Excerpt: “… gray lines show the path followed by a rat as it moves around a box looking for pieces of food.”
Excerpt: John Stein, professor of physiology at Oxford University, said: “This is great news and well deserved. I remember how great was the scoffing in the early 1970s when John first described place cells. ‘Bound to be an artifact’, ‘he clearly underestimates rats’ sense of smell’ were typical reactions. Now, like so many ideas that were at first highly controversial, people say: ‘Well that’s obvious.’”
My comment: It’s obvious that he underestimated the sense of smell
The Nobel Prize in Physiology or Medicine 2004 was awarded jointly to Richard Axel and Linda B. Buck “for their discoveries of odorant receptors and the organization of the olfactory system”
See: Feedback loops link odor and pheromone signaling with reproduction (Boehm,U., Zou, Z., and Linda B. Buck, 2005)
Excerpt: “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.”
Kohl et al., (2001) Human pheromones: integrating neuroendocrinology and ethology
Excerpt: “Given mammalian models, olfactory conditioning of a GnRH-directed neuroendocrine response may lead to a change in the sex steroid hormones T and E, which would be a change that also is manifest in behavior. This neuroendocrine link between social environmental sensory (i.e., olfactory) input and the neuroendocrinology of reproduction appears to preclude any involvement of cognition. Thus, the affect-cognition question is sublimated by the effect of pheromones on the neuroendocrine system, and presumably on behavior.”
Kohl (2012) Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors.
Excerpt: “…Olfaction and odor receptors provide a clear evolutionary trail that can be followed from unicellular organisms to insects to humans…”
My comment: If you are not able to understand the link from the 2014 Nobel prize in physiology and medicine to works by 2004 Nobel Laureates, Linda Buck and Richard Axel, you should probably begin to learn how “Spatial Olfactory Learning Contributes to Place Field Formation in the Hippocampus”
Place cells are conditioned to respond during thermodynamic cycles of protein biosynthesis and degradation. These cycles link the absence of food during seemingly futile cycles or to the presence of food rewards. For example, epigenetic effects of food odors and the conserved molecular mechanisms of epigenetically-effected RNA-directed DNA methylation link olfactory/pheromonal input to the morphological and behavioral diversity of species from microbes to man. RNA-mediated events link the odor experience-driven de novo creation of olfactory receptor genes to amino acid substitutions that differentiate cell types and to chromosomal rearrangements that differentiate species without the pseudoscientific nonsense of mutations and the evolution of biodiversity.
For example, earlier today Jon Lieff detailed the sequence of events that lead from nutrient uptake to cell type differentiation of glial cells. Glia surround neurons; hold them in place; supply neurons with nutrients and oxygen; insulate neurons from each other, and they perform other functions that important to learning and memory. See: Versatile Lipoproteins in Healthy Brains and Alzheimers
Excerpt: “App, the molecule that is the precursor to amyloid-β, is cut by the enzymes beta secretase and gamma secretase creating the amyloid-β molecules. These two enzymes have a variety of functions in the synapse. One is related to pruning synapses, stopping new brain cell creation and increasing cell death. The other is related to protection of synapses.
The cutting process makes 2 types of amyloid-β with different numbers of amino acids—either 40 amino acids or 42. The 42 variety creates the plaques of Alzheimer’s. The mutation mentioned above, also, increases the 42 version.
The APP and the secretase are usually in different compartments of the pipeline, but in Alzheimer’s they share the same compartment and produce more of the 42 variety.”
My comment: The nutrient-dependent substitution of two amino acids leads to creation and removal of the plaques of Alzheimer’s manifested in the context of mutations that also are associated with 42 amino acids and cell type differentiation. However, the epigenetic effects of nutrient-uptake on amino acid substitutions can be separated from the unknown effects of mutations in the context of typical and atypical cell type differentiation linked from spatial olfactory learning during themodynamic cycles of protein biosynthesis and degradation to “…the path followed by a rat as it moves around a box looking for pieces of food.” The seemingly futile thermodynamic cycles end when the rat ingests the food it found via the food’s odor. That is how the food odor is linked from its epigenetic effects on RNA-directed DNA methylation to recognition of self vs other differences in conspecifics that find sources of food that lead to metabolism and production of species-specific pheromones that control the physiology of reproduction. Nutrient-dependent pheromone-controlled reproduction can also be linked from the decline of olfactory acuity and specificity to increased mortality, and to increased morbidity associated with Alzheimer’s disease in humans via conserved molecular mechanisms that link the epigenetic landscape to the physical landscape of DNA in the organized genomes of species from microbes to man. See: Olfactory Dysfunction Predicts 5-Year Mortality in Older Adults.