Helplessness-like escape deficits of NIH-HS rats predict passive behavior in the forced swimming test:Relevance for the concurrent validity of rat models of depression

The genetically heterogeneous NIH-HS rat stock has been characterized by its response to anxiety- and fear-inducing situations, thus leading to the conclusion that they are a rather anxious and passive coping type of rats. Taking advantage of these profiles, and knowing that they show very poor performance in the two-way active (shuttle box) escape/avoidance task, we have tested NIH-HS rats (n = 80) in the forced swimming test (FST) as well as we have studied escape response deficits (i.e. response failures) of the same animals in the two-way shuttle box task. They were also tested for anxiety in the elevated zero-maze. The goal of such a study was that of investigating whether there are associations or relationships among helplessness-like or passive coping responses between both models of depression, i.e. the FST and the helplessness-like escape deficits in the shuttle box task. The results for the first time show associations among responses from both depression models and that selecting rats for displaying extreme (active or passive) responses in one of the models predict in a coherent manner (according to the hypothesis) their behaviour in the other model. These findings are discussed in the context of the concurrent validity of both models of depression as well as concerning the possible relevance of NIH-HS rats as a tool for future studies on this field.

Remote Working in the Period of the COVİD-19

Working remotely was an option for the employees before the Covid-19 pandemic.However,it's become a new working format and compulsory for the white collars to work at home.Even if it seems attractive at first look,the new format of working style actually has caused lots of problems especially on employees'mental health.The social life,private comfort zone,and working environment of the workers have mixed with each other and the equilibrium among them which gave certainty and predictability is totally broken now.Actually,the employees started to search for a new normal and balance in the pandemic.I am planning to focus on occupational stress that popped up in the pandemic with regard remote working.It is structured to focus on the problems which are the broken balance between work and family,the problem of workload and over-working,the future ambiguity about the career,and miscommunication,to analyze how these problems bring out mental health disorder with giving experiments done by other researchers.In the final part,I will try to give some suggestions on how to get over it or reduce it.

Behavioral animal models of depression

Depression is a chronic,recurring and potentially life-threatening illness that affects up to 20%of the population across the world.Despite its prevalence and considerable impact on human,little is known about its pathogenesis.One of the major reasons is the restricted availability of validated animal models due to the absence of consensus on the pathology and etiology of depression.Besides,some core symptoms such as depressed mood,feeling of worthlessness,and recurring thoughts of death or suicide,are impossible to be modeled on laboratory animals.Currently,the criteria for identifying animal models of depression rely on either of the 2 principles：actions of known antidepressants and responses to stress.This review mainly focuses on the most widely used animal models of depression,including learned helplessness,chronic mild stress,and social defeat paradigms.Also,the behavioral tests for screening antidepressants,such as forced swimming test and tail suspension test,are also discussed.The advantages and major drawbacks of each model are evaluated.In prospective,new techniques that will be beneficial for developing novel animal models or detecting depression are discussed.

Proteomic Analysis of the Hippocampus in Mouse Models of Trigeminal Neuralgia and Inescapable Shock-Induced Depression

To investigate the behavioral and biomolecular similarity between neuralgia and depression, a trigeminal neuralgia （TN） mouse model was established by constriction of the infraorbital nerve （CION） to mimic clinical trigeminal neuropathic pain. A mouse learned helplessness （LH） model was developed to investigate inescapable footshock-induced psychiatric disorders like depression in humans. Mass spectrometry was used to assess changes in the biomolecules and signaling pathways in the hip- pocampus from TN or LH mice. TN mice developed not only significant mechanical allodynia but also depressive- like behaviors （mainly behavioral despair） at 2 weeks after CION, similar to LH mice. MS analysis demonstrated common and distinctive protein changes in the hippocampus between groups. Many protein function families （such as cell-to-cell signaling and interaction, and cell assembly and organization,） and signaling pathways （e.g., the Huntington＇s disease pathway） were involved in chronic neuralgia and depression. Together, these results demonstrated that the LH and TN models both develop depressive-like behaviors, and revealed the involvement of manypsychiatric disorder-related biomolecules/pathways in the pathogenesis of TN and LH.