Assessment of Visceral Pain-Related Pseudo-Affective Responses to Colorectal Distension in Mice by Intracolonic Manometric Recordings

Modulation of Visceral Pain by Stress: Implications in Irritable Bowel Syndrome

“…We found an excellent correlation between signals from ICP and EMG during consecutive ascending phasic distensions between 15 to 60 mmHg when recorded simultaneously in the same mice. We also showed that the colonic pain pressure threshold to CRD detected by both methods were similar (about 32 mmHg), and consistent with values previously reported using EMG and manometry (Arvidsson et al, 2006;Kamp et al, 2003). As colonic pressure could be altered following abdominal contractions and/or contractions of the colonic wall, we assessed the effects of atropine, a muscarinic blocker known to inhibit colonic motility ), on the VMR to CRD monitored by ICP in naïve mice (Larauche et al, 2010).…”

“…A recent report suggests that the preconditions of animals (EMG surgery, post-surgical delivery of antibiotic and single housing) have a considerable impact on the visceral pain responses to CRD, particularly in the context of stress studies (Larauche et al, 2010). Other approaches consist of recording manometric changes in the pressure of the balloon inserted into the distal colon (Arvidsson et al, 2006) or changes in pressure inside the colonic lumen Larauche et al, 2010). These two techniques present the advantage of being minimally invasive as they do not require surgery and post-surgical treatments such as antibiotics or analgesics which can affect the visceral pain responses and still remain an objective and sensitive measure of abdominal contractions.…”

“…Briefly, a PE50 catheter was taped 2 cm below the pressure sensor of a miniaturized pressure transducer catheter (SPR-524 Mikro-Tip catheter; Millar Instruments, Houston, TX). A custom-made balloon (1-cm width x 2-cm length) (Arvidsson et al, 2006;Christianson & Gebhart, 2007;Kamp et al, 2003) prepared from a polyethylene plastic bag was tied over the catheter at 1 cm below the pressure sensor with silk 4.0. Ligature points were covered with parafilm to prevent any air from leaking.…”

CB1Receptors Mediate the Analgesic Effects of Cannabinoids on Colorectal Distension-Induced Visceral Pain in Rodents

“…In mice, the CRD paradigm used consisted on repeated noxious phasic distensions, 12 times at 55 mmHg, with a pulse duration of 10 s at 5 min intervals. Similar CRD paradigms have been used previously to assess pain-related responses in mice and rats (Tammpere et al, 2005;Arvidsson et al, 2006;Martinez and Melgar, 2008).…”

“…Responses to CRD were assessed by recording and quantitation of phasic changes in intraballoon pressure during the distending pulses, as previously described (Tammpere et al, 2005;Arvidsson et al, 2006). Pressure oscillations during the isobaric inflation of the intracolonic balloon reflect abdominal muscle contractions associated to the distension procedure and, therefore, are considered a valid assessment of the visceromotor response associated to the presence of pain of visceral origin (Tammpere et al, 2005;Arvidsson et al, 2006).…”