Methodological Characteristics of the Use of the Morris Water Maze for Assessment of Cognitive Functions in Animals

Impact of Chronic Oral Administration of Gold Nanoparticles on Cognitive Abilities of Mice

The influence of gold nanoparticles after their prolonged oral administration to mice (during pregnancy and lactation) on spatial memory and anxiety levels in offspring was investigated. Offspring were tested in the Morris water maze and in the elevated Plus-maze. The average specific mass content of gold which crossed the blood-brain barrier was measured using neutron activation analysis and constituted 3.8 ng/g for females and 1.1 ng/g for offspring. Experimental offspring showed no differences in spatial orientation and memory compared to the control, while their anxiety levels increased. Gold nanoparticles influenced the emotional state of mice exposed to nanoparticles during prenatal and early postnatal development, but not their cognitive abilities.

Does Nanosilver Have a Pronounced Toxic Effect on Humans?

Due to the development of high-tech industries, the modern world is characterized by the increased production and consumption of nanoparticles (NPs) and nanomaterials. Among produced metal nanoparticles, silver nanoparticles are widely used in everyday life products, cosmetics, and medicine. It has already been established that, in nanoscale form, many even inert materials become toxic. Therefore, the study of the toxicity of various substances in nanoscale form is an urgent scientific task. There is now a body of experience on the toxic effect of AgNPs. In the present review, the most well-known results obtained over the 2009–2021 period, including the own performance on the toxicity of silver NPs, are collected and analyzed. Along with the data reporting a certain level of toxicity of silver NPs, experiments that did not reveal any obvious toxicity of nanosized forms of silver are discussed. According to the performed studies, the toxicity of silver NPs is often caused not by NPs themselves but by silver ions, compounds used for nanoparticle stabilization, and other reasons. Based on the analysis of the collected data, it can be concluded that at actual levels of silver NPs used in everyday life, workplace, and medicine, they will not have strong toxic effects on a healthy adult body.

Swimming in the maze: An overview of maze apparatuses and protocols to assess zebrafish behavior

Most preclinical behavioral assays use rodents as model animals, leaving room for species-specific biases that could be avoided by an expanded cross-species approach. In this context, zebrafish emerges as an alternative model organism to study neurobiological mechanisms of anxiety, preference, learning, and memory, as well as other phenotypes with relevance to neuropsychiatric disorders. In recent years, several zebrafish studies using different types of mazes have been published. However, the protocols and apparatuses' shapes and dimensions vary widely in the literature. This variation may puzzle researchers attempting to implement maze behavioral assays and challenges the reproducibility across institutions. This review aims to provide an overview of the behavioral paradigms assessed in different types of mazes in zebrafish reported in the last couple of decades. Also, this review aims to contribute to a better characterization of multi-behavioral assessment in zebrafish.