Measurements of Oxygen Partial Pressure and Single-Unit Action Potentials in the Parieto-Visceral Ganglion of Aplysia californica

A preparation was developed that allows for the recording of single-unit chemoreceptor activity from mouse carotid body in vitro. An anesthetized mouse was decapitated, and each carotid body was harvested, along with the sinus nerve, glossopharyngeal nerve, and petrosal ganglia. After exposure to collagenase/trypsin, the cleaned complex was transferred to a recording chamber where it was superfused with oxygenated saline. The ganglia was searched for evoked or spontaneous unit activity by using a glass suction electrode. Single-unit action potentials were 57 ± 10 (SE) ( n = 16) standard deviations above the recording noise, and spontaneous spikes were generated as a random process. Decreasing superfusate[Formula: see text] to near 20 Torr caused an increase in spiking activity from 1.3 ± 0.4 to 14.1 ± 1.9 Hz ( n = 16). The use of mice for chemoreceptor studies may be advantageous because targeted gene deletions are well developed in the mouse model and may be useful in addressing unresolved questions regarding the mechanism of chemotransduction.

Download Full-text

A regenerative microchannel device for recording multiple single-unit action potentials in awake, ambulatory animals

European Journal of Neuroscience ◽

10.1111/ejn.13080 ◽

2015 ◽

Vol 43 (3) ◽

pp. 474-485 ◽

Cited By ~ 14

Author(s):

Akhil Srinivasan ◽

John Tipton ◽

Mayank Tahilramani ◽

Adel Kharbouch ◽

Eric Gaupp ◽

...

Keyword(s):

Action Potentials ◽

Single Unit ◽

Microchannel Device ◽

Unit Action

Download Full-text

Improved estimates of conduction velocity distributions using single unit action potentials.

Journal of Neurology Neurosurgery & Psychiatry ◽

10.1136/jnnp.44.6.476 ◽

1981 ◽

Vol 44 (6) ◽

pp. 476-484 ◽

Cited By ~ 10

Author(s):

T E Milner ◽

R B Stein ◽

J Gillespie ◽

B Hanley

Keyword(s):

Conduction Velocity ◽

Action Potentials ◽

Single Unit ◽

Conduction Velocity Distributions ◽

Unit Action

Download Full-text

CO2 transduction in avian intrapulmonary chemoreceptors is critically dependent on transmembrane Na+/H+ exchange

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00519.2002 ◽

2003 ◽

Vol 284 (6) ◽

pp. R1551-R1559 ◽

Cited By ~ 13

Author(s):

Steven C. Hempleman ◽

Thomas P. Adamson ◽

Rowin S. Begay ◽

Irene C. Solomon

Keyword(s):

Carbonic Anhydrase ◽

Intracellular Ph ◽

Action Potentials ◽

Single Unit ◽

Intrapulmonary Chemoreceptors ◽

Dose Dependent Decrease ◽

Dimethyl Amiloride ◽

Dose Dependent ◽

Unit Action

Avian intrapulmonary chemoreceptors (IPC) are vagal respiratory afferents that are inhibited by high lung Pco 2 and excited by low lung Pco 2. Previous work suggests that increased CO2 inhibits IPC by acidifying intracellular pH (pHi) and that pHi is determined by a kinetic balance between the rate of intracellular carbonic anhydrase-catalyzed CO2 hydration/dehydration and transmembrane extrusion of acids and/or bases by various exchangers. Here, the role of amiloride-sensitive Na+/H+ exchange (NHE) in the IPC CO2 response was tested by recording single-unit action potentials from IPC in anesthetized ducks, Anas platyrhynchos. For each of the IPC tested, blockade of the NHE using dimethyl amiloride (DMA) elicited a marked (>50%) dose-dependent decrease in mean IPC discharge ( P < 0.05), suggesting that NHE is important for pHi regulation and CO2 transduction in IPC. In addition, activation of the NHE using 12-O-tetradecanoylphorbol 13-acetate stimulated six of the seven IPC tested, although the overall effect was not statistically significantly ( P = 0.07). Taken together, these findings suggest that CO2 transduction in IPC is dependent on transmembrane NHE although it is likely to be much slower than carbonic anhydrase-catalyzed hydration-dehydration of CO2.

Download Full-text