Further Evidence of Redox Modulation of Neurons in a CO2-Chemosensitive Area: Normobaric Hyperoxia (95%O2) Stimulates CO2-Chemosensitive and –Insensitive Neurons in the Solitary Complex (SC)

Michael P. Matott; Carol S. Landon; Robert W. Putnam; Jay B. Dean

Further Evidence of Redox Modulation of Neurons in a CO₂-Chemosensitive Area: Normobaric Hyperoxia (95%O₂) Stimulates CO₂-Chemosensitive and –Insensitive Neurons in the Solitary Complex (SC)

Michael P. Matott, Carol S. Landon, Robert W. Putnam, Jay B. Dean

Wright State University

Research output: Other contribution

Abstract

We previously reported that CO ₂ -excited neurons in SC, in medullary slices maintained in 95%O ₂ , are stimulated by chemical oxidants and hyperbaric O ₂ (JAP 95:910-921, 2003; AJP 286:C940–951, 2004). Here we test the hypothesis that SC neurons, maintained in 40%O ₂ rather than 95%O ₂ (to reduce oxidative stress), are viable and stimulated by normobaric hyperoxia (95%O ₂ ). Slices (P1–21) were harvested in chilled ACSF gassed with 95%O ₂ and immediately transferred to ACSF (22–24°C) equilibrated with 40%O ₂ -5%CO ₂ in N ₂ . Whole cell recordings (35–37°C) were established in 40%O ₂ (n=44) and tested using hyperoxia (4095%O ₂ ) and hypercapnia (510 or 15%CO ₂ ). Hyperoxia stimulated 8/44 neurons and hypercapnia stimulated 5/44 neurons; of these 4/8 were stimulated by both O ₂ and CO ₂ . Hyperoxia usually increased firing rate and decreased input resistance whereas hypercapnia increased firing rate and input resistance. Most neurons tested were insensitive to hyperoxia and hypercapnia (31/44). Compared to previous slice studies that used 95%O ₂ control, there is a smaller proportion of CO ₂ -excited SC neurons in slices maintained in 40%O ₂ . These data indicate that medullary slices are viable in 40%O ₂ and that hyperoxic stress stimulates SC neurons, including CO ₂ -excited neurons. These data also suggest that oxidative stimuli increases the incidence of CO ₂ -chemosensitivity in SC neurons (ONR N000140110179, NIH R01HL56683).

Original language	American English
State	Published - Apr 1 2010

Disciplines

Medical Cell Biology
Medical Neurobiology
Medical Physiology
Medical Sciences
Medicine and Health Sciences
Neurosciences
Physiological Processes

Cite this

@misc{ce6048a9b93146c9a9b1e600313f6334,

title = "Further Evidence of Redox Modulation of Neurons in a CO2-Chemosensitive Area: Normobaric Hyperoxia (95%O2) Stimulates CO2-Chemosensitive and –Insensitive Neurons in the Solitary Complex (SC)",

abstract = " We previously reported that CO 2 -excited neurons in SC, in medullary slices maintained in 95%O 2 , are stimulated by chemical oxidants and hyperbaric O 2 (JAP 95:910-921, 2003; AJP 286:C940–951, 2004). Here we test the hypothesis that SC neurons, maintained in 40%O 2 rather than 95%O 2 (to reduce oxidative stress), are viable and stimulated by normobaric hyperoxia (95%O 2 ). Slices (P1–21) were harvested in chilled ACSF gassed with 95%O 2 and immediately transferred to ACSF (22–24°C) equilibrated with 40%O 2 -5%CO 2 in N 2 . Whole cell recordings (35–37°C) were established in 40%O 2 (n=44) and tested using hyperoxia (4095%O 2 ) and hypercapnia (510 or 15%CO 2 ). Hyperoxia stimulated 8/44 neurons and hypercapnia stimulated 5/44 neurons; of these 4/8 were stimulated by both O 2 and CO 2 . Hyperoxia usually increased firing rate and decreased input resistance whereas hypercapnia increased firing rate and input resistance. Most neurons tested were insensitive to hyperoxia and hypercapnia (31/44). Compared to previous slice studies that used 95%O 2 control, there is a smaller proportion of CO 2 -excited SC neurons in slices maintained in 40%O 2 . These data indicate that medullary slices are viable in 40%O 2 and that hyperoxic stress stimulates SC neurons, including CO 2 -excited neurons. These data also suggest that oxidative stimuli increases the incidence of CO 2 -chemosensitivity in SC neurons (ONR N000140110179, NIH R01HL56683).",

author = "Matott, {Michael P.} and Landon, {Carol S.} and Putnam, {Robert W.} and Dean, {Jay B.}",

year = "2010",

month = apr,

day = "1",

language = "American English",

type = "Other",

}

TY - GEN

T1 - Further Evidence of Redox Modulation of Neurons in a CO2-Chemosensitive Area: Normobaric Hyperoxia (95%O2) Stimulates CO2-Chemosensitive and –Insensitive Neurons in the Solitary Complex (SC)

AU - Matott, Michael P.

AU - Landon, Carol S.

AU - Putnam, Robert W.

AU - Dean, Jay B.

PY - 2010/4/1

Y1 - 2010/4/1

N2 - We previously reported that CO 2 -excited neurons in SC, in medullary slices maintained in 95%O 2 , are stimulated by chemical oxidants and hyperbaric O 2 (JAP 95:910-921, 2003; AJP 286:C940–951, 2004). Here we test the hypothesis that SC neurons, maintained in 40%O 2 rather than 95%O 2 (to reduce oxidative stress), are viable and stimulated by normobaric hyperoxia (95%O 2 ). Slices (P1–21) were harvested in chilled ACSF gassed with 95%O 2 and immediately transferred to ACSF (22–24°C) equilibrated with 40%O 2 -5%CO 2 in N 2 . Whole cell recordings (35–37°C) were established in 40%O 2 (n=44) and tested using hyperoxia (4095%O 2 ) and hypercapnia (510 or 15%CO 2 ). Hyperoxia stimulated 8/44 neurons and hypercapnia stimulated 5/44 neurons; of these 4/8 were stimulated by both O 2 and CO 2 . Hyperoxia usually increased firing rate and decreased input resistance whereas hypercapnia increased firing rate and input resistance. Most neurons tested were insensitive to hyperoxia and hypercapnia (31/44). Compared to previous slice studies that used 95%O 2 control, there is a smaller proportion of CO 2 -excited SC neurons in slices maintained in 40%O 2 . These data indicate that medullary slices are viable in 40%O 2 and that hyperoxic stress stimulates SC neurons, including CO 2 -excited neurons. These data also suggest that oxidative stimuli increases the incidence of CO 2 -chemosensitivity in SC neurons (ONR N000140110179, NIH R01HL56683).

AB - We previously reported that CO 2 -excited neurons in SC, in medullary slices maintained in 95%O 2 , are stimulated by chemical oxidants and hyperbaric O 2 (JAP 95:910-921, 2003; AJP 286:C940–951, 2004). Here we test the hypothesis that SC neurons, maintained in 40%O 2 rather than 95%O 2 (to reduce oxidative stress), are viable and stimulated by normobaric hyperoxia (95%O 2 ). Slices (P1–21) were harvested in chilled ACSF gassed with 95%O 2 and immediately transferred to ACSF (22–24°C) equilibrated with 40%O 2 -5%CO 2 in N 2 . Whole cell recordings (35–37°C) were established in 40%O 2 (n=44) and tested using hyperoxia (4095%O 2 ) and hypercapnia (510 or 15%CO 2 ). Hyperoxia stimulated 8/44 neurons and hypercapnia stimulated 5/44 neurons; of these 4/8 were stimulated by both O 2 and CO 2 . Hyperoxia usually increased firing rate and decreased input resistance whereas hypercapnia increased firing rate and input resistance. Most neurons tested were insensitive to hyperoxia and hypercapnia (31/44). Compared to previous slice studies that used 95%O 2 control, there is a smaller proportion of CO 2 -excited SC neurons in slices maintained in 40%O 2 . These data indicate that medullary slices are viable in 40%O 2 and that hyperoxic stress stimulates SC neurons, including CO 2 -excited neurons. These data also suggest that oxidative stimuli increases the incidence of CO 2 -chemosensitivity in SC neurons (ONR N000140110179, NIH R01HL56683).

UR - https://corescholar.libraries.wright.edu/ncbp/778

M3 - Other contribution

ER -

Further Evidence of Redox Modulation of Neurons in a CO2-Chemosensitive Area: Normobaric Hyperoxia (95%O2) Stimulates CO2-Chemosensitive and –Insensitive Neurons in the Solitary Complex (SC)

Abstract

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Further Evidence of Redox Modulation of Neurons in a CO₂-Chemosensitive Area: Normobaric Hyperoxia (95%O₂) Stimulates CO₂-Chemosensitive and –Insensitive Neurons in the Solitary Complex (SC)