Strength in diversity: functional diversity among olfactory neurons of the same type

Abstract

Most animals depend upon olfaction to find food, mates, and to avoid predators. An animal's olfactory circuit helps it sense its olfactory environment and generate critical behavioral responses. The general architecture of the olfactory circuit, which is conserved across species, is made up of a few different neuronal types including first-order receptor neurons, second-and third-order neurons, and local interneurons. Each neuronal type differs in their morphology, physiology, and neurochemistry. However, several recent studies have suggested that there is intrinsic diversity even among neurons of the same type and that this diversity is important for neural function. In this review, we first examine instances of intrinsic diversity observed among individual types of olfactory neurons. Next, we review potential genetic and experience-based plasticity mechanisms that underlie this diversity. Finally, we consider the implications of intrinsic neuronal diversity for circuit function. Overall, we hope to highlight the importance of intrinsic diversity as a previously underestimated property of circuit function.

Mechanism underlying starvation-dependent modulation of olfactory behavior in Drosophila larva

“…This study along with previous studies from our lab and others raise the possibility that starvation differentially modulates individual OSNs. Indeed, individual OSNs exhibit functional diversity that may lend them to differential modulation by the animal's internal state [46][47][48] . This diversity may stem from heterogeneous GABA B R levels on the terminals of individual OSNs that determine differential presynaptic gain control 16 .…”

Conformational Sensing by a Mammalian Olfactory Receptor

“…[24,26] Additionally, in UbI7 (+ / +) OSNs the OMP promoter turns I7 expressiono n late in the developmental program such that dissociated OSNs not yet mature may be expressing little or no I7. [32] These factors, in addition to the heterogeneity in OSN populations expressing the same OR, [33] general OR transgene effects, [34] and the fragile nature of lived issociated neurons, likely all contribute to cell-to-cell variations in the I7 response magnitude and preventt he expression of optimally functional I7 in all dissociated UbI7 (+ / +) OSNs.N evertheless, counting the cells showing ap ositive response to the different odorants supported the conclusion that 3-trans is ab etter I7 agonist-either more potent, more efficacious or both-than octanal, and 3-cis is not as potent (or efficacious) as octanal.…”

Covid-19, Anosmia, Ageusia: Prospective Observational Study, Follow-Up Three and Eight Months Later

“…The axon passes through the cribriform plate of the ethmoid to reach the olfactory bulb. Axons from several neurons converge and form the olfactory nerve (1 st pair of cranial nerves or I), which is very short and consists of many nerve threads [10]. Olfactory neurons do not express ACE2 and TMPRSS2, and it is still unclear if SARS-CoV-2 can infect human neurons [11].…”

“…This is why anosmia prevents food aroma perception. The final sensation of taste is influenced by complex and redundant stimulations of the five senses and memory [10,15].…”