Role of CRF in Stress-Related Alterations of Gastric and Colonic Motor Function

1993 ◽  
Vol 697 (1 Corticotropin) ◽  
pp. 233-243 ◽  
Author(s):  
YVETTE TACHÉ ◽  
HUBERT MÖNNIKES ◽  
BRUNO BONAZ ◽  
JEAN RIVIER
Keyword(s):  
1998 ◽  
Vol 275 (3) ◽  
pp. G498-G505 ◽  
Author(s):  
Einar S. Björnsson ◽  
William D. Chey ◽  
Uri Ladabaum ◽  
Michelle L. Woods ◽  
Forrest G. Hooper ◽  
...  

Colonic motor function is modulated by extended and local neural reflexes involving unknown mediators. To test the role of serotonin (5-HT3) pathways, increases in colonic tone during antral distension and duodenal lipid perfusion (gastrocolonic responses) and changes in orad and caudad colonic tone in response to local colonic distension (peristaltic reflex) were measured after double-blind granisetron (10 μg/kg) or placebo infusion in healthy human volunteers. Antral distension evoked increases in colonic tone, which were blunted by granisetron ( P < 0.05) without effects on antral compliance. Intraduodenal lipid perfusion also evoked increased colonic tone, which was reduced by granisetron ( P < 0.05). In contrast, orad colonic contractions and caudad relaxations and contractions during colonic distension were unaffected by granisetron. In conclusion, 5-HT3 receptor antagonism blunts both the mechano- and chemoreceptor components of the human gastrocolonic response without altering antral compliance. In contrast, 5-HT3 pathways play no role in the ascending or descending components of the colonic peristaltic reflex. These findings demonstrate different roles for 5-HT3 receptors in the control of colonic motor function by the proximal gastrointestinal tract and by local neural reflexes.


2005 ◽  
Vol 2 (3) ◽  
pp. 146-154 ◽  
Author(s):  
Yvette Taché ◽  
Mulugeta Million ◽  
Allyson G. Nelson ◽  
Christophe Lamy ◽  
Lixin Wang

2001 ◽  
Vol 280 (2) ◽  
pp. G173-G177 ◽  
Author(s):  
Yvette Taché ◽  
Vicente Martinez ◽  
Mulugeta Million ◽  
Lixin Wang

Alterations of gastrointestinal (GI) motor function are part of the visceral responses to stress. Inhibition of gastric emptying and stimulation of colonic motor function are the commonly encountered patterns induced by various stressors. Activation of brain corticotropin-releasing factor (CRF) receptors mediates stress-related inhibition of upper GI and stimulation of lower GI motor function through interaction with different CRF receptor subtypes. CRF subtype 1 receptors are involved in the colonic and anxiogenic responses to stress and may have clinical relevance in the comorbidity of anxiety/depression and irritable bowel syndrome.


1993 ◽  
Vol 231 (1) ◽  
pp. 61-68 ◽  
Author(s):  
J.Michael Walker ◽  
Wayne D. Bowen ◽  
Saundra L. Patrick ◽  
Wanda E. Williams ◽  
S.Wayne Mascarella ◽  
...  
Keyword(s):  

1993 ◽  
Vol 236 (3) ◽  
pp. 495
Author(s):  
J.Michael Walker ◽  
Wayne D. Bowen ◽  
Saundra L. Patrick ◽  
Wanda E. Williams ◽  
S.Wayne Mascarella ◽  
...  
Keyword(s):  

2007 ◽  
Vol 292 (1) ◽  
pp. G419-G428 ◽  
Author(s):  
L. Wang ◽  
V. Martínez ◽  
H. Kimura ◽  
Y. Taché

Serotonin [5-hydroxytryptamine (5-HT)] acts as a modulator of colonic motility and secretion. We characterized the action of the 5-HT precursor 5-hydroxytryptophan (5-HTP) on colonic myenteric neurons and propulsive motor activity in conscious mice. Fos immunoreactivity (IR), used as a marker of neuronal activation, was monitored in longitudinal muscle/myenteric plexus whole mount preparations of the distal colon 90 min after an intraperitoneal injection of 5-HTP. Double staining of Fos IR with peripheral choline acetyltransferase (pChAT) IR or NADPH-diaphorase activity was performed. The injection of 5-HTP (0.5, 1, 5, or 10 mg/kg ip) increased fecal pellet output and fluid content in a dose-related manner, with a peak response observed within the first 15 min postinjection. 5-HTP (0.5–10 mg/kg) dose dependently increased Fos expression in myenteric neurons, with a maximal response of 9.9 ± 1.0 cells/ganglion [ P < 0.05 vs. vehicle-treated mice (2.3 ± 0.6 cells/ganglion)]. There was a positive correlation between Fos expression and fecal output. Of Fos-positive ganglionic cells, 40 ± 4% were also pChAT positive and 21 ± 5% were NADPH-diaphorase positive in response to 5-HTP, respectively. 5-HTP-induced defecation and Fos expression were completely prevented by pretreatment with the selective 5-HT4 antagonist RS-39604. These results show that 5-HTP injected peripherally increases Fos expression in different populations of cholinergic and nitrergic myenteric neurons in the distal colon and stimulates propulsive colonic motor function through 5-HT4 receptors in conscious mice. These findings suggest an important role of activation of colonic myenteric neurons in the 5-HT4 receptor-mediated colonic propulsive motor response.


Author(s):  
C. J. Steadman ◽  
S. F. Phillips
Keyword(s):  

2021 ◽  
Vol 12 ◽  
Author(s):  
Ana Dionísio ◽  
Rita Gouveia ◽  
João Castelhano ◽  
Isabel Catarina Duarte ◽  
Gustavo C. Santo ◽  
...  

Objectives: Transcranial magnetic stimulation, in particular continuous theta burst (cTBS), has been proposed for stroke rehabilitation, based on the concept that inhibition of the healthy hemisphere helps promote the recovery of the lesioned one. We aimed to study its effects on cortical excitability, oscillatory patterns, and motor function, the main aim being to identify potentially beneficial neurophysiological effects.Materials and Methods: We applied randomized real or placebo stimulation over the unaffected primary motor cortex of 10 subacute (7 ± 3 days) post-stroke patients. Neurophysiological measurements were performed using electroencephalography and electromyography. Motor function was assessed with the Wolf Motor Function Test. We performed a repeated measure study with the recordings taken pre-, post-cTBS, and at 3 months' follow-up.Results: We investigated changes in motor rhythms during arm elevation and thumb opposition tasks and found significant changes in beta power of the affected thumb's opposition, specifically after real cTBS. Our results are consistent with an excitatory response (increase in event-related desynchronization) in the sensorimotor cortical areas of the affected hemisphere, after stimulation. Neither peak-to-peak amplitude of motor-evoked potentials nor motor performance were significantly altered.Conclusions: Consistently with the theoretical prediction, this contralateral inhibitory stimulation paradigm changes neurophysiology, leading to a significant excitatory impact on the cortical oscillatory patterns of the contralateral hemisphere. These proof-of-concept results provide evidence for the potential role of continuous TBS in the neurorehabilitation of post-stroke patients. We suggest that these changes in ERS/ERD patterns should be further explored in future phase IIb/phase III clinical trials, in larger samples of poststroke patients.


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