Search

Background and purpose: Stress, especially immobility stress, is quite common and one of the most important and influential risk factors in neurological disorders. This study aimed to investigate the effect of acute and chronic immobility stress on the level of cortical and hippocampal oxidative stress indicators and memory impairment following global cerebral ischemia. Experimental approach: In this study, 48 male Wistar rats were randomly divided into 6 groups: 1, sham (S); 2, sham-acute stress (SSA); 3, sham-chronic stress (SSC); 4, ischemia (IS); 5, ischemia-acute stress (ISA); 6, ischemia-chronic stress (ISC). The Morris water maze (MWM) test was performed 14 days after surgery, and cortisol levels and oxidative stress factors such as malondialdehyde MDA and total thiol were measured. Findings/Results: In the MWM test, the time to find the platform (latency time) in the ISC and IS groups significantly increased compared to the S group. The time spent in the target quarter in these two groups was significantly reduced compared to the S group on the day of the probe. The results showed a significant increase in cortisol levels and malondialdehyde concentration in the ISA, ISC, and IS groups compared to the S group, but there was no significant difference in total thiol concentration. No significant difference was observed in the level of oxidative stress factors in the cortex. Conclusion and implication: Chronic immobility stress could reduce antioxidant factors in the hippocampus and exacerbate memory impairment caused by global ischemia. [ABSTRACT FROM AUTHOR]

Objective: Stroke is a highly prevalent and devastating condition affecting millions worldwide. The Devil's Claw (DCW) plant is a native African plant whose anti-inflammatory, antioxidant, and neuroprotective properties have been investigated. We postulated that DCW could protect the brain injury caused by cerebral ischemia. Materials and Methods: The rats were randomly divided into four groups. The sham and control (Ctrl) groups received pretreatment with a distilled water vehicle. Doses of 200 and 400 mg/kg were selected for pretreatment with DCW. The filament or intravascular occlusion method was used for middle cerebral artery occlusion (MCAO). The Triphenyl tetrazolium chloride (TTC) staining method was used to investigate the infarct zone and penumbra volume. The neuroprotective effect of DCW was measured by hematoxylin staining. Movement performance was evaluated from neurological deficit score, rotarod performance, and open field tests. Results: TTC staining showed that the DCW/400 group could maintain the penumbra's structure and reduce the infarct volume compared to the Ctrl group (p<0.001). Histological studies confirmed the neuroprotective properties of DCW at doses of 200 and 400 mg/kg compared to the Ctrl group (p<0.01 and p<0.0001, respectively). The results of behavioral tests showed an improvement in behavioral performance in pretreatment 400 mg/kg doses compare to Ctrl group (p<0.0001). Conclusion: The study showed that pretreatment with DCW with its neuron protection potential reduces the infarct area and restores motor function after MCAO. [ABSTRACT FROM AUTHOR]

Objective(s): Memory and cognition impairments are the most important secondary effects of spinal cord injury (SCI) in the hippocampus. Therefore, the present study aimed to examine the effect of implantation of polycaprolactone/functionalized multiwall carbon nanotube (PCL/f-MWCNT) scaffold along with ellagic acid loaded liposome (EA@lip) in neurological function recovery and hippocampus deficit after SCI. Materials and Methods: Twenty-four female Wistar rats were randomly assigned into 4 groups (n=6): Ctrl-group (laminectomy without SCI), Ctrl+ group (SCI), PCL/CNT group (implantation of PCL/f-MWCNT scaffold) and PCL/CNT/EA group (implantation of PCL/f-MWCNT/EA@lip scaffold). The injury model was the dorsal hemisection at the T9 level. Characterization of EA@lip made by remote loading method was done by transmission electron microscopy and dynamic light scattering. Also, the morphology of PCL/f-MWCNT fibers was investigated by field-emission scanning electron microscopy (FE-SEM). Behavioral tests were used to evaluate the neurobehavioral performance of the animals. After 4-weeks, excitatory postsynaptic potential was recorded from the CA1 area of the hippocampus. Hippocampal mRNA levels of amyloid beta precursor protein (APP), cyclic nucleotide phosphodiesterase (CNP), glutamate ionotropic receptor kainate type subunit 2 (GRIK2) and syntaxin-binding protein 1 (Munc 18-1) were assayed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Results: We demonstrated that, after implanting the PCL/CNT scaffold with or without EA@lip, the hippocampal action potential improved by increasing the slope and amplitude of fEPSP compared to the Ctrl+ group. RT-qPCR data showed that the expression of CNP and Munc 18-1 increased, and the expression of APP and GRIK2 decreased, in the groups that received PCL/CNT with or without EA@lip compared to the injury group. We also proved that the treatment with PCL/CNT/EA@lip improved behavioral performance compared to the Ctrl+ and PCL/CNT groups. Conclusion: This study demonstrated that PCL/f-MWCNT/EA@lip scaffold implantation improves functional potential and alters the expression of memory-related genes in the hippocampus post-injury. [ABSTRACT FROM AUTHOR]