Nutrient-dependent / Pheromone-controlled Adaptive Evolution

J.V. Kohl Independent Researcher, Pheromones.com, Epworth, GA

Contact: jvkohl@bellsouth.net

This model of systems biology represents the conservation of bottom-up organization and top-down activation via:1.Nutrient stress-induced and social stress-induced intracellular changes in the microRNA (miRNA) / messenger RNA (mRNA) balance;2.Intermolecular changes in DNA (genes) and alternative splicing;3.Non-random experience-dependent stochastic variations in de novo gene expression and biosynthesis of odor receptors;4.The required gene-cell-tissue-organ-organ system pathway that links sensory input directly to gene activation in neurosecretory cells and to miRNA-facilitated learning and memory in the amygdala of the adaptively evolved mammalian brain;5.The required reciprocity that links gene expression to behavior that alters gene expression (i.e., reciprocity from genes to behavior and back) in model organisms like the honeybee.

Background: Chemical ecology drives adaptive evolution via 1) ecological niche construction, 2) social niche construction, 3) neurogenic niche construction, and 4) socio-cognitive niche construction (Kohl, 2012). Nutrients are metabolized to pheromones that condition effects on hormones that affect behavior in the same way that food odors condition behavior associated with food preferences. In mammals, the epigenetic effects of olfactory/pheromonal input (i.e., odors) calibrate and standardize molecular mechanisms for genetically predisposed receptor-mediated changes in intracellular signaling and stochastic gene expression in gonadotropin releasing hormone (GnRH) neurosecretory neurons of brain tissue. For example: glucose (Roland and Moenter, 2011) and pheromones alter the secretion of GnRH and luteinizing hormone (LH). Secretion of LH is the measurable proxy for genetically predisposed differences in hypothalamic GnRH pulse frequency and amplitude and the downstream effects of GnRH on the HPG axis and the HPA axis that provide feedback to the GnRH neuronal system. GnRH is the central regulator of genetically predisposed nutrient-dependent individual survival and pheromone-controlled species survival.

Conclusions: Across species comparisons of epigenetic effects on genetically predisposed nutrient-dependent and hormone-driven invertebrate and vertebrate social and sexual behavior indicate that human pheromones alter the development of the brain and behavior via the same molecular mechanisms (Krubitzer & Seelke, 2012). Those molecular mechanisms must be conserved across all species (see for example McFall-Ngai et al. in press) for adaptive evolution of the human brain and human behavior to occur (e.g., via properly timed reproductive sexual behavior of mammals).

Proof of concept (unpublished): Kohl, J. V., Kelahan, L. C., & Hoffmann, H. Human pheromones and nutrient chemicals: epigenetic effects on ecological, social, and neurogenic niches that affect behavior. Poster presented at Society for Social Neuroscience Annual Meeting. New Orleans, LA . Oct 11-12, 2012. http://posters.f1000.com/posters/browse/summary/1092668

Nature Nurtureature SEXUAL DIFFERENTIATION: Food odors and pheromones from

the same sex or from the opposite sex on sexual differentiation

GnRH Nerve cell migration

Olfactory placode

Olfactory bulbs

Limbic system

Hypothalamic GnRH

Hypothalamus (Links sensory input to neuroendocrinology)

Food odors Pheromones

From the opposite sex

From the same sex

Nose

GnRH pulse frequency and amplitude

Pituitary LH / FSH

Ovaries (estradiol)

Testes (testosterone)

Adrenals (other steroids)

HPG axis

HPA axis

extrahypothalamic GnRH

LH FSH

Gonads

Neurotransmission

Synaptogenesis Synaptolysis

Apoptosis

Synaptogenesis Synaptolysis

Apoptosis

Cyclic Tonic

Female Male

Positive Negative

Learning and Memory

Sexual orientation

Sexual identity

Sexual expression

Aging

GnRH-modulated neural circuitry, odor hedonics, mood, memory, motivation, expressions of affect, cognitive behavioral state, and potentiating responses to other stimuli epigenetically links NURTURE to NATURE

Estrogenic and androgenic metabolites

Adrenal metabolites

extrapituitary effects

PRE- and POSTNATAL pOPOSTNATAL

AOS OR MOS

AOS: accessory olfactory system; FSH: follicle stimulating hormone; GnRH: gonadotropin-releasing hormone; HPA: hypothalamic-pituitary-adrenal axis; HPG: hypothalamic-pituitary-gonadal axis; LH: luteinizing hormone; MOS: main olfactory system. Adapted from Kohl (1992) Luteinizing Hormone: the link between sex and the sense of smell?

Feedback

Adaptive evolution and the prenatal migration of GnRH neurosecretory neurons allows nutrient chemicals and human pheromones to alter GnRH pulsatility, which modulates the concurrent maturation of the neuroendocrine, reproductive, and central nervous systems, thus influencing the development of ingestive behavior, reproductive sexual behavior, and other behaviors.

PRENATAL

Epigenetic “tweaking” / embedding

Additional Considerations (not shown): The honeybee is an invertebrate model of adaptively evolved social behavior. The concept that is extended is the epigenetic tweaking of immense gene networks in superorganisms that solve problems through the exchange and the selective cancellation and modification of signals. In the context of this “biological embedding,” olfaction and odor receptors provide a clear evolutionary trail that can be followed from unicellular organisms to insects to humans.

It is now clear how an environmental drive evolved from that of nutrient uptake in unicellular organisms to that of pheromone-controlled socialization in insects. This makes it clearer that, in mammals, nutrients associated with food odors and pheromones associated with body odors cause changes in hormones, which have developmental affects on behavior in nutrient-dependent reproductively fit individuals that signal their fitness via pheromones.

Olfactory/pheromonal conditioning alters genetically predisposed, nutrient chemical-dependent, hormone-driven mammalian behavior and choices for pheromones that control reproduction via their effects on GnRH and LH (Kohl, unpublished). A form of GnRH that is also linked to sexual orientation appears to control the feedback loops of developmental processes required for nutrient uptake, alternative splicings, movement, reproduction, and the diversification of species from microbes to man.

References:Kohl, J.V. (Unpublished). Luteinizing hormone: The link between sex and the sense of smell? Annual Meeting of the Society for the Scientific Study of Sex. San Diego, CA. Nov 12-15, 1992.Kohl, J.V. (2012). Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology, 2: 17338. DOI: 10.3402/snp.v2i0.17338Krubitzer, L. A., & Seelke, A. M. H. (2012). Cortical evolution in mammals: The bane and beauty of phenotypic variability. PNAS, 109(Supplement 1), 10647-10654. McFall-Ngai, M., Hadfield, M. G., Bosch, T. C. G., Carey, H. V., Domazet-Loso, T., Douglas, A. E., et al. (in press). Animals in a bacterial world, a new imperative for the life sciences. Proc. Natl. Acad. Sci. USA. Roland, A. V., & Moenter, S. M. (2011). Regulation of gonadotropin-releasing hormone neurons by glucose. Trends Endocrinol Metab, 22(11), 443-449.