Sporadic dementia of Alzheimer's type (SDAT) pathogenesis has not been revealed completely due to the difficulty in creating an appropriate animal model. The purpose of this study was to investigate the effect of single-dose intraperitoneal (IP) induction of streptozotocin (STZ) and lipopolysaccharide (LPS) on the β-amyloid levels and the brain function of experimental rats. Eighteen rats were divided into three groups i.e. control, TRE1 (STZ 60 mg.kg-1 BW + LPS 3 mg.kg-1 BW), and TRE2 (STZ 30 mg.kg-1 BW + LPS 1.5 mg.kg-1 BW). The substances were administered in a single dose. Behavioral tests were started at day-30 after injection, we performed Morris water maze (MWM) and novel object recognition (NOR) tests. Afterward, we measured whole brain and serum β-amyloid levels, as one of the biomarkers of Alzheimer's Disease (AD), using the ELISA method. In MWM tests, the escape latency and time spent in the target quadrant of treatment groups were significantly higher than those in control at the day-5 MWM test and probe trial. The rats in treatment groups have negative discrimination indexes in NOR tasks, indicating that the rats could not remember the familiar object. Intraperitoneal STZ and LPS significantly increase soluble brain β-amyloid levels of treatment groups than those in the control group. In conclusion, the treatment of STZ (60 mg.kg-1 BW) and LPS (3 mg.kg-1 BW) indicated spatial and recognition memory impairment, along with an increase of brain soluble β-amyloid level in rats.

No abstract

Several physiological alterations that arise in response to hypoxemia conditions when diving are intended to protect oxygen-sensitive organs from the hypoxic condition. Hippocampus, known for its central function in memory formation, is sensitive to hypoxic conditions. This research aimed to study the effect of voluntary diving exercise (VDE) on the hippocampus-dependent learning performance of rats. Rats were divided into control and diving groups, with swim and voluntary diving exercises every day for 60 days, respectively. Observation of memory consolidation was carried out using Morris Water Maze (MWM) and Novel Object Recognition (NOR) tests. In the MWM test, the escape latencies in the diving group were shorter than those in the control group. Consistent results were obtained in the MWM probe trial which the time spent in the target quadrant was significantly longer in the diving group. Moreover, the diving group spent more time exploring the novel object in the NOR test. Based on the results, we can conclude that 60 days VDE significantly improves hippocampus-dependent learning capacity in trained rats.

Excessive consumption of fatty foods can lead to hyperlipidemia, which is often coupled with hypertriglyceridemia (HTG), a condition where blood plasma triglyceride (TG) levels elevated beyond normal levels. This condition may disturb physiological functions of the body, such as reproductive functions, and other physiological imbalances leading to chronic stress and depression. Ulva lactuca is a potential natural treatment for HTG, as it contains various nutrients to aid physiological functions. This seaweed also has high levels of Cd, which can increase depression. Therefore, research on the potential benefits of U. lactuca should be followed by an investigation of its health risks. This research aimed to examine the effects of HTG and treatment with U. lactuca on reproduction and depressive-like behavior of male Wistar rats (Rattus norvegicus Berkenhout, 1769). The data collected in this research include body weight, serum TG concentration, gonadosomatic index (GSI), serum testosterone concentration using competitive ELISA, and depressive-like behaviors assessed using the Forced Swim Test (FST) and Open Field Test (OFT). Data were analyzed using One-Way ANOVA followed by DMRT, independent- and paired-samples t-test, and Kruskal-Wallis H test with a significance value of α=0.05. Body weight, serum TG and testosterone concentration, GSI, and depressive-like behaviors were increased by the HTG condition. Ulva lactuca at the1500 mg/kg BW/day did not significantly affect body weight, testosterone concentration, and depressive-like behaviors of HTG rats. Meanwhile, this treatment significantly increased the GSI and depressive-like behaviors of healthy rats. These results suggest that Ulva lactuca treatment not only enhances gonad growth and development but also increases depressive-like behaviors.