Abstract
Unitary discharges were recorded from the inferior mesenteric ganglion of decerebrate dogs. Eighty-one units were identified as sympathetic postganglionic neurons innervating the colon and rectum by collision test performed by stimulation of the lumbar colonic nerve. Discharges of four units were enhanced simultaneously with an increased outflow of the renal nerve by pinching a toe. Thus, those units were regarded as vasoconstrictors of colonic blood vessels. Sixty-five units whose discharges were depressed or not affected by the pinching were regarded as neurons innervating colonic smooth muscle or mucosa (colonic units). Discharges were enhanced in the majority of the colonic units by colonic, rectal, and vesical distension, and mechanical stimulation of the anal canal, while discharges were depressed in a few units by rectal and vesical distension, and the anal canal stimulation. The number and percentage of the depressed units increased not only after cutting the hypogastric nerves and descending branches of the lumbar colonic nerve but also after transection of the caudal pons. The reflex depressions disappeared after transection at the bulbospinal junction, but the reflex enhancements remained. These results indicate that the colonic units are enhanced through a spinal reflex by the inflows from the distal colon, rectum, anal canal, and urinary bladder through the lumbar colonic, hypogastric, pelvic, and pudendal nerves, while a few are inhibited through a supraspinal reflex by inflows through the pelvic and pudendal nerves.
| Original language | English |
|---|---|
| Pages (from-to) | 223-241 |
| Number of pages | 19 |
| Journal | The Japanese Journal of Physiology |
| Volume | 37 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 1987 |
| Externally published | Yes |
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Keywords
- autonomic reflex
- colon
- defecation
- inferior mesenteric ganglion
- sympathetic postganglionic neuron
ASJC Scopus subject areas
- Physiology
Cite this
Reflex Responses of Neurons in the Inferior Mesenteric Ganglion to Mechanical Stimulation of the Colon, Rectum, Anal Canal, and Urinary Bladder in the Dog. / Fukuda, Hiroyuki; Fukai, Kiyoko; Okada, Hiromasa.
In: The Japanese Journal of Physiology, Vol. 37, No. 2, 1987, p. 223-241.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Reflex Responses of Neurons in the Inferior Mesenteric Ganglion to Mechanical Stimulation of the Colon, Rectum, Anal Canal, and Urinary Bladder in the Dog
AU - Fukuda, Hiroyuki
AU - Fukai, Kiyoko
AU - Okada, Hiromasa
PY - 1987
Y1 - 1987
N2 - Unitary discharges were recorded from the inferior mesenteric ganglion of decerebrate dogs. Eighty-one units were identified as sympathetic postganglionic neurons innervating the colon and rectum by collision test performed by stimulation of the lumbar colonic nerve. Discharges of four units were enhanced simultaneously with an increased outflow of the renal nerve by pinching a toe. Thus, those units were regarded as vasoconstrictors of colonic blood vessels. Sixty-five units whose discharges were depressed or not affected by the pinching were regarded as neurons innervating colonic smooth muscle or mucosa (colonic units). Discharges were enhanced in the majority of the colonic units by colonic, rectal, and vesical distension, and mechanical stimulation of the anal canal, while discharges were depressed in a few units by rectal and vesical distension, and the anal canal stimulation. The number and percentage of the depressed units increased not only after cutting the hypogastric nerves and descending branches of the lumbar colonic nerve but also after transection of the caudal pons. The reflex depressions disappeared after transection at the bulbospinal junction, but the reflex enhancements remained. These results indicate that the colonic units are enhanced through a spinal reflex by the inflows from the distal colon, rectum, anal canal, and urinary bladder through the lumbar colonic, hypogastric, pelvic, and pudendal nerves, while a few are inhibited through a supraspinal reflex by inflows through the pelvic and pudendal nerves.
AB - Unitary discharges were recorded from the inferior mesenteric ganglion of decerebrate dogs. Eighty-one units were identified as sympathetic postganglionic neurons innervating the colon and rectum by collision test performed by stimulation of the lumbar colonic nerve. Discharges of four units were enhanced simultaneously with an increased outflow of the renal nerve by pinching a toe. Thus, those units were regarded as vasoconstrictors of colonic blood vessels. Sixty-five units whose discharges were depressed or not affected by the pinching were regarded as neurons innervating colonic smooth muscle or mucosa (colonic units). Discharges were enhanced in the majority of the colonic units by colonic, rectal, and vesical distension, and mechanical stimulation of the anal canal, while discharges were depressed in a few units by rectal and vesical distension, and the anal canal stimulation. The number and percentage of the depressed units increased not only after cutting the hypogastric nerves and descending branches of the lumbar colonic nerve but also after transection of the caudal pons. The reflex depressions disappeared after transection at the bulbospinal junction, but the reflex enhancements remained. These results indicate that the colonic units are enhanced through a spinal reflex by the inflows from the distal colon, rectum, anal canal, and urinary bladder through the lumbar colonic, hypogastric, pelvic, and pudendal nerves, while a few are inhibited through a supraspinal reflex by inflows through the pelvic and pudendal nerves.
KW - autonomic reflex
KW - colon
KW - defecation
KW - inferior mesenteric ganglion
KW - sympathetic postganglionic neuron
UR - http://www.scopus.com/inward/record.url?scp=0023083113&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023083113&partnerID=8YFLogxK
U2 - 10.2170/jjphysiol.37.223
DO - 10.2170/jjphysiol.37.223
M3 - Article
C2 - 3626178
AN - SCOPUS:0023083113
VL - 37
SP - 223
EP - 241
JO - Journal of Physiological Sciences
JF - Journal of Physiological Sciences
SN - 1880-6546
IS - 2
ER -