Epigenetic effects on memory: insects to mammals

System-Like Consolidation of Olfactory Memories in Drosophila
Isaac Cervantes-Sandoval, Alfonso Martin-Pena, Jacob A. Berry, and Ronald
L. Davis J. Neurosci. 2013;33 9846-9854 [subscription required]

Abstract excerpt: “These results argue that system consolidation is not a unique feature of the mammalian brain and memory systems, but rather a general and conserved feature of how different temporal memories are encoded from relatively simple to complex brains.”

My comment: Their findings fit within the context of what is currently known about the role of olfaction, odor receptors, hormones, and behavior across species. Nutrient-dependent pheromone-controlled epigenetic effects on hormone-organized and hormone-activated brain development enable the required plasticity during behavioral development of invertebrates and vertebrates via similar molecular mechanisms. The similarities exist regardless of brain size or complexity. Indeed, their data suggest to me that the molecular mechanisms of neurogenic and socio-cognitive niche construction are the same as those of ecological and social niche construction.

One difference is noteworthy. Immediate-early gene activation appears to lead to protein synthesis-dependent short-term memory in mammals that is protein synthesis-independent in flies. Speculatively, this could enable a more rapid response to changes in odor concentrations perceived by flies. All that’s required may be an epigenetic change in the microRNA/messenger RNA balance of neurons in the insect brain compared to changes in nutrient-dependent pheromone-controlled protein synthesis in gonadotropin releasing hormone (GnRH) neurosecretory neurons of the mammalian brain (e.g., in my model).

Article excerpt: “Nevertheless, the model for system consolidation processing of olfactory memories in Drosophila uses the same principles of interaction and reorganization between brain circuits, with early and late memories being supported by different brain regions. ”

My comment: In my model of nutrient-dependent/pheromone-controlled adaptive evolution, it is clear that invertebrate and vertebrate learning and memory are hormone-organized and hormone-activated. It is equally clear that classical conditioning of effects on hormones that affect behavior links olfaction and pheromones to the development of behavior associated with multisensory input (e.g., visual, auditory, tactile). As always, however, tone and foot shock pairing experiments by behaviorists do not exemplify classical conditioning in any species.

Difference between insects and mammals and claims that mammals, including humans, are not classically conditioned to respond to visual, auditory, and tactile input via associations with food odors and pheromones, just suffered another embarrassing refutation because the same molecular mechanisms are common to species from microbes to man. Thus, the insect-to-mammal learning and memory connection in this article  makes it more difficult for human pheromone-deniers to deny the similarities across species that clearly have again been demonstrated in the context of the molecular mechanisms of learning, memory, and hormone-driven organized and hormone-activated 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