Monday, September 3, 2007

Pheromones in Animals accepted, but Pheromones in Humans??

This is really Interesting!!!
Recent research at Howard Hughes Meidcal Institute has shown that Trpc2, an Ion channel expressed in Vomensoral Neurons in mice is responsible Sex-Determination.
Male mice that are deficient in this ion channel Trpc2 had impairement in sex-determination and male-male aggression. The focus of this study was on female mice. Mutant Trpc2 mice showed a reduction in female specific behaviour like lactation and maternal aggression.The most interesting feature observed was these mutant females showed unique characteristics of male sexual courtship behaviours like pelvic thrusts.The same behavorial phenotype was observed when Vomensoral Organs were surgically removed but the oestrous cycles and sex-hormones levels were not disrupted.
This showed that VNO(Vomensoral Organ) mediated pheromones input in Wild Type females represses male behaviour and increases female specific behaviour.
This study also proved another point and that there were functional neuronal circuits for male specific behaviours in normal female mouse brain.

This gets me to a very interesting question that has always been a controversy
Wether Human Olfactory Signals exist or not??
Though much has been talked and written about, has any Human Pheromone been isolated and has it's activity been demonstrated or not is the biggest question I have.Can I get an explanation for this.
Looking for your comments

2 comments:

srivatsava said...

chemse.oxfordjournals.org/cgi/content/full/30/suppl_1/i321

furquan said...

Regarding olfactory signalling in humans I can say that: Vomeronasal organ during the course of evolution have become less active in animals who donot use sense of smell as their primary sense, as in apes, bats (which communicate through frequency) and also humans. Therefore in adult humans there is no profound connection between the brain and the regressed Vomeronasal organ.

And regarding isolation of human pheromones: there have been studies done on synchronization of menstrual cycles among women based on unconscious odor cues where the scientists have suggested "possibility of pheromones in humans", but there has been no such claim made about "human pheromones". You can find such claims in bogus advertisments trying to sell their "arousal perfumes".

BUT.....

Still there is some part played by odor recognition in humans. response of homosexual men towards odors involving sexual arousal is similar to the response of heterosexual women towards the same odor. Hans Berglund (http://www.pnas.org/cgi/content/abstract/0600331103v1?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=ivanka&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT) also found that homosexual women were not as responsive to male identified odors but their response to female cues was similar to heterosexual males.

Thats what I can say.