Acute environmental temperature variation affects brain protein expression, anxiety and explorative behavior in adult zebrafish.

This work investigates the
effect of a 4-day acute thermal treatment at 18 °C, 26 °C (control) and 34 °C
on the nervous system of adult zebrafish (Danio rerio) by a
multidisciplinary approach based on behavioural test and brain proteomic
analysis. The behavioural variations induced by the thermal treatment were
investigated by means of five different tests (novel tank diving, light and
dark preference, social preference, mirror biting, Y-Maze) which are paradigms
used on zebrafish for assessing anxiety, boldness, social preference,
aggressiveness, and explorative behaviour, respectively. Proteomic data
revealed that several proteins involved in energy metabolism, translation,
protein synthesis, folding and degradation, cytoskeleton organization and
synaptic vesiculation are differently regulated at the extreme temperatures. The results
showed increased anxiety-like behaviour and the down regulation of the
expression of proteins belonging to anxiety-related signalling pathways in
zebrafish at 18 °C compared to those at 26 °C and 34 °C. Moreover, the
treatment both at 18 °C and 34 °C alters the exploratory behaviour that appears
not to be modulated by past experiences suggesting an impairment of cognitive
abilities. The present study follows our previous works in which the effect of a
21-day chronic treatment at the same temperatures was investigated using the
same experimental design, allowing to compare the effect of acute and chronic
treatment on the nervous system of adult zebrafish.

本研究采用基于行为学测试与脑组织蛋白质组学分析的多学科研究方法，探究了18℃、26℃（对照组）及34℃下为期4天的急性热应激处理对成年斑马鱼（Danio rerio）神经系统的影响。研究通过五种经典行为学测试范式（新型水槽潜水实验、明暗偏好实验、社交偏好实验、镜像撕咬实验、Y型迷宫实验）分析热应激诱导的行为变化，上述测试分别用于评估斑马鱼的焦虑状态、大胆程度、社交偏好、攻击性与探索行为。蛋白质组学数据分析显示，在极端温度条件下，多种参与能量代谢、翻译过程、蛋白质合成、折叠与降解、细胞骨架组织以及突触囊泡形成的蛋白呈现差异表达调控。结果表明，与26℃及34℃处理组相比，18℃处理组的斑马鱼表现出显著的类焦虑行为，且焦虑相关信号通路相关蛋白的表达呈现下调趋势。此外，18℃与34℃的热应激处理均改变了斑马鱼的探索行为，且该行为变化不受过往经验调控，提示其认知能力受到损伤。本研究承接本团队此前的相关工作——此前团队采用相同实验设计，探究了相同温度梯度下为期21天的慢性热应激处理的影响，从而可实现急性与慢性热应激处理对成年斑马鱼神经系统影响的对比分析。