TY - JOUR
T1 - Nuclear Fos immunoreactivity in guinea pig myenteric neurons following activation of motor activity
AU - Ritter, Robert C.
AU - Costa, Marcello
AU - Brookes, Simon H.
PY - 1997/10/13
Y1 - 1997/10/13
N2 - To identify enteric neurons activated during intestinal motor activity, we examined myenteric plexus of guinea pig small intestinal segments for expression of the immediate early gene product, Fos. Fos immunoreactivity was detected immunohistochemically following in vitro manipulations, which included distension, electrical stimulation, exposure to forskolin, and peristalsis. All of these manipulations induced neuronal Fos expression, which was prevented by tetrodotoxin, indicating that expression depended on nerve activity. Distension-induced Fos expression was blocked by ω-conotoxin and significantly reduced by hexamethonium, indicating that neurons expressing Fos immunoreactivity were activated synaptically. Blocking smooth muscle contraction with nicardipine reduced expression of neuronal Fos, suggesting that muscle tone influences neuronal activity. Calbindin- immunoreactive putative sensory neurons did not express Fos during distension, peristalsis, or exposure to forskolin and expressed Fos only weakly after strong electrical stimulation. Conversely, calretinin- immunoreactive ascending excitatory interneurons and longitudinal muscle motoneurons exhibited Fos immunoreactivity after all experimental manipulations. These results indicate that Fos expression can, with some caution, be used to identify classes of enteric neurons activated by different stimuli under various experimental conditions.
AB - To identify enteric neurons activated during intestinal motor activity, we examined myenteric plexus of guinea pig small intestinal segments for expression of the immediate early gene product, Fos. Fos immunoreactivity was detected immunohistochemically following in vitro manipulations, which included distension, electrical stimulation, exposure to forskolin, and peristalsis. All of these manipulations induced neuronal Fos expression, which was prevented by tetrodotoxin, indicating that expression depended on nerve activity. Distension-induced Fos expression was blocked by ω-conotoxin and significantly reduced by hexamethonium, indicating that neurons expressing Fos immunoreactivity were activated synaptically. Blocking smooth muscle contraction with nicardipine reduced expression of neuronal Fos, suggesting that muscle tone influences neuronal activity. Calbindin- immunoreactive putative sensory neurons did not express Fos during distension, peristalsis, or exposure to forskolin and expressed Fos only weakly after strong electrical stimulation. Conversely, calretinin- immunoreactive ascending excitatory interneurons and longitudinal muscle motoneurons exhibited Fos immunoreactivity after all experimental manipulations. These results indicate that Fos expression can, with some caution, be used to identify classes of enteric neurons activated by different stimuli under various experimental conditions.
KW - c-fos
KW - Cellular oncogenes
KW - Enteric neurons
KW - Immediate early genes
KW - Intestinal peristalsis
KW - Myenteric plexus
UR - http://www.scopus.com/inward/record.url?scp=0030846704&partnerID=8YFLogxK
U2 - 10.1152/ajpgi.1997.273.2.G498
DO - 10.1152/ajpgi.1997.273.2.G498
M3 - Article
C2 - 9277431
AN - SCOPUS:0030846704
SN - 0193-1857
VL - 273
SP - G498-G507
JO - American Journal of Physiology: Gastrointestinal and Liver Physiology
JF - American Journal of Physiology: Gastrointestinal and Liver Physiology
IS - 2
ER -