Neurological Exam in Rats Following Stroke and Traumatic Brain Injury

Comparison of the protective effects of silymarin and thymoquinone in the focal cerebral ischemia-reperfusion rat model

Silymarin and thymoquinone exert neuroprotective effects, although their combined effects in focal cerebral ischemia/reperfusion (I/R) models are unknown. We compared the effect of silymarin and thymoquinone in an I/R rat model. Wistar rats were divided into five groups: SHAM, REP (I/R), SIR (200 mg/kg silymarin+I/R), TIR (3 mg/kg thymoquinone+I/R), and STIR (200 mg/kg silymarin+3-mg thymoquinone+I/R). The rats underwent bilateral carotid artery occlusion for 30 min and neurological assessments 24 h thereafter. Apoptosis was evaluated using anti-caspase-3 and terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) assays. Astrocyte activation was determined using an anti-GFAP antibody. Total antioxidant status (TAS), total oxidant status (TOS), and trimethylamine N-oxide (TMAO) levels were measured. SHAM and REP rats had the lowest and highest neurological scores, respectively (p = 0.001). REP rats showed greater deterioration than SIR, TIR, and STIR rats. SIR, TIR, and STIR rats had fewer TUNEL and caspase-3-positive cells than REP rats (p<0.05). GFAP expression was higher in REP rats (p<0.05) than in SIR, TIR, and STIR rats (p<0.05). SIR and TIR rats showed higher TAS than REP rats (p<0.05). SIR, TIR, and STIR rats had lower TMAO values than REP and SHAM rats (p<0.05). Silymarin/thymoquinone reduces impairment, apoptosis, and astrocyte activation. Combination therapy reduces TMAO levels.

Oxidative stress associated with spatial memory impairment and social olfactory deterioration in female mice reveals premature aging aroused by perinatal protein malnutrition

Early-life adversity, like perinatal protein malnutrition, increases the vulnerability to develop long-term alterations in brain structures and function. This study aimed to determine whether perinatal protein malnutrition predisposes to premature aging in a murine model and to assess the cellular and molecular mechanisms involved. To this end, mouse dams were fed either with a normal (NP, casein 20%) or a low-protein diet (LP, casein 8%) during gestation and lactation. Female offspring were evaluated at 2, 7 and 12 months of age. Positron emission tomography analysis showed alterations in the hippocampal CA3 region and the accessory olfactory bulb of LP mice during aging. Protein malnutrition impaired spatial memory, coinciding with higher levels of reactive oxygen species in the hippocampus and sirt7 upregulation. Protein malnutrition also led to higher senescence-associated β-galactosidase activity and p21 expression. LP-12-month-old mice showed a higher number of newborn neurons that did not complete the maturation process. The social-odor discrimination in LP mice was impaired along life. In the olfactory bulb of LP mice, the senescence marker p21 was upregulated, coinciding with a downregulation of Sirt2 and Sirt7. Also, LP-12-month-old mice showed a downregulation of catalase and glutathione peroxidase, and LP-2-month-old mice showed a higher number of newborn neurons in the subventricular zone, which then returned to normal values. Our results show that perinatal protein malnutrition causes long-term impairment in cognitive and olfactory skills through an accelerated senescence phenotype accompanied by an increase in oxidative stress and altered sirtuin expression in the hippocampus and olfactory bulb.

Behavioral tests for evaluating the characteristics of brain diseases in rodent models: Optimal choices for improved outcomes (Review)

Behavioral assessment is the dominant approach for evaluating whether animal models of brain diseases can successfully mimic the clinical characteristics of diseases. At present, most research regarding brain diseases involves the use of rodent models. While studies have reported numerous methods of behavioral assessments in rodent models of brain diseases, each with different principles, procedures, and assessment criteria, only few reviews have focused on characterizing and differentiating these methods based on applications for which they are most appropriate. Therefore, in the present review, the representative behavioral tests in rodent models of brain diseases were compared and differentiated, aiming to provide convenience for researchers in selecting the optimal methods for their studies.