scholarly journals Adaptation of olfactory receptor abundances for efficient coding

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Tiberiu Teşileanu ◽  
Simona Cocco ◽  
Rémi Monasson ◽  
Vijay Balasubramanian
Keyword(s):  
Sensory Neurons ◽  
Olfactory Receptor ◽  
Environmental Changes ◽  
Olfactory Receptors ◽  
Olfactory Sensory Neurons ◽  
Birth And Death Processes ◽  
Global Context ◽  
Efficient Coding ◽  
Receptor Usage ◽  
Striking Fact

Olfactory receptor usage is highly heterogeneous, with some receptor types being orders of magnitude more abundant than others. We propose an explanation for this striking fact: the receptor distribution is tuned to maximally represent information about the olfactory environment in a regime of efficient coding that is sensitive to the global context of correlated sensor responses. This model predicts that in mammals, where olfactory sensory neurons are replaced regularly, receptor abundances should continuously adapt to odor statistics. Experimentally, increased exposure to odorants leads variously, but reproducibly, to increased, decreased, or unchanged abundances of different activated receptors. We demonstrate that this diversity of effects is required for efficient coding when sensors are broadly correlated, and provide an algorithm for predicting which olfactory receptors should increase or decrease in abundance following specific environmental changes. Finally, we give simple dynamical rules for neural birth and death processes that might underlie this adaptation.

scholarly journals Adaptation of olfactory receptor abundances for efficient coding

2018 ◽  
Author(s):  
Tiberiu Tesileanu ◽  
Simona Cocco ◽  
Remi Monasson ◽  
Vijay Balasubramanian
Keyword(s):  
Sensory Neurons ◽  
Olfactory Receptor ◽  
Environmental Changes ◽  
Olfactory Receptors ◽  
Olfactory Sensory Neurons ◽  
Birth And Death Processes ◽  
Global Context ◽  
Efficient Coding ◽  
Receptor Usage ◽  
Striking Fact

Olfactory receptor usage is highly heterogeneous, with some receptor types being orders of magnitude more abundant than others. We propose an explanation for this striking fact: the receptor distribution is tuned to maximally represent information about the olfactory environment in a regime of efficient coding that is sensitive to the global context of correlated sensor responses. This model predicts that in mammals, where olfactory sensory neurons are replaced regularly, receptor abundances should continuously adapt to odor statistics. Experimentally, increased exposure to odorants leads variously, but reproducibly, to increased, decreased, or unchanged abundances of different activated receptors. We demonstrate that this diversity of effects is required for efficient coding when sensors are broadly correlated, and provide an algorithm for predicting which olfactory receptors should increase or decrease in abundance following specific environmental changes. Finally, we give simple dynamical rules for neural birth and death processes that might underlie this adaptation.

Temporal Development of Cyclic Nucleotide-Gated and Ca2+-Activated Cl− Currents in Isolated Mouse Olfactory Sensory Neurons

2007 ◽  
Vol 98 (1) ◽  
pp. 153-160 ◽  
Author(s):  
Anna Boccaccio ◽  
Anna Menini
Keyword(s):  
Sensory Neurons ◽  
Flash Photolysis ◽  
Olfactory Receptors ◽  
Cell Voltage ◽  
Equilibrium Potential ◽  
Olfactory Sensory Neurons ◽  
Second Phase ◽  
Current Response ◽  
Intact Mouse ◽  
Secondary Current

A Ca2+-activated Cl− current constitutes a large part of the transduction current in olfactory sensory neurons. The binding of odorants to olfactory receptors in the cilia produces an increase in cAMP concentration; Ca2+ enters into the cilia through CNG channels and activates a Cl− current. In intact mouse olfactory sensory neurons little is known about the kinetics of the Ca2+-activated Cl− current. Here, we directly activated CNG channels by flash photolysis of caged cAMP or 8-Br-cAMP and measured the current response with the whole cell voltage-clamp technique in mouse neurons. We measured multiphasic currents in the rising phase of the response at −50 mV. The current rising phase became monophasic in the absence of extracellular Ca2+, at +50 mV, or when most of the intracellular Cl− was replaced by gluconate to shift the equilibrium potential for Cl− to −50 mV. These results show that the second phase of the current in mouse intact neurons is attributed to a Cl− current activated by Ca2+, similarly to previous results on isolated frog cilia. The percentage of the total saturating current carried by Cl− was estimated in two ways: 1) by measuring the maximum secondary current and 2) by blocking the Cl− channel with niflumic acid. We estimated that in the presence of 1 mM extracellular Ca2+ and in symmetrical Cl− concentrations the Cl− component can constitute up to 90% of the total current response. These data show how to unravel the CNG and Ca2+-activated Cl− component of the current rising phase.

scholarly journals Human Olfactory Receptors: Novel Cellular Functions Outside of the Nose

2018 ◽  
Vol 98 (3) ◽  
pp. 1739-1763 ◽  
Author(s):  
Désirée Maßberg ◽  
Hanns Hatt
Keyword(s):  
Sensory Neurons ◽  
Olfactory Receptors ◽  
Olfactory Sensory Neurons ◽  
Cell Recognition ◽  
Limited Data ◽  
Cellular Functions ◽  
Functional Roles ◽  
Alternative Pathways ◽  
Therapeutic Tools ◽  
Cancer Tissues

Olfactory receptors (ORs) are not exclusively expressed in the olfactory sensory neurons; they are also observed outside of the olfactory system in all other human tissues tested to date, including the testis, lung, intestine, skin, heart, and blood. Within these tissues, certain ORs have been determined to be exclusively expressed in only one tissue, whereas other ORs are more widely distributed in many different tissues throughout the human body. For most of the ectopically expressed ORs, limited data are available for their functional roles. They have been shown to be involved in the modulation of cell-cell recognition, migration, proliferation, the apoptotic cycle, exocytosis, and pathfinding processes. Additionally, there is a growing body of evidence that they have the potential to serve as diagnostic and therapeutic tools, as ORs are highly expressed in different cancer tissues. Interestingly, in addition to the canonical signaling pathways activated by ORs in olfactory sensory neurons, alternative pathways have been demonstrated in nonolfactory tissues. In this review, the existing data concerning the expression, as well as the physiological and pathophysiological functions, of ORs outside of the nose are highlighted to provide insights into future lines of research.

scholarly journals Effects of Odor Stimulation on Antidromic Spikes in Olfactory Sensory Neurons

2008 ◽  
Vol 100 (6) ◽  
pp. 3074-3085 ◽  
Author(s):  
John W. Scott ◽  
Lisa Sherrill
Keyword(s):  
Electrical Stimulation ◽  
Sensory Neurons ◽  
Olfactory Receptor ◽  
Olfactory Receptor Neuron ◽  
Olfactory Nerve ◽  
Receptor Neuron ◽  
Odor Stimulus ◽  
Olfactory Sensory Neurons ◽  
Strongly Correlated ◽  
Receptor Neurons

Spikes were evoked in rat olfactory sensory neuron (OSN) populations by electrical stimulation of the olfactory bulb nerve layer in pentobarbital anesthetized rats. The latencies and recording positions for these compound spikes showed that they originated in olfactory epithelium. Dual simultaneous recordings indicated conduction velocities in the C-fiber range, around 0.5 m/s. These spikes are concluded to arise from antidromically activated olfactory sensory neurons. Electrical stimulation at 5 Hz was used to track changes in the size and latency of the antidromic compound population spike during the odor response. Strong odorant stimuli suppressed the spike size and prolonged its latency. The latency was prolonged throughout long odor stimuli, indicating continued activation of olfactory receptor neuron axons. The amounts of spike suppression and latency change were strongly correlated with the electroolfactogram (EOG) peak size evoked at the same site across odorants and across stimulus intensities. We conclude that the curve of antidromic spike suppression gives a reasonable representation of spiking activity in olfactory sensory neurons driven by odorants and that the correlation of peak spike suppression with the peak EOG shows the accuracy of the EOG as an estimate of intracellular potential in the population of olfactory sensory neurons. In addition, these results have important implications about traffic in olfactory nerve bundles. We did not observe multiple peaks corresponding to stimulated and unstimulated receptor neurons. This suggests synchronization of spikes in olfactory nerve, perhaps by ephaptic interactions. The long-lasting effect on spike latency shows that action potentials continue in the nerve throughout the duration of an odor stimulus in spite of many reports of depolarization block in olfactory receptor neuron cell bodies. Finally, strong odor stimulation caused almost complete block of antidromic spikes. This indicates that a very large proportion of olfactory axons was activated by single strong odor stimuli.

scholarly journals Coordination of olfactory receptor choice with guidance receptor expression and function in olfactory sensory neurons

PLoS Genetics ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. e1007164 ◽  
Author(s):  
Puneet Dang ◽  
Stephen A. Fisher ◽  
Derek J. Stefanik ◽  
Junhyong Kim ◽  
Jonathan A. Raper
Keyword(s):  
Sensory Neurons ◽  
Olfactory Receptor ◽  
Receptor Expression ◽  
Olfactory Sensory Neurons ◽  
And Function

scholarly journals Lineage does not regulate the sensory synaptic input of projection neurons in the mouse olfactory bulb

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Luis Sánchez-Guardado ◽  
Carlos Lois
Keyword(s):  
Olfactory Bulb ◽  
Sensory Neurons ◽  
Synaptic Input ◽  
Pyramidal Neurons ◽  
Cell Lineage ◽  
Olfactory Receptors ◽  
Projection Neurons ◽  
Olfactory Sensory Neurons ◽  
Neuronal Progenitors ◽  
Functional Relevance

Lineage regulates the synaptic connections between neurons in some regions of the invertebrate nervous system. In mammals, recent experiments suggest that cell lineage determines the connectivity of pyramidal neurons in the neocortex, but the functional relevance of this phenomenon and whether it occurs in other neuronal types remains controversial. We investigated whether lineage plays a role in the connectivity of mitral and tufted cells, the projection neurons in the mouse olfactory bulb. We used transgenic mice to sparsely label neuronal progenitors and observed that clonally related neurons receive synaptic input from olfactory sensory neurons expressing different olfactory receptors. These results indicate that lineage does not determine the connectivity between olfactory sensory neurons and olfactory bulb projection neurons.

scholarly journals Lineage does not regulate the connectivity of projection neurons in the mouse olfactory bulb

2019 ◽  
Author(s):  
Luis Sánchez-Guardado ◽  
Carlos Lois
Keyword(s):  
Olfactory Bulb ◽  
Sensory Neurons ◽  
Pyramidal Neurons ◽  
Cell Lineage ◽  
Olfactory Receptors ◽  
Projection Neurons ◽  
Olfactory Sensory Neurons ◽  
Neuronal Progenitors ◽  
Neuronal Types ◽  
Functional Relevance

AbstractLineage regulates the synaptic connections between neurons in some regions of the invertebrate nervous system. In mammals recent experiments suggest that cell lineage determines the connectivity of pyramidal neurons in the neocortex, but the functional relevance of this phenomenon and whether it occurs in other neuronal types remains controversial. We investigated whether lineage plays a role in the connectivity of mitral and tufted cells, the projection neurons in the mouse olfactory bulb. We used transgenic mice to label neuronal progenitors sparsely and observed that clonally related neurons receive synaptic input from olfactory sensory neurons expressing different olfactory receptors. These results indicate that lineage does not determine the connectivity between olfactory sensory neurons and olfactory bulb projection neurons.

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