No Effects of Meteorological Factors on the SARS-CoV-2 Infection Fatality Rate

Objective Previous studies have shown that meteorological factors may increase COVID-19 mortality,likely due to the increased transmission of the virus.However,this could also be related to an increased infection fatality rate(IFR).We investigated the association between meteorological factors(temperature,humidity,solar irradiance,pressure,wind,precipitation,cloud coverage)and IFR across Spanish provinces(n=52)during the first wave of the pandemic(weeks 10–16 of 2020).Methods We estimated IFR as excess deaths(the gap between observed and expected deaths,considering COVID-19-unrelated deaths prevented by lockdown measures)divided by the number of infections(SARS-CoV-2 seropositive individuals plus excess deaths)and conducted Spearman correlations between meteorological factors and IFR across the provinces.Results We estimated 2,418,250 infections and 43,237 deaths.The IFR was 0.03%in<50-year-old,0.22%in 50–59-year-old,0.9%in 60–69-year-old,3.3%in 70–79-year-old,12.6%in 80–89-year-old,and26.5%in≥90-year-old.We did not find statistically significant relationships between meteorological factors and adjusted IFR.However,we found strong relationships between low temperature and unadjusted IFR,likely due to Spain’s colder provinces’aging population.Conclusion The association between meteorological factors and adjusted COVID-19 IFR is unclear.Neglecting age differences or ignoring COVID-19-unrelated deaths may severely bias COVID-19 epidemiological analyses.

Scientific Interest of Social Behaviour in Animal Models of Human Diseases

The overview shows that the scientific interest in social behaviour in mice has exponentially grown in the last two decades in parallel with advances in biotechnology and the emergence of genetically engineered mice. Most of the studies are psychopharmacological or look for the neurochemical bases of social behaviour and its alterations. However, the rol of social behaviour per se is increasing mainly in those research works aimed to model neuropsychiatric and neurode-generative diseases. In fact, at the translational level, the study of social behaviour in murine models is relevant because changes in social behaviour are present in most neuropsychiatric and neurodegenerative disorders as well as in other diseases that, directly or indirectly, affect the sphere of social relationships. The consideration of social behaviour in the experimental design of basic and translational research works using murine models may improve the predictive validity of new preventive and/or therapeutic strategies. The present work provides conceptual description of social behaviour in mice, the tests used to measure it and analyzes its increasing interest, mostly in the area of neuroscience. It reviews the 821 scientific studies (in English) included in the MEDLINE database from 1930 to December 2012. Keywords used for the search where those related to the different kinds of social behaviour (spontaneous or induced) in mice and took into account the diversity of experimental paradigms (dyads, groups, parental relationships, isolation) and the wide spectrum of behavioural tests available.

Genetic Rat Models of Schizophrenia-Relevant Symptoms

It is recognized that developing valid animal models is essential for the research on the neurobiological mechanisms of (and treatments for) psychiatric disorders, even when these are as complex as schizophrenia. To be considered a valid analogue of the disorder, a given model should present good face validity (i.e. similarity of symptoms), good predictive validity (i.e. similarity of treatment effects and potential for discovering novel treatments) and enough construct validity (i.e. the model should help discover neurobiological mechanisms underlying the disorder or some relevant symptoms). The complexity of symptoms (positive, negative and cognitive) of schizophrenia makes it a very difficult task for a model to mimic all the main features of the disorder, but some rodent (mouse and rat) models have behavioural and even neurobiological phenotype characteristics resembling positive-like symptoms, cognitive symptoms and some neurochemical features of schizophrenia. As several recent works have already reviewed the main behavioural and developmental models, as well as the most used drug-induced, lesion-induced and genetic mouse models, the present review focuses on describing the most relevant genetically-based rat models of schizophrenia-relevant symptoms. Thus, we discuss several selective breeding programs leading to rat lines/strains which present impaired prepulse inhibition (PPI) of the acoustic startle response and (in some cases) latent inhibition deficits (both of which may be considered as endophenotypes of schizophrenia related with pre-attentive processes and attention, respectively), as well as other schizophrenia-relevant symptoms (e.g. learning deficits). Evidence is presented for the effects of genetic background on PPI (and other symptoms/phenotypes), as well as for environmental influences on genetic predisposition to enhanced apomorphine (mixed dopamine receptor agonist) effects. Some of the described rat models appear to present face validity and, to a certain extent, construct validity. While efforts should be made to evaluate the predictive validity of these genetic rat models, we propose that they have the advantage (over mouse knockouts, for example) of better representing “normal” genetic, neurobiological and phenotype variation, thus allowing the study of associations among them by means of genetic mapping or gene expression studies.