasts disrupted PPI. All cohorts showed significant fear learning, but the highest blast group (25 psi, 15 repeats) had disruptions in spatial memory recall. None of the cohorts showed effects on cued fear recall or fear extinction and retention. The data collected are being used in continuous research to understand how the behavioral changes relate to mTBI, and how these animal tests can be scaled and modeled to interpret possible outcomes for humans.


Author(s):  
Eunyoung Park ◽  
Johnathan G. Lyon ◽  
Melissa Alvarado‐Velez ◽  
Martha I. Betancur ◽  
Nassir Mokarram ◽  
...  

Author(s):  
Ewa Zwierzyńska ◽  
Agata Krupa-Burtnik ◽  
Bogusława Pietrzak

Abstract Background Retigabine belongs to the novel generation of antiepileptic drugs but its complex mechanism of action causes that the drug might be effective in other diseases, for instance, alcohol dependence. It is known that ethanol abuse impaired the function of brain structures associated with memory and learning such as the hippocampus. In our previous study, retigabine reduced hippocampal changes induced by ethanol in the EEG rhythms in rabbits. This study is focused on the impact of retigabine on memory processes in male rats receiving alcohol. Methods Memory was evaluated in various experimental models: Morris water maze, Contextual, and Cued Fear Conditioning tests. Retigabine was administered for 3 weeks directly to the stomach via oral gavage at a dose of 10 mg/kg. Rats received also 20% ethanol (5 g/kg/day in two doses) via oral gavage for 3 weeks and had free access to 5% ethanol in the afternoon and at night. Morris water maze was performed after 1 and 3 weeks of ethanol administration and after 1 week from the discontinuation of ethanol administration. Contextual and Cued Fear Conditioning tests were carried out after 24 h and 72 h of alcohol discontinuation. Results The drug significantly decreased ethanol-induced memory disturbances during alcohol administration as well as slightly improved learning processes after the discontinuation of ethanol administration. Conclusions This beneficial effect of retigabine-ethanol interaction on memory may be a relevant element of the drug’s impact on the development of addiction.


Author(s):  
Fleur Lorton ◽  
Jeanne Simon-Pimmel ◽  
Damien Masson ◽  
Elise Launay ◽  
Christèle Gras-Le Guen ◽  
...  

AbstractObjectivesTo evaluate the impact of implementing a modified Pediatric Emergency Care Applied Research Network (PECARN) rule including the S100B protein assay for managing mild traumatic brain injury (mTBI) in children.MethodsA before-and-after study was conducted in a paediatric emergency department of a French University Hospital from 2013 to 2015. We retrospectively included all consecutive children aged 4 months to 15 years who presented mTBI and were at intermediate risk for clinically important traumatic brain injury (ciTBI). We compared the proportions of CT scans performed and of in-hospital observations before (2013–2014) and after (2014–2015) implementation of a modified PECARN rule including the S100B protein assay.ResultsWe included 1,062 children with mTBI (median age 4.5 years, sex ratio [F/M] 0.73) who were at intermediate risk for ciTBI: 494 (46.5%) during 2013–2014 and 568 (53.5%) during 2014–2015. During 2014–2015, S100B protein was measured in 451 (79.4%) children within 6 h after mTBI. The proportion of CT scans and in-hospital observations significantly decreased between the two periods, from 14.4 to 9.5% (p=0.02) and 73.9–40.5% (p<0.01), respectively. The number of CT scans performed to identify a single ciTBI was reduced by two-thirds, from 18 to 6 CT scans, between 2013–2014 and 2014–2015. All children with ciTBI were identified by the rules.ConclusionsThe implementation of a modified PECARN rule including the S100B protein assay significantly decreased the proportion of CT scans and in-hospital observations for children with mTBI who were at intermediate risk for ciTBI.


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