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