It is suggested that the brain response of a food odor sensed retro-nasally is related to satiety.
A specific obp can play multiple roles in sensing different types of complex odors, since the odor sensing is dependent on several obps that are part of a specific odor code [ 33].
In that model, attractive odors sensed by the AWA neuron will activate the serotonergic neuron NSM to release serotonin, thereby ultimately increasing the feeding rate.
These findings reveal an extraordinary process that involves inactive odor-sensing neurons being depleted relative to active ones over time.
Indeed, it is known that the relative abundance of each type of odor-sensing neuron changes with age and experience, and that these changes might be caused by variations in the lifespans of the neurons.
Each odor-sensing neuron in the nose of a mammal contains just one kind of odorant receptor protein, although mammalian genomes typically encode 1000 or so different kinds of receptor proteins.
They found that in odor-sensing neurons, H2BE replaces H2B to an extent that depends on the amount of activity experienced by the neuron: H2BE is nearly undetectable in highly active neurons, but almost completely replaces H2B in neurons that are inactive.
Alain Corbin, a French intellectual who has written about odors, the senses, cannibalism and other topics, described the general change in the European attitude toward the boundary between sea and land in "Lure of the Sea: The Discovery of the Seaside, 1750-1840".
One unproven theory, based on anecdotal evidence, is that, simply, the I.S.S. is smelly: the odor dampens astronauts' sense of smell, which then affects their taste buds.
The animals know their numbers are too high because they can sense odor chemicals called pheromones emitted by their peers.
