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Personal view and explanation of this paper by first author Dr. Haoran Wang

Posted by PLOS_ONE_Group on 07 Apr 2008 at 12:27 GMT

This paper represents a milestone in animal emotion study

(Personal view and explanation of this paper by first author Dr. Haoran Wang)

We, for the first time, described positive and negative affects of male and female mice and provided lines of evidence showing that they can be indexed, respectively by ultrasonic vocalizations and squeaks in mice. This is a revolutionary development of previous work in rats.

Based on above finding, we, for the first time, established a new method of quantitatively measuring positive affect (emotion) in mice. This is essentially important, making many other related works possible and easier.

Sex is a basic life phenomenon. Emotion changes dramatically during sex. But it has been impossible to tell this change quantitatively. In this paper, I for the first time clearly described the dynamic change of affect (emotion) of both male and female mice using USVs and squeaks as indexes, respectively. This is particularly true in male mice. This is a breakthrough in science, to my knowledge.

In addition, we have studied 4 different genotypes of previously known reward associated genes (M2, M4, M5 muscarinic receptor and D2 dopamine receptor) knockout mice. We obtained beautiful results showing M2 and M5 are important ones in affecting mouse USVs and expression of positive affect (emotion). These are not only important findings, but also successful applications of screening 'emotion genes'.

Induction of USVs by amphetamine, a neurotransmitter dopamine activator, in male mice, but not in female mice and M5 knockout mice elucidated important part of the controlling mechanisms underlying the positive emotion of male mice, suggesting a difference of male and female mice and the requirement of M5 gene in the induction. This point is important because it probed the molecular basis and the difference between male and female rodents. There is a reference meaning for understanding humans' emotion.

I believe that our work in this paper has important theoretical and practical meaning in understanding the neural basis of emotion (probably motivation too) and the neural substance difference of males and females. The obtained knowledge can also be helpful in improving our methods of controlling emotion related diseases, 'increasing happiness' and 'decreasing sadness', improving our life quality, in particular here sexual life, as well as screening 'emotion genes'.

(This paper currently, April 4, 2008, has been reported by ScienceNOW, Science Daily and New Scientist websites).