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.

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 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.

scholarly journals Functional Asymmetries in Cockroach ON and OFF Olfactory Receptor Neurons

2011 ◽  
Vol 105 (2) ◽  
pp. 834-845 ◽  
Author(s):  
Maria Burgstaller ◽  
Harald Tichy
Keyword(s):  
Olfactory Receptor ◽  
Olfactory Receptor Neurons ◽  
Differential Sensitivity ◽  
Background Concentration ◽  
High Concentration ◽  
Impulse Frequency ◽  
Lemon Oil ◽  
Receptor Neurons ◽  
Concentration Changes ◽  
High Concentration Range

The ON and OFF olfactory receptor neurons (ORNs) on the antenna of the American cockroach respond to the same changes in the concentration of the odor of lemon oil, but in the opposite direction. The same jump in concentration raises impulse frequency in the ON and lowers it in the OFF ORN and, conversely, the same concentration drop raises impulse frequency in the OFF and lowers it in the ON ORN. When the new concentration level is maintained, it becomes a background concentration and affects the responses of the ON and OFF ORNs to superimposed changes. Raising the background concentration decreases both the ON-ORN's response to concentration jumps and the OFF-ORN's response to concentration drops. In addition, the slopes of the functions approximating the relationship of impulse frequency to concentration changes become flatter for both types of ORNs as the background concentration rises. The progressively compressed scaling optimizes the detection of concentration changes in the low concentration range. The loss of information caused by the lower differential sensitivity in the high concentration range is partially compensated by the higher discharge rates of the OFF ORNs. The functional asymmetry of the ON and OFF ORNs, which reflects nonlinearity in the detection of changes in the concentration of the lemon oil odor, improves information transfer for decrements in the high concentration range.

Sign in / Sign up

Export Citation Format

Share Document