Cosmic ray induced radiation contains heavy-ions such as 56Fe which could have detrimental effects on the cognition of humans. Astronauts exposed to such radiation may experience long term health risks while on timely space missions. New research presents the effects of cosmic radiation on the cognition of mice, which helps us identify potential risks for space travelers.
Researchers assessed cognitive functioning in mice exposed to 56Fe radiation at various doses. At two-weeks, a degradation of object recognition and network stability was found at the lowest (0.1 Gy) and highest (0.4 Gy) irradiation doses. However, this was not apparent from the intermediate dose (0.2 Gy).
This study shows how exposure to 56Fe ions at particular doses has a direct effect on object recognition in mice. Astronauts in space are likely to be subject to the lowest irradiation dose, and so, could be at risk of cognitive impairment.
Cold tolerance in Arctic bacterium
Cyanobacteria have the ability to thrive in extreme environmental conditions, such as extreme cold where they are key primary producers. As many lineages survive such harsh conditions, it is uncertain how they do and whether this is the result of an evolutionary adaption.
The Cyanobacterium Phormidesmis priestleyi can be found in the Arctic, Antarctic and cold alpine habitats. In this study, the sequencing of a P. priestleyi BC1401 isolate from the Greenland Ice Sheet has been undertaken. Researchers examined the specific genes associated with cold shock response and extracellular polymeric substance generation.
The results show that these substances may enable cyanobacteria to withstand the effects of extreme cold. However, this feature is found throughout the phylum and is not a unique characteristic of P. prisetleyi. It is implied that the key to understanding why this extremophile is so successful in cold systems may be found in its regulation of the extracellular polymeric substances.
Why are some dogs more prone to stress, separation anxiety and aggression than others? These behaviors can cause a burden in our society, though let’s not be quick to point the finger at the dogs themselves, as the answer may be down to canine genomic expression.
Hundreds of dogs from a variety of breeds were analyzed using genome-wide association (GWA) mapping for fear and aggression traits. Key associations were discovered between particular genes and specific behaviors. The results showed that known loci variants IGF1 and HMGA2 (for small body size) were associated with separation anxiety, touch sensitivity, owner directed aggression and dog rivalry. Two loci between GNAT3 and CD36 (on chr18, near IGSF1 on ChrX) correlated with touch-sensitivity, non-social fear, as well as aggressive behavior towards unfamiliar dogs and humans.
In dogs, these loci are known to correlate with particular morphologies, and to be highly evolutionarily-selected. CD36 was found to be enriched in regions of the amygdala and hypothalamus, while other genes were well expressed in the amygdala to hypothalamic-pituitary-adrenal axis. It is implied that at these loci, the variants of reduced fear may be an after effect of canine domestication.