scholarly journals A low-cost Morris Water Maze for undergraduate research: Construction and demonstration in a rat model of obesity-induced diabetes

2017 ◽  
Author(s):  
Lester Maxwell Gallivan ◽  
Neil Schmitzer-Torbert

The Morris Water Maze (MWM) is a standard task for assessing hippocampal-dependent learning and memory, but the cost of commercial versions of the task may be prohibitive for some undergraduate research projects. We describe the construction of a low-cost MWM for use with rats, and demonstrate the effectiveness of the MWM in a study of the effect of diet-induced obesity on cognitive function in rats. Previous studies have described an impairment in MWM performance in rats fed a high-fat diet combined with streptozotocin injection (to model Type 2 diabetes). We attempted to replicate this finding, and to test the ability of a novel anti-inflammatory treatment to reduce cognitive deficits in the diabetic model. Across five days of hidden-platform training, rats in all groups (normal pellet diet vs. high-fat diet, vehicle vs. treatment) improved on the water maze at similar rates. On a 30-second probe trial, each group showed a preference for the target quadrant used during training. On the probe trial, rats in the high-fat diet group receiving vehicle injections performed significantly better than rats on a normal pellet diet receiving vehicle injections, or on a high-fat diet receiving treatment. These results did not replicate previous findings that a high-fat diet combined with streptozotocin injections produces deficits in the water maze. However, the results did validate the effectiveness of a low-cost water maze constructed from commonly available materials for hidden platform water maze training, which we expect may be of use to other undergraduate researchers interested in learning and memory.

2020 ◽  
Vol 17 (11) ◽  
pp. 1194-1199
Author(s):  
Apsorn SATTAYAKHOM ◽  
Phanit KOOMHIN

The Morris water maze, which has been used for more than 30 years, is one of the most famous learning and memory tasks among animals. This method is robust and reliable, and it can be carried out anywhere with little effort. Nowadays, there are many companies creating analysis software to easily analyze the Morris water maze results. However, these softwares are costly and may be difficult for researchers in developing countries especially with limited research funds. Only escape latency and time spent in the target quadrant can be manually obtained after video review. To resolve this problem and to extend the ability to detect learning and memory impairment in the Morris water maze, we provide a novel low-cost analysis method using common office tools combined with ImageJ software to analyze learning and memory impairment in rat or mouse models. In this study, we used the 2-vessel occlusion (2VO) rats and sham-operated control rats as learning and memory deficit rats and normal rats, respectively. Taken together, travel distance, swimming speed, and swimming traces can be acquired from this method, which will help researchers to investigate further impairment of learning and memory in animal models.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Guoyuan Sui ◽  
Lianqun Jia ◽  
Nan Song ◽  
Dongyu Min ◽  
Si Chen ◽  
...  

Abstract Background A high-fat diet can affect lipid metabolism and trigger cardiovascular diseases. A growing body of studies has revealed the HDL-bound miRNA profiles in familial hypercholesterolaemia; in sharp contrast, relevant studies on high-fat diet-induced dyslipidaemia are lacking. In the current study, HDL-bound miRNAs altered by a high-fat diet were explored to offer some clues for elucidating their effects on the pathogenesis of dyslipidaemia. Methods Six pigs were randomly divided into two groups of three pigs each, namely, the high-fat diet and the balanced diet groups, which were fed a high-fat diet and balanced diet separately for six months. HDL was separated from plasma, which was followed by dissociation of the miRNA bound to HDL. miRNA sequencing of the isolated miRNA was performed to identify the differential expression profiles between the two groups, which was validated by real-time PCR. TargetScan, miRDB, and miRWalk were used for the prediction of genes targeted by the differential miRNAs. Results Compared with the balanced diet group, the high-fat diet group had significantly higher levels of TG, TC, LDL-C and HDL-C at six months. miRNA sequencing revealed 6 upregulated and 14 downregulated HDL-bound miRNAs in the high-fat diet group compared to the balanced diet group, which was validated by real-time PCR. GO enrichment analysis showed that dysregulated miRNAs in the high-fat diet group were associated with the positive regulation of lipid metabolic processes, positive regulation of lipid biosynthetic processes, and positive regulation of Ras protein signal transduction. Insulin resistance and the Ras signalling pathway were enriched in the KEGG pathway enrichment analysis. Conclusions Twenty HDL-bound miRNAs are significantly dysregulated in high-fat diet-induced dyslipidaemia. This study presents an analysis of a new set of HDL-bound miRNAs that are altered by a high-fat diet and offers some valuable clues for novel mechanistic insights into high-fat diet-induced dyslipidaemia. Further functional verification study using a larger sample size will be required.


1997 ◽  
Vol 272 (1) ◽  
pp. E147-E154 ◽  
Author(s):  
A. P. Rocchini ◽  
P. Marker ◽  
T. Cervenka

The current study evaluated both the time course of insulin resistance associated with feeding dogs a high-fat diet and the relationship between the development of insulin resistance and the increase in blood pressure that also occurs. Twelve adult mongrel dogs were chronically instrumented and randomly assigned to either a control diet group (n = 4) or a high-fat diet group (n = 8). Insulin resistance was assessed by a weekly, single-dose (2 mU.kg-1.min-1) euglycemic-hyperinsulinemic clamp on all dogs. Feeding dogs a high-fat diet was associated with a 3.7 +/- 0.5 kg increase in body weight, a 20 +/- 4 mmHg increase in mean blood pressure, a reduction in insulin-mediated glucose uptake [(in mumol-kg-1.min-1) decreasing from 72 +/- 6 before to 49 +/- 7 at 1 wk, 29 +/- 3 at 3 wk, and 30 +/- 2 at 6 wk of the high-fat diet, P < 0.01]. and a reduced insulin-mediated increase in cardiac output. In eight dogs (4 high fat and 4 control), the dose-response relationship of insulin-induced glucose uptake also was studied. The whole body glucose uptake dose-response curve was shifted to the right, and the rate of maximal whole body glucose uptake was significantly decreased (P < 0.001). Finally, we observed a direct relationship between the high-fat diet-induced weekly increase in mean arterial pressure and the degree to which insulin resistance developed. In summary, the current study documents that feeding dogs a high-fat diet causes the rapid development of insulin resistance that is the result of both a reduced sensitivity and a reduced responsiveness to insulin.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Hyeon Yong Lee ◽  
Jin Bae Weon ◽  
Youn Sik Jung ◽  
Nam Young Kim ◽  
Myong Ki Kim ◽  
...  

Aronia melanocarpa(A. melanocarpa)berriesare a fruit with a marked antioxidant effect. The objective of this study was to confirm the effect ofA. melanocarpa berriesextract against scopolamine-induced memory impairment in mice using the Morris water maze and passive avoidance test. Moreover, we determined a possible mechanism of the cognitive-enhancing effect involving AChE activity and BDNF and p-CREB expression in the hippocampus of mice.A. melanocarpa berriesextract attenuated the learning and memory impairment induced by scopolamine in the Morris water maze (79.3 ± 0.8 s of 200 mg/kg and 64.4 ± 10.7 s of 400 mg/kg on day 4) and passive avoidance tests (46.0 ± 41.1 s of 200 mg/kg and 25.6 ± 18.7 s of 400 mg/kg).A. melanocarpa berriesextract reduced the acetylcholinesterase level in the hippocampus of scopolamine-injected mice and increased BDNF and p-CREB expression in the hippocampus. The major compound, cyanidin-3-O-galactoside, also reversed memory impairment. These results showed thatA. melanocarpa berriesextract improved memory impairment by inhibiting AChE and increasing BDNF and p-CREB expression, and cyanidin-3-O-galactoside may be responsible for the effect ofA. melanocarpa berriesextract.


2021 ◽  
Vol 19 ◽  
Author(s):  
Tingting Pi ◽  
Guangping Lang ◽  
Bo Liu ◽  
Jingshan Shi

Background: High methionine-diet (HMD) causes Alzheimer's disease (AD)-like symptoms. Previous studies have shown that Dendrobium nobile Lindle. alkaloids (DNLA) had potential benefits for AD. Object: Whether DNLA can improve AD-like symptoms induced by HMD is to be explored. Method: Mice were fed with 2% HMD diet for 11 weeks, the DNLA20 control group (20 mg/kg), DNLA10 group (10 mg/kg), and DNLA20 group (20 mg/kg) were administrated with DNLA for 3 months. Morris water maze test was used to detect learning and memory ability. Neuron damage was evaluated by HE and Nissl stainings. Levels of homocysteine (Hcy), beta-amyloid 1-42 (Aβ1-42), S-adenosine methionine (SAM), and S-adenosine homocysteine (SAH) were detected by ELISA. Immunofluorescence and western blotting (WB) were used to determine the expression of proteins. CPG island methylation. Results: Morris water maze test revealed that DNLA improved learning and memory dysfunction. HE, Nissl, and immunofluorescence stainings showed that DNLA alleviated neuron damage and reduced the 5-methylcytosine (5-mC), Aβ1-40, and Aβ1-42 levels. DNLA also decreased the levels of Hcy and Aβ1-42 in the serum, along with decreased SAM/SAH levels in the liver tissue. WB results showed that DNLA down-regulated the expression of the amyloid-precursor protein (APP), presenilin-1 (PS1), beta-secretase-1 (BACE1), DNA methyltransferase1 (DNMT1), Aβ1-40, and Aβ1-42 proteins. DNLA also up-regulated the expression of the protein of insulin-degrading enzyme (IDE), neprilysin (NEP), DNMT3a, and DNMT3b. Meanwhile, DNLA increased CPG island methylation levels of APP and BACE1 genes. Conclusions: DNLA alleviated AD-like symptoms induced by HMD via the DNA methylation pathway.


Author(s):  
Ch Venkataramaiah ◽  
G Swathi ◽  
W Rajendra

 The morris water maze (MWM) was developed by morris as a device to investigate spatial learning and memory in laboratory rats. MWM has become one of the most frequently used laboratory tools in behavioral neuroscience. The MWM task has been often used in the validation of rodent models for neurocognitive disorders (e.g., Parkinson, Alzheimer, Epilepsy, and Schizophrenia), and the evaluation of possible neurocognitive treatments. It is also being used to assess the properties of established potential antipsychotics in animal models of Schizophrenia. The MWM task requires rats to find a hidden platform in a large, circular pool of water that is colored opaque with powdered non-fat milk (or) non-toxic tempera paint where they must swim to the hidden platform. Because they are in the opaque water, the animals cannot see the platform and cannot rely on scent to find the escape route. Instead, they must rely on extra-maze cues. The behavior of rat can be evaluated by analyzing the different parameters such as escape latency, swim speed, and path length, and probe trail. The purpose of this review is to briefly describe procedural aspects, interpretational difficulties of data and advantages of MWM. This paradigm has become a benchmark test for learning and memory difficulties in animal models and preclinical research in general.


2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Qishu Zhou ◽  
Chunyu Liang ◽  
Yafei Li ◽  
Yi Yan

Objective  To investigate the effect of one-time high-intensity intermittent exercise in white fat autophagy in obese rats and provide a theoretical basis of the molecular mechanism of exercise fat loss. Methods  Eighteen male 3-weeks-old rats were selected and divided into control group fed with normal diet (C), high-fat diet group fed with high fat diet (H). After 16 weeks, there were twelve obesity rats that divided into diet group (HS) and exercise group (HE). The other six control group rats of 19 weeks age were used as the standard (CS group). OE group did the high intensity intermittent exercise once. The CS group and the CS group were kept quietly. Three groups were taken subcutaneous white adipose tissue(S) and epididymal white adipose tissue (E) immediately after exercise. Mensurate the expression of LC3 gene in the tissue using the fluorescent quantitative PCR. Results 1. The expression of LC3 mRNA from white fat tissue was different to the tissues, which the expression of epididymal white adipose tissue of each group was higher than that in subcutaneous white adipose tissue (P <0.01). 2. Compared with CS group, the expression of epididymal white fat adipose tissue LC3 mRNA decreased (P<0.01) and the expression of the subcutaneous white adipose tissue increased from HS group (P <0.05). 3. Compared with OS group, the expression of epididymal white fat adipose tissue LC3 mRNA decreased (P<0.05) and the expression of subcutaneous white adipose tissue decreased from OS group. Conclusions The expression of LC3mRNA in epididymal white fat adipose tissue of rats was significantly higher than that of subcutaneous white fat. The changes of LC3mRNA expression of adipose tissue caused by high-fat diet have tissue differences. One-time high-intensity intermittent exercise can reduce the expression of LC3mRNA in fat tissue of obese rats. Its regulatory mechanism needs to be further studied.


Author(s):  
Diego Castro Musial ◽  
Tânia Cristina Alexandrino Becker ◽  
Aline Paula Isolani ◽  
Lívia Bracht ◽  
Ana Carla Broetto Biazon

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