Human pheromones and brain development

Nature | News

Human brain shaped by duplicate genes

Multiple copies of a gene may have boosted the computational power of our ancestors’ brains.

• Ewen Callaway

03 May 2012

——My comment: I’ve blogged here before about my friend, the late “Bob” Moss. But this latest work comes from UT Southwestern where he did his work.———–

It’s been more than 20 years since the late Robert L. Moss et al. published Gonadotropin-Releasing Hormone and Human Sexual Behavior (Moss, Dudley, & Riskind, 1991). Vertebrate gonadotropin releasing hormone (GnRH) neurons produce one of three different peptides, presumably because three paralogous GnRH genes originated from gene duplications (Oka, 2010).

The prenatal migration of GnRH neurons into the brain of humans is responsible for the direct connection from olfactory/pheromonal input to changes in hypothalamic GnRH pulse frequency, luteinizing hormone secretion, and hippocampal neurogenesis, which links food odors and social odors to learning and memory required for adaptive behaviors based on nutrient chemical availability and the presence or absence of conspecifics. It is likely that anything that alters GnRH pulse frequency, whether it’s the gene or genes responsible for Kallmann’s syndrome, or nutrient chemical availability that alters maturation of the brain and behavior will alter learning and memory associated with food acquisition and mate choice as preferences develop based on prenatal chemical exchanges in placental mammals and the postnatal effects of food odors and pheromones.

Thus, the epigenetic effects of chemicals from our sensory environment on GnRH are probably essential to the development of an evolved brain and behavior involved in seeking out proper nutrition and reproductively “fit” mates. “Bob” Moss knew he would not be able to prove the cause and effect relationship that continues to show up in the newest literature on human brain development, but he also knew that someone would prove the link from GnRH to nutrition dependent human sexual behavior. Clearly, others are getting closer to that proof, as is seen in this latest news on gene duplications and human brain development. It may nevertheless be important to keep in mind that evolved brain development is dependent on nutrient chemicals and pheromones that alter receptor-mediated intracellular signaling and stochastic gene expression in species from microbes to man, if only to keep evolved brain development in its proper context.

Moss, R. L., Dudley, C. A., & Riskind, P. N. (1991). Gonadotropin releasing hormone and human sexual behavior. In C. B. Nemeroff (Ed.), Neuropeptides and Psychiatric Disorders. Washington, D.C: American Psychiatric Press.

Oka, Y. (2010). Electrophysiological Characteristics of Gonadotrophin-Releasing Hormone 1-3 Neurones: Insights From a Study of Fish Brains. Journal of Neuroendocrinology, 22(7), 659-663.

Human Pheromones and Consilience

Consilience Conference Celebrates Unity of Knowledge In Biology, Social Science, and Humanities – free audiotaped interviews

My comments:

What makes the answer to one question more important than the answer to another question in attempts to understand proximate and ultimate cause across the levels of analysis that are required to link sensory input to evolution and behavior? Evolution of the genotype and its phenotypic expression can only be congruently addressed via the gene, cell, tissue, organ, organ system pathway. No part of this pathway lies outside what is required for a coherent understanding of consilience.

The requirements for proximate bottom-up causal organization and proximate top-down causal activation of this pathway include the reciprocity that is ultimately required for evolution. These requirements are met in the following example of cause and effect.

1) Nutrient chemicals cause receptor-mediated changes in intracellular signaling that cause stochastic gene expression – a bottom-up approach to the biology of consilience.

2) The metabolism of nutrient chemicals to pheromones allows chemicals from the social environment to cause receptor-medicated changes in intracellular signaling that cause stochastic gene expression – a top-down approach to the biology of consilience.

3) Organisms without the ability to acquire sufficient nutrient chemicals do not produce the required pheromones and they do not reproduce via receptor-mediated gene activation. Evolution does not occur.

4) Organisms with genetically predisposed behaviors that allow them to acquire sufficient nutrient chemicals establish their ecological niche via receptor-mediated gene activation. Evolution occurs.

Genetically predisposed nutrient dependent ecotypes establish pheromone dependent social niches. These nutrient dependent ecotypes and social niches are fundamental requirements for evolution in species from microbes to man.

The nutrient chemical / pheromone dependent social niche contributes to similarities and differences in the neurogenic niches required for invertebrate and vertebrate brain development and behavior. Adaptive evolution of the brain and behavior is calibrated by nutrients, but it is standardized and controlled by pheromones.

A fundamental question that incorporates proximate and ultimate cause has become one of pattern recognition. Why isn’t the reason for the conserved molecular biology common to all species addressed as the most important of all questions to be answered?

A basic understanding of this conserved molecular biology is required for a coherent understanding of evolution, its congruence, and the pattern recognition of consilience (i.e., the gene, cell, tissue, organ, organ system pathway). Nutrient chemicals and pheromones cause changes in intracellular signaling and gene expression in cells of tissue in the most important organ of all organ systems involved in behavior: the brain.

Conciliatory caveat: An evolved brain is not required. Nutrient chemicals and pheromones cause changes in intracellular signaling and behavior in unicellular organisms and in all species via molecular mechanisms that are so similar as to be readily recognized in a pattern of evolution.

When this pattern recognition is too technically difficult to detail, scientists could simply say that all organisms are what they eat and their peers recognize them via the pheromones they produce. Food preferences and people preferences develop due to receptor-mediated events driven by chemicals, or simply put it’s the “chemistry”. Once this pattern is recognized we could simply say that ultimately, olfaction and odor receptors provide a clear evolutionary trail that can be followed from unicellular organisms to insects to humans, as was my conclusion in Kohl (2012).

Kohl, J. V. (2012). Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology, 2, 17338 – DOI: 17310.13402/snp.v17332i17330.17338.

Pattern recognition: How rational is that?

Study suggests that analytic thinking can undermine religious belief

“Recently there’s been an emerging consensus among [researchers] … that a lot of religious beliefs are grounded in intuitive processes,” says Will Gervais, a graduate student at the University of British Columbia, Vancouver, in Canada and a co-author of the new study, published today in Science.

____________________

My comments:

Pattern recognition is required of scientists who have changed the attitudes of their peers. It is also important when comparing analytical thinking to beliefs.

Here’s a pattern

Non-random mutation, as evidenced by ‘hot’ and ‘cold’ genes involved in amino-acid biosynthesis, energy metabolism , and catabolism of specific compounds (Martincorena, Seshasayee , & Luscombe, 2012) is conceptualized in a model for adaptive evolution where 1) nutrient chemicals calibrate intracellular signaling and stochastic gene expression, and 2) the metabolism of nutrients to pheromones standardizes and controls reproduction (Kohl, 2012).

The honeybee is the invertebrate model organism that extends the common molecular biology across species from microbes to man. The pattern is hard to miss, and additional support for that model can found in a recent report on a vertebrate model organism of speciation. Stickleback evolution is accelerated by the use of pre-existing genetic variation, not random mutation (Jones et al., 2012).  Although random mutation may be involved, it is pre-existing genetic variation that allows a cell to adapt to changes in the availability of nutrients from its environment. This ability appears to be programmed into the first living cells. Receptor-mediated cellular changes in the intracellular metabolism of the nutrients enables cell to cell signaling that varies with the metabolism of nutrients to pheromones that control reproduction.

This pattern can be recognized by a general audience. All scientists need to say is that food odors cause us to eat food that metabolizes to pheromones that cause us to develop preferences for other people. For example, in placental mammals, in utero nutrient chemical exchange precedes nutrient chemicals provided though lacation. These nutrient chemicals are associated with the pheromones of the mother and result in social bonding.  In this context, pheromones are social odors just as they are in bacteria, in the honeybees, in the  sticklebacks, and all other species.

The ability to recognize patterns across species helps to ensure that at some point this common thread, which involves only only food odors and social odors,  may allow analytical thinkers to use olfaction and odor receptors to follow a clear evolutionary trail from unicellular organisms to insects to humans.

Jones, F. C., Grabherr, M. G., Chan, Y. F., Russell, P., Mauceli, E., Johnson, J., et al. (2012). The genomic basis of adaptive evolution in threespine sticklebacks. Nature, 484(7392), 55-61.

Kohl, J. V. (2012). Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology , 2, 17338 – DOI: 17310.1340 2/snp.v1733 2i17330.173 38.

Martincorena, I., Seshasayee , A. S. N., & Luscombe, N. M. (2012). Evidence of non-random mutation rates suggests an evolutionary risk management strategy. Nature, advance online publicatio n, doi:10.103 8/nature109 95.

More than speculation: adaptive evolution in species from microbes to man

Excerpt from:  Genetic Variation of an Odorant Receptor OR7D4 and Sensory Perception of Cooked Meat Containing Androstenone

“It is tempting to speculate that certain ORs or variants of ORs influence dietary selection. These ORs might be selected during human evolution based on the available food source in a given habitat.” (Lunde et al., 2012)

————————————————–

My Comment:

I addressed this speculation with my model of nutrient chemical calibration of individual survival where the nutrient chemicals are metabolized to pheromones that standardize and control reproduction and species survival (Kohl, 2012).

This is what occurs in species from microbes to man, but it is best detailed using the honeybee model organism and what is currently known about the molecular biology, which allows the epigenetic effects of nutrient chemicals and pheromones to be the primary determining factors for species survival (i.e., not random mutations).

As suggested by these authors in the quote above, nutrient chemicals establish the ecological niches, which establish the social niches. In vertebrates the social niches are linked by pheromones to neurogenic niches in the hypothalamus that alter luteinizing hormone, olfactory bulb neurogenesis and hippocampal neurogenesis, learning and memory.

Of course, because I’ve dismissed evolutionary theory that involves random mutations, and used the epigenetic effects of olfactory/pheromonal input on OR variants, which provide a clear evolutionary trail that can be followed from unicellular organisms to insects to humans, my work has been largely ignored. So, it is great to see others speculate about what I have modeled across species from microbes to man. Perhaps now evolutionary theorists, philosophers, and theologians can compare alternative comprehensive models of individual and species survival based on what’s known about current molecular biology.

References (all open access publications)

(Kohl, 2012) Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology, 2: 17338. http://dx.doi.org/10.3402/snp.v2i0.17338

See also: (Jones et al., 2012) The genomic basis of adaptive evolution in threespine sticklebacks. Nature, 484, 7392:55-61

Jones, F. C., Grabherr, M. G., Chan, Y. F., Russell, P., Mauceli, E., Johnson, J., et al. (2012). The genomic basis of adaptive evolution in threespine sticklebacks. Nature, 484(7392), 55-61.

Kohl, J. V. (2012). Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology, 2, 17338 – DOI: 17310.13402/snp.v17332i17330.17338.

Lunde, K., Egelandsdal, B. r., Skuterud, E., Mainland, J. D., Lea, T., Hersleth, M., et al. (2012). Genetic Variation of an Odorant Receptor OR7D4 and Sensory Perception of Cooked Meat Containing Androstenone. PLoS ONE, 7(5), e35259.

Human Pheromones: The smell of the scientific universe expanding

Pheromone ‘Ome,’ the Sound of the Scientific Universe Expanding

[He said, “All the omes derive to some extent from the genome,” and key to all of them is that an ome represents “the entirety of the thing being studied.” ]

My comment:

The entirety of the thing cannot be studied in the absence of its sensory environment. The epigenetic effects of nutrient chemicals and pheromones are responsible for the genome’s evolution and diversification of “omes” from microbes to man.