New scientific article from the rat ticklers - Ticklish rats more emotional!

[P_Bustleton]

Behav Brain Res. 2012 Apr 1;229(1):138-44. Epub 2012 Jan 13. http://www.ncbi.nlm.nih.gov/pubmed/22266925

TL;DR version: Rats stop playing with each other when they believe they are in the presence of a predator, like a cat. Ticklish rats were more affected by the smell of a cat than non-ticklish rats. Whereas non-ticklish rats went back to playing with each other after just one day, the ticklish rats took much longer to start playing again.

The authors hypothesize that ticklish animals have "enhanced associative-learning abilities" which lead to "stronger negative context conditioning." Applied to people, this would mean that ticklish people can learn better in certain ways, but they are also more prone to be affected emotionally by outside disturbances. The authors don't seem to go that far, and merely state that breeding for one behavior (ticklishness) can lead to changes in another behavior (emotional learning).

Abstract:

Ultrasonic vocalizations (USVs) are emitted by rodents and can signal either negative or positive affective states in social and nonsocial contexts. Our recent work has utilized selective breeding based upon the emission of 50kHz USVs in response to standard cross species hand play-namely experimenters 'tickling' rats. Previous work has shown that high-tickle responsive animals (i.e., rats emitting abundant 50kHz USVs) are gregarious and express enhanced positive emotional behaviors relative to animals exhibiting low 50kHz USVs. The present study extends this work by examining the developmental profile of play behavior and the suppression of play behavior by predator (cat) odor in juvenile high-line and low-line animals. Results support dissociations in key play measures between these groups, with high-line animals emitting more dorsal contacts during play and low-line animals emitting more pinning behavior. For cat-odor induced play suppression, we found that high-line animals exhibit elevated suppression of play for a prolonged period compared to low-line rats. In contrast, low-line animals returned to normal levels of play just 1 day post-predator odor experience. These findings support the idea that emotional arousal may differ between these selectively bred groups, and extends previous work by demonstrating a possible influence of altered emotional learning and conditioning in these phenotypically different animals. One possibility is that high-line animals exhibit enhanced associative learning abilities leading to stronger negative contextual conditioning. These findings suggest that selection for positive or negative social-emotional phenotypes may also segregate genes that control emotional learning abilities in unanticipated ways.

 

[rhiannon]

Who in the world PAYS for studies like that!?

 

[milagros317]

I'd rather study women than rats. 😛

 

[GEORGIATKLER]

Who builds all the little couches on which the rats recline while "shooting the cheese" about their emotions?? 😉 I wonder what other traits were also increased/decreased in response to the cat odor? How critical is being emotional to rodents' survival? It seems the less ticklish rats recovered faster from the cat odor, which would be a good thing. Maybe the survival instinct overrides the social order for the individual rats.