TY - JOUR
T1 - Differential CO2-induced c-fos gene expression in the nucleus tractus solitarii of inbred mouse strains
AU - Tankersley, Clarke G.
AU - Haxhiu, Musa A.
AU - Gauda, Estelle B.
PY - 2002
Y1 - 2002
N2 - Genetic determinants confer variation between inbred mouse strains with respect to the magnitude and pattern of ventilation during hypercapnic challenge. Specifically, inheritance patterns derived from low-responsive C3H/HeJ (C3) and high-responsive C57BL/6J (B6) mouse strains suggest that differential hypercapnic ventilatory sensitivity (HCVS) is controlled by two independent genes. The present study also tests whether differential neuronal activity in respiratory control regions of the brain is positively associated with strain variation in HCVS. With the use of whole body plethysmography, ventilation was assessed in C3 and B6 strains at baseline and during 30 min of hypercapnia (inspired CO2 fraction = 0.15, inspired O2 fraction = 0.21 in N2). Subsequently, in situ hybridization histochemistry was performed to determine changes in c-fos gene expression in the commissural subnucleus of the nucleus tractus solitarius (NTS). During hypercapnia, breathing frequency and tidal volume were significantly (P < 0.01) different between strains: C3 mice showed a slow, deep-breathing pattern relative to a rapid, shallow phenotype of B6 mice. CO2-induced increase in c-fos gene expression was significantly (P < 0.01) greater in NTS regions of B6 compared with C3 mice. In this genetic model of differential HCVS, the results suggest that a genomic basis for varied hypercapnic chemoreception or transduction confers greater afferent neuronal activity in the caudal NTS for high-responsive B6 mice compared with low-responsive C3 mice.
AB - Genetic determinants confer variation between inbred mouse strains with respect to the magnitude and pattern of ventilation during hypercapnic challenge. Specifically, inheritance patterns derived from low-responsive C3H/HeJ (C3) and high-responsive C57BL/6J (B6) mouse strains suggest that differential hypercapnic ventilatory sensitivity (HCVS) is controlled by two independent genes. The present study also tests whether differential neuronal activity in respiratory control regions of the brain is positively associated with strain variation in HCVS. With the use of whole body plethysmography, ventilation was assessed in C3 and B6 strains at baseline and during 30 min of hypercapnia (inspired CO2 fraction = 0.15, inspired O2 fraction = 0.21 in N2). Subsequently, in situ hybridization histochemistry was performed to determine changes in c-fos gene expression in the commissural subnucleus of the nucleus tractus solitarius (NTS). During hypercapnia, breathing frequency and tidal volume were significantly (P < 0.01) different between strains: C3 mice showed a slow, deep-breathing pattern relative to a rapid, shallow phenotype of B6 mice. CO2-induced increase in c-fos gene expression was significantly (P < 0.01) greater in NTS regions of B6 compared with C3 mice. In this genetic model of differential HCVS, the results suggest that a genomic basis for varied hypercapnic chemoreception or transduction confers greater afferent neuronal activity in the caudal NTS for high-responsive B6 mice compared with low-responsive C3 mice.
KW - C3H/HeJ
KW - C57BL/6J
KW - Control of breathing
KW - Hypercapnic ventilation
KW - Hypoventilation
UR - http://www.scopus.com/inward/record.url?scp=0036092933&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036092933&partnerID=8YFLogxK
U2 - 10.1152/japplphysiol.00609.2001
DO - 10.1152/japplphysiol.00609.2001
M3 - Article
C2 - 11842068
AN - SCOPUS:0036092933
SN - 8750-7587
VL - 92
SP - 1277
EP - 1284
JO - Journal of applied physiology
JF - Journal of applied physiology
IS - 3
ER -