Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Biotech / Medical : Ligand (LGND) Breakout! -- Ignore unavailable to you. Want to Upgrade?

To: Flagrante Delictu who wrote (16581)	3/5/1998 9:10:00 PM
From: celeryroot.com	Read Replies (1) \| Respond to of 32384

Just checked mine is very large

To: Flagrante Delictu who wrote (16581)	3/5/1998 9:30:00 PM
From: Henry Niman	Respond to of 32384

The story came out a few days ago, but I have been able to find it. In general, the cochlea in gay females was found to be larger than straight females. The cochlea development is affected in utero by androgens. The speculation is that the androgen exposure programs the developing brain and babies exposed to high concentrations of androgens have "male" circuits established in their brain and the size of the developing cochlea is also affected (i's bigger). Thus the cochlea size is a marker for androgen exposure in utero and correlates with sexual orientation.

To: Flagrante Delictu who wrote (16581)	3/5/1998 10:14:00 PM
From: Henry Niman	Respond to of 32384

Here's the report:Study: Inner ears of lesbians show differences In this story: Exposure to male hormones before birth cited Test results considered tentative How test was conducted Related stories and sites March 2, 1998 Web posted at: 7:15 p.m. EST (0015 GMT) AUSTIN, Texas (CNN) -- The possibility that sexual orientation may be predisposed before birth gained new support in a research project being published this week that tested how women respond to sound. Scientists at the University of Texas, Austin, say they have found the first strong evidence of a physical difference between lesbians and straight women -- a finding that the inner ears of gay women work more like those of men. The study is to be published Tuesday in the Proceedings of the National Academy of Sciences. The origin of homosexuality has long been a matter of contention. Some believe it to be a matter of choice, but others -- including many gay people -- say it is not choice but biology. Previous research has found that two parts of the brain are different in gay and heterosexual men. Other studies have found that some genes differ between gay and straight men. Excess exposure to male hormones before birth cited The Texas scientists said they found the inner ears of lesbians have undergone "masculinization," probably from excess exposure to male hormones before birth. "Their auditory centers have been masculinized and the presumption is that so have the sites in the brain that direct sexual preference," said Dennis McFadden, the lead author of the study. It has yet to be proven, however, that there is a specific site in the brain that directs women to be lesbians, he said. Dr. Michael Bailey of Northwestern University said the research is "compelling" and may be "consistent with the biological origin of lesbianism." "The most likely interpretation," he said, "is that this represents some kind of effect of early hormones on the developing fetus." Test results considered tentative Bailey cautioned, however, that the research will not be accepted as valid until other scientists replicate the experiment. Sandra Witelson, an expert on brain anatomy and sexual orientation at McMaster University in Ontario, Canada, said the study supports the theory that lesbianism may be "related to early factors in brain development." Researchers stress that while science can measure trends among groups, it cannot predict sexual orientation for individuals, a caution that lesbian Laura Brown of Atlanta agrees with. The prospect that women might be tested and given hormones to control their sexuality is "frightening," says Brown. 119K / 9 sec. AIFF or WAV sound How test was conducted The inner ear difference between homosexual and heterosexual women was detected using a test that measures the function of the cochlea, a key sound amplifier in the inner ear, said McFadden, a professor of experimental psychology. The cochlea amplifier in women is more sensitive than that of men, giving women an increased ability to detect very soft sounds in a very quiet room. The test measures a very slight sound the cochlea makes when responding to a soft clicking sound. Females, with their more sensitive cochlea, respond more powerfully to this test than do men, said McFadden. This is true even among infants. To test for differences between the sexes, the researchers recruited more than 200 adults divided into four groups: homosexual women and men, and heterosexual women and men. Some from each of the four groups were later identified as bisexual. The sexual orientation of the subjects was determined by questionnaire. The results, McFadden said, indicated that lesbians had click-responses that were significantly weaker than those of heterosexual women. The signal was weaker still for all males, both gay and straight. Bisexual men and women were in the middle, although McFadden said there were not enough of these to draw firm conclusions. What is clear, he said, is that there is a dramatic difference in the development of the hearing systems of lesbians and heterosexual women. It also is known that development of the inner ear is affected before birth by androgens, a male hormone. Androgens, said McFadden, may also "alter the brain centers that produce sexual orientation." But he said researchers have yet to find a brain structure that determines sexual orientation in women. Senior Medical Correspondent Dan Rutz and The Associated Press contributed to this report.

To: Flagrante Delictu who wrote (16581)	3/5/1998 10:21:00 PM
From: Henry Niman	Read Replies (2) \| Respond to of 32384

Here's the abstract: Vol. 95, Issue 5, 2709-2713, March 3, 1998 Psychology-BS Comparison of the auditory systems of heterosexuals and homosexuals: Click-evoked otoacoustic emissions Dennis McFadden* and Edward G. Pasanen Department of Psychology and The Institute for Neuroscience, University of Texas, Austin, TX 78712 Edited by Ira J. Hirsh, Central Institute for the Deaf, St. Louis, MO, and approved December 12, 1997 (received for review September 4, 1997) Click-evoked otoacoustic emissions (CEOAEs) are echo-like waveforms emitted by normal-hearing cochleas in response to a brief transient. CEOAEs are known to be stronger in females than in males. In this experiment, the CEOAEs of homosexual and bisexual females were found to be intermediate to those of heterosexual females and heterosexual males. A parsimonious explanation is that the auditory systems of homosexual and bisexual females, and the brain structures responsible for their sexual orientation, have been partially masculinized by exposure to high levels of androgens prenatally. No difference in CEOAEs was observed between homosexual and heterosexual males. * To whom reprint requests should be addressed at: Department of Psychology, Mezes Hall 330, University of Texas, Austin, TX 78712. e-mail: mcfadden@psy.utexas.edu.

To: Flagrante Delictu who wrote (16581)	3/7/1998 8:41:00 AM
From: Henry Niman	Respond to of 32384

Here's the Reuters story on the Cochlea: Monday March 2 6:42 PM EST Inner Ear Link To Sexual Orientation NEW YORK (Reuters) -- The inner ears of lesbians and bisexual women show less ability to detect weak sounds compared with the inner ears of heterosexual women -- and this may stem from differences in fetal exposure to hormones, the same chemistry thought to influence sexual orientation, researchers say. Drs. Dennis McFadden and Edward Pasanen of the department of psychology and The Institute for Neuroscience at the University of Texas in Austin, speculate that "prenatal exposure to higher-than-normal levels of androgens (male sex hormones) in homosexual and bisexual females produced a partial masculinization of both their peripheral auditory systems and some brain structures involved with sexual orientation." "Our finding reveals the first physiological characteristic related to homosexuality in females," said McFadden in a statement issued by the Society for Neuroscience. "The study also indicates that the inner ear may be a valuable non-invasive window into events that occur during brain development and sexual differentiation," commented McFadden. The study, published in the current issue of the Proceedings of the National Academy of Sciences, focused on "click-evoked otoacoustic emissions" (CEOAEs) -- echo-like sounds produced by the inner ear in response to a weak click sound. In general, women tend to produce stronger CEOAEs than men -- and thus are generally better at hearing weak sounds than men. It is thought that this difference is because a female fetus is not usually exposed to high levels of male hormones. Further illustrating this point is the fact that women with a twin brother seem to have weaker CEOAEs compared with other women -- probably due to the influence of trace amounts of androgens circulating within a womb shared with a male fetus. Since fetal androgen exposure has also been linked to the development of homosexuality in women, the Texas researchers wondered if patterns of inner ear function might mirror patterns of sexual orientation. High-tech testing of 237 men and women of various self-reported sexual orientations revealed that CEOAE levels of gay and bisexual women were, on average, smaller than that found in heterosexual women, according to the study authors. "That is, it seems that CEOAE magnitude is related to sexual orientation in females," they conclude. No such differences were found between gay, bisexual, and straight men, however. The researchers believe the differences they noticed among women probably occurred in the womb, since the ability to hear CEOAEs is "highly stable through life." But if fetal androgen exposure can influence both inner ear function and sexual orientation, why then do women with twin brothers display lower CEOAE function, but no increase in rates for lesbianism compared with women in the general population? McFadden and Pasanen speculate that "different brain sites (controlling either hearing or sexuality) would be masculinized at slightly different times... (and) some brain sites might require lower levels of androgens than others to be masculinized fully." But they caution that inner ear function should not be thought of as a definitive "marker" for lesbianism or female bisexuality. Variations in CEOAE levels between individuals are "considerable," they point out, and "could not be used as an indicator of sexual orientation in individual people." SOURCE: Proceedings of the National Academy of Sciences (1998;95:2709-2713)