The myenteric plexus of ileum in 5 male or female wistar rats weighing 180-220g were studied by histochemical method for acetylcholinesterase (AChE)and nitric oxide synthase (NOS). We found that some neurons in myenteric plexus were located against the capillary or even closely contacted with the capillary. We refer them as pericapillary neurons The neurons were spindle, pear-like or polygonal in shape and all showed NOS positive reaction but AChE negative reaction. According to the close appositional relationship between the neurons and capillary, we infer that this peculiar type of neurons might be similar to the cerebrospinal fluid-contacting neurons in the central nervous system and might have the function of neurosecretion or reception of the changes of chemical composition in the blood.
