Integration of postnatal visual input

Birth gets the brain ready to sense the world

News Article Excerpt: “…the birth of mouse pups leads to a drop in serotonin levels in the newborn’s brain, triggering the formation of neural circuits in the barrel cortex and in the lateral geniculate nucleus (LGN), a brain region that processes visual information.”

Journal Article Excerpt: “Interestingly, the regulatory mechanisms described here were also found to regulate eye-specific segregation in the visual system, suggesting that they are utilized in various brain regions. Our results shed light on roles of birth and serotonin in sensory map formation.”

My comment: In our 1996 Hormones and Behavior review: From Fertilization to Adult Sexual Behavior,  we attributed sex differences in hormone-organized and hormone activated behaviors to conserved molecular epigenetic mechanisms in mammals that clearly involve gonadotropin releasing hormone (GnRH) and its downstream effects on the development of other neuronal systems, such as the serotoninergic neuronal system. Other neuronal systems provide feedback on hypothalamic GnRH pulse frequency, which integrates internal and external sensory input throughout life.

Integration of postnatal visual input does not typically occur outside the context of olfactory/pheromonal input, which explains why male mammals exhibit a surge in GnRH-directed luteinizing hormone secretion that appears to masculinize the brain via association with increased testosterone levels and exposure to maternal pheromones associated with food odors. This explains how Olfaction spontaneously highlights [the] visual saliency map, and that explains spontaneous binding between congruent olfactory and visual information that appears to form “…a multimodal saliency map where the visual object with added olfactory presence gained increased perceptual saliency.”

This saliency could also be explained in the context of Feedback loops [that] link odor and pheromone signaling with reproduction. In that context, “Indications that GnRH peptide plays an important role in the control of sexual behaviors suggest that pheromone effects on these behaviors might also involve GnRH neurons.” (p 683). Thus, taken together the role of nutrient-dependent pheromone-controlled adaptive evolution in species from microbes to man suggests focus on visual input and serotonin might be best considered only after-the-fact, which means only after the role of epigenetic effects of olfactory/pheromonal input on GnRH regulation of sex differences in neuronal systems and their feedback are considered during the postnatal development of the mammalian brain.

In my model, birth regulates the postnatal continuation of prenatal sensory map formation through GnRH signaling via epigenetic effects of olfactory/pheromonal input on the genetically predisposed sexual differentiation of the brain and behavior. Clearly, visual input is involved in serotonin signaling but the role of visual input should not be elevated to a status that indicates either visual input or serotonin signaling is primarily involved in brain development and behavior.

About James V. Kohl 1308 Articles
James Vaughn Kohl was the first to accurately conceptualize human pheromones, and began presenting his findings to the scientific community in 1992. He continues to present to, and publish for, diverse scientific and lay audiences, while constantly monitoring the scientific presses for new information that is relevant to the development of his initial and ongoing conceptualization of human pheromones. Recently, Kohl integrated scientific evidence that pinpoints the evolved neurophysiological mechanism that links olfactory/pheromonal input to genes in hormone-secreting cells of tissue in a specific area of the brain that is primarily involved in the sensory integration of olfactory and visual input, and in the development of human sexual preferences. His award-winning 2007 article/book chapter on multisensory integration: The Mind’s Eyes: Human pheromones, neuroscience, and male sexual preferences followed an award winning 2001 publication: Human pheromones: integrating neuroendocrinology and ethology, which was coauthored by disinguished researchers from Vienna. Rarely do researchers win awards in multiple disciplines, but Kohl’s 2001 award was for neuroscience, and his 2007 “Reiss Theory” award was for social science. Kohl has worked as a medical laboratory scientist since 1974, and he has devoted more than twenty-five years to researching the relationship between the sense of smell and the development of human sexual preferences. Unlike many researchers who work with non-human subjects, medical laboratory scientists use the latest technology from many scientific disciplines to perform a variety of specialized diagnostic medical testing on people. James V. Kohl is certified with: * American Society for Clinical Pathology * American Medical Technologists James V. Kohl is a member of: * Society for Neuroscience * Society for Behavioral Neuroendocrinology * Association for Chemoreception Sciences * Society for the Scientific Study of Sexuality * International Society for Human Ethology * American Society for Clinical Laboratory Science * Mensa, the international high IQ society