Friday, 3 August 2007

The DNA of Dance

AVPR1a and SLC6A4 Gene Polymorphisms Are Associated with Creative Dance Performance (research article)
By: Rachel Bachner-Melman, Christian Dina, Ada H. Zohar, Naama Constantini, Elad Lerer, Sarah Hoch, Sarah Sella, Lubov Nemanov, Inga Gritsenko, Pesach Lichtenberg, Roni Granot, Richard P. Ebstein
Published: September 30, 2005
“With the creation of the universe, the dance too came into being, which signifies the union of the elements. The round dance of the stars, the constellation of planets in relation to the fixed stars, the beautiful order and harmony in all its movements, is a mirror of the original dance at the time of creation.” - Lucian of Samosata (~125 to 180 A.D.), On Dance (De Saltatione)

Dancing, integrally related to music, likely has its origins close to the birth of Homo sapiens. The authors hypothesized that there are differences in aptitude, propensity, and need for dancing that may be based on differences in common genetic polymorphisms. Identifying such differences may lead to an understanding of the neurobiological basis of dancing.

Variants of the serotonin transporter and the arginine vasopressin receptor 1a genes were examined in performing dancers, elite athletes, and nonathletes/nondancers. The serotonin transporter regulates the level of serotonin, a brain transmitter that contributes to spiritual experience. The vasopressin receptor has been shown in many animal studies to modulate social communication and affiliative behaviors. Notably, dancers scored high on the Tellegen Absorption Scale, a correlate of spirituality, and the Reward Dependence factor in Cloninger's Tridimensional Personality Questionnaire, a measure of empathy, social communication, and need for social contact. Significant differences were observed in allele frequencies for both genes when dancers were compared to athletes as well as to nondancers/nonathletes. These two genes were also associated with scores on the Tellegen Absorption Scale and Tridimensional Personality Questionnaire Reward Dependence, suggesting that the association between these genes and dance is mediated by personality factors reflecting the social communication, courtship, and spiritual facets of the dancing phenotype.

Dance, an art form closely allied to music, has been little studied from the neuroscience or genetic perspective, despite its significance in all cultures throughout the ages. Dance, like music, is an activity dating to prehistoric times that is sometimes a sacred ritual, sometimes a form of communication, and sometimes an important social and courtship activity; finally, dance is an art form that exists in every culture and manifests diverse paths [1]. Dance, as an expressive art form, is often considered inherently creative, especially when compared with a “nonartistic” domain. It is also a cultural form that results from creative processes that manipulate human bodies in space and time (“embodiment”). In many ways, dance is also a part of music, to which it is integrally related. Finally, professional dancers possess an exceptional talent, and as noted by Kalbfleisch [2], “Exceptional talent is the result of interactions between goal-directed behavior and nonvolitional perceptual processes in the brain that have yet to be fully characterized and understood by the fields of psychology and cognitive neuroscience.”

Dance may appear to be an unusual phenotype for human molecular genetics studies, but it is no more so than two closely related phenotypes, music [3] and athletic performance [4−6], that have both become subjects of molecular research. There is accumulating contemporary interest in the neuroscience of music [3,7−11] providing “proof of principle” that a widespread pursuit historically considered as part the human art and cultural heritage also has a solid basis in neuroscience, evolution, and genetics. Both music and athletic performance are complex phenotypes, the presentation of which is molded by environment and genes (and their interaction), especially in elite performers. A good example is absolute pitch, a relatively “clean” musical phenotype, of which the occurrence in approximately 20% of professional musicians is dependent not only on intrinsic ability but also on age of onset and intensity of musical training [11]. Similarly for athletic performance, evidence has accumulated over the past three decades for a strong genetic influence on human physical performance, with an emphasis on two sets of physical traits, cardiorespiratory and skeletal muscle function, that are particularly important for performance in a variety of sports [4]. A number of individual genetic variants associated with elite athletes have been provisionally identified, but there is little argument that elite athletes as well as elite musicians likely possess other characteristics related to personality and emotion that also contribute to their performance.

We suggest the notion that the “dance” phenotype is no more difficult to define than other complex human behavioral phenotypes (schizophrenia, attention deficit, personality, violence, and others) that have been shown to be both heritable and amenable to genetic analysis. Dancers fulfill a set of criteria with considerable face validity (similar in principle to the usual Diagnostic and Statistical Manual of Mental Disorders–style “symptom checklist” [12]) that both identifies and distinguishes one disorder from another. For example, the US Department of Labor suggests that the following qualities, inter alia, are required to be a professional dancer: flexibility, agility, coordination, grace, a sense of rhythm, a feeling for music, and a creative ability to express oneself through movement [13].

In our ongoing studies of the genetic basis of human personality [14−16], we have recruited currently performing dancers (n = 85) who train for at least 10 h per week, because we thought that a study of this group would help us understand why some individuals are endowed with creative and artistic abilities or inclinations. Toward this end, dancers were characterized using both psychosocial instruments and common genetic polymorphisms. Of particular interest are the Tridimensional Personality Questionnaire (TPQ) [17] and the Tellegen Absorption Scale (TAS) [18], which, respectively, measure aspects of social communication (TPQ Reward Dependence) and spirituality (TAS), personality facets important in the dance phenotype.

We investigated two polymorphic genes that we hypothesized to add to artistic creativity: the arginine vasopressin 1a receptor (AVPR1a) and the serotonin transporter (SLC6A4). The SLC6A4 long promoter allele is more efficient at the level of transcript, producing more transporter protein that presumably more effectively removes serotonin from the synapse [19]. Both common intron 2 VNTR repeats (10 and 12) enhance transcription [20], although individual repeat elements differ in their activity in embryonic stem cell models [21]. In lower vertebrates, the promoter region repeat elements of the AVPR1a receptor determine brain-specific expression patterns and are responsible for differences in patterns of social communication across species [22]. In humans, the functional significance of the promoter repeats remains to be elucidated, although association between these repeats and social communication in humans was recently suggested [14,23,24].

We considered that AVPR1a might contribute to the dance phenotype, reflecting this gene's role in affiliative, social, and courtship behaviors [25], activities that are vital in many kinds of human dancing. Dancing also taps into human spiritual resources as evidenced by the role of dancing in sacred rituals [1]; it has been shown that serotonin plays a role in human spiritual experiences [26]. Additionally, use of ecstasy, a serotonergic neurotoxin, at rave dances and dance clubs [27] further links serotonin to both dancing and states of altered consciousness, two phenomena also linked in the absence of drugs. Finally, many studies show that serotonin enhances the release of vasopressin in the brain [28], suggesting the notion that these two genes, AVPR1a and SLC6A4, are also likely to exhibit epistasis, or gene−gene interactions, in association studies that reflect their interaction at the level of individual neurons as well as on the plane of neurotransmitter pathways. Interestingly, serotonin and vasopressin interact in the hypothalamus to control communicative behavior [29].

NB: Please follow the link below to read the whole paper.

Source: Public Library of Science (Genetics)

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