scholarly journals Serotonin Modulates Outward Potassium Currents in Mouse Olfactory Receptor Neurons

2013 ◽  
pp. 455-462 ◽  
Author(s):  
S. GAO ◽  
X. GUO ◽  
T. LIU ◽  
J. LIU ◽  
W. CHEN ◽  
...  
Keyword(s):  
Olfactory Receptor ◽  
Molecular Mechanisms ◽  
Mrna Level ◽  
Physiological Role ◽  
Potassium Currents ◽  
Olfactory Receptor Neurons ◽  
Pcr Analysis ◽  
Receptor Subtypes ◽  
Dependent Manner ◽  
Receptor Neurons

Monoaminergic neurotransmitter 5-hydroxytryptamine (5-HT), also known as serotonin, plays important roles in modulating the function of the olfactory system. However, thus far, the knowledge about 5-HT and its receptors in olfactory receptor neurons (ORNs) and their physiological role have not been fully characterized. In the present study, reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed the presence of 5-HT1A and 5-HT1B receptor subtypes in mouse olfactory epithelium at the mRNA level. With subtype selective antibodies and standard immunohistochemical techniques, both receptor subtypes were found to be positively labeled. To further elucidate the molecular mechanisms of 5-HT act on the peripheral olfactory transduction, the whole-cell patch clamp techniques were used on freshly isolated ORNs. We found that 5-HT decreased the magnitude of outward K+ current in a dose-dependent manner and these inhibitory effects were markedly attenuated by the 5-HT1A receptor blocker WAY-100635 and the 5-HT1B receptor antagonist GR55562. These data suggested that 5-HT may play a role in the modulation of peripheral olfactory signals by regulating outward potassium currents, both 5-HT1A and 5-HT1B receptors were involved in this regulation.

Intrinsically Bursting Olfactory Receptor Neurons

2007 ◽  
Vol 97 (2) ◽  
pp. 1052-1057 ◽  
Author(s):  
Y. V. Bobkov ◽  
B. W. Ache
Keyword(s):  
Olfactory Receptor ◽  
Action Potentials ◽  
Olfactory Receptor Neurons ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Network Function ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Bursting Neurons ◽  
Receptor Neurons

Rhythmically bursting neurons are fundamental to neuronal network function but typically are not considered in the context of primary sensory signaling. We now report intrinsically bursting lobster primary olfactory receptor neurons that respond to odors with a phase-dependent burst of action potentials. Rhythmic odor input as might be generated by sniffing entrains the intrinsic bursting rhythm in a concentration-dependent manner and presumably synchronizes the ensemble of bursting cells. We suggest such intrinsically bursting olfactory receptor cells provide a novel way for encoding odor information.

scholarly journals Carnosine synthase deficiency is compatible with normal skeletal muscle and olfactory function but causes reduced olfactory sensitivity in aging mice

2020 ◽  
Vol 295 (50) ◽  
pp. 17100-17113
Author(s):  
Lihua Wang-Eckhardt ◽  
Asisa Bastian ◽  
Tobias Bruegmann ◽  
Philipp Sasse ◽  
Matthias Eckhardt
Keyword(s):  
Skeletal Muscle ◽  
Antioxidant Activity ◽  
Muscle Contraction ◽  
Olfactory Receptor ◽  
Olfactory System ◽  
Physiological Role ◽  
Olfactory Receptor Neurons ◽  
Olfactory Sensitivity ◽  
Receptor Neurons ◽  
Deficient Mice

Carnosine (β-alanyl-l-histidine) and anserine (β-alanyl-3-methyl-l-histidine) are abundant peptides in the nervous system and skeletal muscle of many vertebrates. Many in vitro and in vivo studies demonstrated that exogenously added carnosine can improve muscle contraction, has antioxidant activity, and can quench various reactive aldehydes. Some of these functions likely contribute to the proposed anti-aging activity of carnosine. However, the physiological role of carnosine and related histidine-containing dipeptides (HCDs) is not clear. In this study, we generated a mouse line deficient in carnosine synthase (Carns1). HCDs were undetectable in the primary olfactory system and skeletal muscle of Carns1-deficient mice. Skeletal muscle contraction in these mice, however, was unaltered, and there was no evidence for reduced pH-buffering capacity in the skeletal muscle. Olfactory tests did not reveal any deterioration in 8-month-old mice lacking carnosine. In contrast, aging (18–24-month-old) Carns1-deficient mice exhibited olfactory sensitivity impairments that correlated with an age-dependent reduction in the number of olfactory receptor neurons. Whereas we found no evidence for elevated levels of lipoxidation and glycation end products in the primary olfactory system, protein carbonylation was increased in the olfactory bulb of aged Carns1-deficient mice. Taken together, these results suggest that carnosine in the olfactory system is not essential for information processing in the olfactory signaling pathway but does have a role in the long-term protection of olfactory receptor neurons, possibly through its antioxidant activity.

scholarly journals OSCILLATIONS OF THE TRANSEPITHELIAL POTENTIAL OF MOTH OLFACTORY SENSILLA ARE INFLUENCED BY OCTOPAMINE AND SEROTONIN

2001 ◽  
Vol 204 (16) ◽  
pp. 2781-2794 ◽  
Author(s):  
JAN DOLZER ◽  
STEFFI KRANNICH ◽  
KARIN FISCHER ◽  
MONIKA STENGL
Keyword(s):  
Action Potential ◽  
Olfactory Receptor ◽  
Olfactory Receptor Neurons ◽  
Dependent Manner ◽  
Impulse Frequency ◽  
Olfactory Sensilla ◽  
Transepithelial Potential ◽  
Accessory Cells ◽  
Receptor Neurons ◽  
Potential Activity

SUMMARY The biogenic amine octopamine is known to enhance the sensitivity of male moths to their species-specific pheromones in flight-tunnel experiments. This sensitization of pheromone-guided upwind flight is at least partly due to octopamine-dependent increases in the peak nerve impulse frequency of the pheromone response of olfactory receptor neurons. It is not known, however,whether octopamine exerts its effects directly on the electrical properties of the olfactory receptor neurons or indirectly, via modulation of the accessory cells of the sensillum. In extracellular tip recordings of pheromone-dependent trichoid sensilla on the antennae of male Manduca sexta moths, we investigated the effects of octopamine and serotonin on the transepithelial potential, which is generated by the activity of V-ATPases in sensillar accessory cells. In addition, the action potential activity of unstimulated olfactory receptor neurons was examined in the presence of biogenic amines. Under constant environmental conditions, the transepithelial potential oscillated regularly with periods of 2-8 min and with a 1-25 mV peak-to-peak amplitude over periods of several hours. These oscillatory intervals were interrupted by periods of relatively stable transepithelial potential, correlated with flight activity by the moth. Octopamine reduced the amplitude of the transepithelial potential oscillation and decreased the resistance of the sensillum preparation in a dose-dependent manner. Serotonin altered the waveform of the transepithelial potential, but did not change the resistance of the preparation. Thus, both amines affect the accessory cells, but have different targets in the regulation of the transepithelial potential. Neither amine significantly influenced the spontaneous action potential activity of the olfactory receptor neurons.

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