Effects of fatigue-predominant subhealth on mechanical and thermal pain sensitivity in mice / 中国药理学通报

Aim: To study the effects of the fatigue-predominant subhealth on mechanical and thermal pain sensitivity in mice. Methods: Kunming mice were randomly divided into two groups (n = 10); normal control group (control), fatigue-predominant subhealth model group (fatigue). The physiological behavior, rota-rod test and blood routine indexes were examined. The paw withdrawal mechanical threshold (PWMT) and the paw withdrawal thermal latency (PWTL) were measured in order to reflect the change of the mechanical and thermal pain sensitivity. Results: Compared to control group, the fur of model group was markedly pale, the time of rota-rod test was significantly lower (P < 0. 01), the data of blood cells was nearly the same, the outcome of PWMT was increased (P < 0. 01), and PWTL was decreased (P < 0. 01). Conclusions The fatigue-predominant subhealth reduces the mechanical pain sensitivity and increases the thermal pain sensitivity in mice.

Diet rich in date palm fruits improves memory, learning and reduces beta amyloid in transgenic mouse model of Alzheimer’s disease.

Background: At present, the treatment options available to delay the onset or slow down the progression of Alzheimer’s disease (AD) are not effective. Recent studies have suggested that diet and lifestyle factors may represent protective strategies to minimize the risk of developing AD. Date palm fruits are a good source of dietary fiber and are rich in total phenolics and natural antioxidants, such as anthocyanins, ferulic acid, protocatechuic acid and caffeic acid. These polyphenolic compounds have been shown to be neuroprotective in different model systems. Objective: We investigated whether dietary supplementation with 2% and 4% date palm fruits (grown in Oman) could reduce cognitive and behavioral deficits in a transgenic mouse model for AD (amyloid precursor protein [APPsw]/Tg2576). Materials and Methods: The experimental groups of APP‑transgenic mice from the age of 4 months were fed custom‑mix diets (pellets) containing 2% and 4% date fruits. We assessed spatial memory and learning ability, psychomotor coordination, and anxiety‑related behavior in all the animals at the age of 4 months and after 14 months of treatment using the Morris water maze test, rota‑rod test, elevated plus maze test, and open‑field test. We have also analyzed the levels of amyloid beta (Aβ) protein (1–40 and 1–42) in plasma of control and experimental animals. Results: Standard diet‑fed Tg mice showed significant memory deficits, increased anxiety‑related behavior, and severe impairment in spatial learning ability, position discrimination learning ability and motor coordination when compared to wild‑type on the same diet and Tg mice fed 2% and 4% date supplementation at the age of 18 months. The levels of both Aβ proteins were significantly lowered in date fruits supplemented groups than the Tg mice without the diet supplement. The neuroprotective effect offered by 4% date fruits diet to AD mice is higher than 2% date fruits diet. Conclusions: Our results suggest that date fruits dietary supplementation may have beneficial effects in lowering the risk, delaying the onset or slowing down the progression of AD.

Differential gene expression pattern in brains of acrylamide-administered mice / 대한수의학회지

The present study was performed to evaluate the relationship between the neurotoxicity of acrylamide and the differential gene expression pattern in mice. Both locomotor test and rota-rod test showed that the group treated with higher than 30 mg/kg/day of acrylamide caused impaired motor activity in mice. Based on cDNA microarray analysis of mouse brain, myelin basic protein gene, kinesin family member 5B gene, and fibroblast growth factor (FGF) 1 and its receptor genes were down-regulated by acrylamide. The genes are known to be essential for neurofilament synthesis, axonal transport, and neuro-protection, respectively. Interestingly, both FGF 1 and its receptor genes were down-regulated. Genes involved in nucleic acid binding such as AU RNA binding protein/enoyl-coA hydratase, translation initiation factor (TIF) 2 alpha kinase 4, activating transcription factor 2, and U2AF 1 related sequence 1 genes were down-regulated. More interesting finding was that genes of both catalytic and regulatory subunit of protein phosphatases which are important for signal transduction pathways were down-regulated. Here, we propose that acrylamide induces neurotoxicity by regulation of genes associated with neurofilament synthesis, axonal transport, neuro-protection, and signal transduction pathways.

Anxiolytic Effect of a Combination of Green Tea Extract and L-theanine / 한국실험동물학회지

The purpose of this study is to investigate whether the combination of green tea extract (GTE) and L-theanine has an anxiolytic effect by oral administration through behavioral tests and neurtransmitters (or hormone) anaylses. Four week oral administration of GTE (24 mg/kg), L-theanine (4 mg/kg) or their combination showed anxiety-reducing effects determined by increasing numbers of head-dips in a hole board test and reducing retention time in a rota-rod test without changing spontaneous locomotor activity. Biochemical analyses indicated that the test materials decreased dopamine (DA), noradrenaline (NA), corticosterone (CS) and increased serotonin (5-HT) levels in brain cortex, hippocampus, and striatum, which suggests a possible mechanism of previous behavioral tests. Although the synergistic effects of GTE and L-theanine combination were not observed on the behavioral test, its effects on neurotransmitters (NA, CS) were synergistic and comparable to diazepam (2 mg/kg i.p.) with much less muscle relaxation side effect. Therefore, a combination of GTE and L-theanine may be useful as a functional food ingredient having an anxiolytic effect.

Effect of Cerebral Motor Cortex Stimulation in Amyotrophic Lateral Sclerosis Model: A Preliminary Controlled Study

OBJECTIVE: To observe the effect of the depolarizing stimulation in amyotrophic lateral sclerosis (ALS) mouse model on the survival and behavioral performance. METHOD: Transgenic male mouse model of ALS at the age of 9~11 weeks were divided into sham control group (n=10) and stimulation group (n=9). Electrode was implanted in the motor cortex in left hemisphere. Movement thresholds (MT) were regularly checked. Half threshold of MT, unipolar, and continuous electrical stimulation (frequency, 50 Hz; pulse duration, 220micron s) was delivered through implanted electrode. Behavioral tests including Rota-rod and Paw-grip endurance were checked every day. RESULTS: Induction of symptom was delayed in 8 days in stimulation than sham control group. However, there was no significant difference in survival in both groups. Behavioral tests showed that stimulation group is significantly better than sham group in Rota-rod (11~15 weeks) and in grip endurance (11~14, 16 weeks). MT was always between 1.0 volt and 3.2 volt in sham group, however, MT was between 0.8 volt and 2.8 volt in stimulation group. MT was jumped up around the time of death in both groups. CONCLUSION: Electrical stimulation is considered to be one of possible trial methods in ALS model. However, parameters of the stimulation in the experiment should be modified for better results.