-methyl-D-aspartate receptors

Chronic abdominal discomfort and pain are often associated with inflammatory conditions of the gut such as Crohn's disease and functional disorders, for example irritable bowel syndrome. These patients appear to have inappropriate perception of physiological events and altered reflex responses in different gut regions, but the mechanism involved in the nociceptive mechanical transduction remain elusive.

In June Gastroenterology James McRoberts and colleagues from the University of California, Los Angeles, describe the involvement of peripheral N-methyl-D-aspartate (NMDA) receptors in mediating the behavioural pain response to colonic distention in the normal rat colon.

NMDA receptors have an important role in long-term potentiation and memory processing in the central nervous system. McRoberts et al., found that immunohistochemical staining localized the NDMA receptor to the cell bodies and peripheral terminals of primary afferent nerves innervating the colon. Activation of these peripheral NMDA receptors resulted in Ca²⁺-dependent release of the...