TRPA1 Channel Activation Inhibits Motor Activity in the Mouse Colon.

There is a growing awareness of the role that TRP channels play in regulating sensory and motor functions in the gastrointestinal tract. In this study we used an in-vitro murine model of colonic peristaltic-like complexes (CPMCs) to evaluate the role of exogenous and endogenous TRPA1 signaling processes in regulating colonic motility. Using in-vitro recordings of intraluminal pressure to monitor the presence of CPMCs in colonic segments we performed a series of experiments on male CD1 mice (2 months of age) and found that CPMC activity was attenuated by TRPA1 agonists. Bath application of the TRPA1 antagonist HC-030031 had no effect upon basal CPMC activity whereas application of the synthetic TRPA1 agonist ASP7663 caused a reversible dose dependent decrease in CPMC frequency that was blocked by HC-030031. Cinnamaldehyde and 4-hydroxy-2-nonenal elicited long lasting decreases in CPMC frequency that were blocked by HC-030031 whereas the decreased CPMC activity invoked by AITC could not be blocked by HC-030031. Our results show that any potential mechanosensory function of TRPA1 doesn't involve contributing to distension induced colonic motor activity and that a role for TRPA1 in the colon is through regulating motility through exogenous and endogenous agonist induced inhibitory effects.

Preferences regarding targeted education and risk assessment in people with a family history of major depressive disorder.

Genetic testing for susceptibility to major depressive disorder (MDD) is not available for clinical use at present. Given this, family history remains the best predictor for development of MDD, and family-history-based risk assessment and information about familial aspects of MDD may be useful to clients at increased risk for MDD attending for genetic counseling. This study uses a mixed-methods design to assess the information needs and preferences of people at increased familial risk for MDD. Telephone interviews were conducted with 23 individuals, who had at least one first-degree relative with MDD and were recruited through advertisements placed on depression education websites. The most preferred way to access depression information was via the internet (87 % of participants), although this preference may have been due to the internet-based recruitment method. The second most preferred dissemination strategy (56 %) was face-to-face delivery through a health professional, including genetic counselors. Individuals reported a need for information about etiology and development of MDD, reproductive decision-making, early detection of symptoms and risk-reducing strategies. Nearly all participants expressed an interest in risk assessment. The present study found evidence of a high level of interest for information targeted to people at increased familial risk for MDD. Genetic counselors are likely to be called upon increasingly to provide supportive counseling to assist clients at increased familial risk in interpreting and contextualizing such information once it becomes available.