Figure 3.

Human bowel afferent sensitivity was altered with age. (A) Representative traces of baseline firing in specimens from a 54‐ and 72‐year‐old donor. (B) Average baseline firing frequency was significantly decreased with age (p < 0.05, linear regression, r ² = 0.304, N = 19). (C) The donor age of the afferent units displaying spontaneous burst firing was significantly lower than that without burst firing (p < 0.001, unpaired t‐test, N = 13 for burst+, N = 23 for burst‐). (D) Number of units recorded was not significantly changed with age (p = 0.489, linear regression, r ² = 0.029, N = 19). (E–H) Afferent responses to bradykinin appeared to be decreased with age in the human sigmoid colon. (E) Representative response to 10 μM bradykinin from a 42‐year‐old donor, (F) Representative response to 10 μM bradykinin from a 55‐year‐old donor, and (G) Representative response to 10 μM bradykinin from a 67‐year‐old donor. (H) Response to bradykinin from preparations from 3 donors. ***denotes significance at p < 0.001.