Animal models of social stress: effects on behavior and brain neurochemical systems – Blanchard et al. 2001
This paper mainly focused on the effects of social stress, specifically victory and defeat amongst dominant and subordinate conspecifics. This paper didn’t really relate to reptiles so this post was shorter than most and only includes what I thought was most useful for my own work.
- Different types of stressful events can sometimes produce qualitatively different patterns of effects in both behaviour and physiolology. For example an animal that is repeatedly socially defeated versus an animal that repeatedly had electric foot shocks produce opposite effects on systolic blood pressure and mean arterial blood pressure.
- Social stress occurs for solitary species as well, for example spacing between individuals is based on avoidant behaviours that are focused on other conspecifics, and agonistic interactions can occur as a result of avoidance being incomplete or slow.
- The duration of social stress, whether it is a single occurrence, intermittent or chronic can affect the interactions that follow. These interactions can range from affiliative to agonistic and can vary in intensity.
- In general when animals are grouped together, it seems that the provision of a larger and more natural habitat can produce higher levels of fighting. There was only one reference for this sentence in the paper, but in my head, the larger and more natural the habitat, the less chance of fighting because avoidance is much easier and if the area is large enough then I’m assuming resources may also be plenty? But maybe its because larger more natural areas create more territorial conspecifics?
- We can manipulate agnostic behaviour by setting up social groups that are fixed for a certain duration and then mixing them up to create social instability or by adding in conspecifics that we know are highly aggressive or submissive.
- This is interesting – For rats, social grouping appears to be more stressful for males while isolation is more stressful for females
- When referring to physiological markers, the prototypical stress marker is the activity of the hypothalamic-pituitary-adrenal axis (HPA), and it is typically measured as cortisol or corticosterone in plasma, saliva and feces. Another measure for stress could be the weight of relevant organs such as the adrenal glands or observing weight gain/loss during stressful time periods.
- Drug administration – Subordinate rats are known to take an increased dose of drugs through self administration, while social instability is known to decrease the self administration of drugs like amphetamines for example when males cohabit with females. Wonder if we can look at the same with snakes in terms of preference in body temperature.
- Odour preferences – subordinate mice prefer the odour of unfamiliar females but when dealing with the odours of dominant mice, subordinates prefer the scent of a familiar dominant rather than unknown dominant. Maybe we could see something similar with the social assay in the snakes since we used scents for that? Maybe certain personality types prefer the scented shelter while others don’t?
Al3xandria 