Psychoneurogastroenterology: Interrelations in stress-induced colonic motility and behavior

Individual differences in behavioral and physiological response patterns to stress may contribute to vulnerability for stress-related illnesses such a s functional gastrointestinal disorders. Animal models could give clues abo ut specific individual determinants of intestinal reactivity to stress and stress-induced sensitization. Rats fitted with permanent electrodes on the proximal colon were exposed to a single session of foot shocks (10 x 6 s in 15 min, preshocked) or no shocks (control). Two weeks later, the preshocke d group showed a significantly greater colonic spike burst response to a no vel shock-prod stressor in the home cage than controls. The increase in bur st frequency was positively correlated with the duration of active burying of the threatening prod in both experimental groups, but not with other beh avioral components. Basal colonic burst frequency at rest was negatively co rrelated with the increase in burst frequency due to shock-prod stress in b oth groups, but the degree of sensitization in preshocked rats vs. controls was of similar magnitude in rats with low and high basal colonic burst fre quency. The results indicate that colonic responsivity to stress is related to both basal motility status and individual coping strategies. (C) 1999 E lsevier Science Inc.