Figure 7. Quantified 5-HT and TH connections to jejunal neurones.

A, mean numbers of 5-HT-IR varicosities apposed to NOS-IR cell bodies were significantly larger in C57Bl/6 mice. B, this difference is reflected in the frequency distribution of appositions per NOS-IR neurone. C, calretinin-IR cell bodies in C57Bl/6 mice were apposed by significantly greater numbers of 5-HT-IR varicosities than Balb/c. D, frequency distribution of appositions per neurone revealed a trend for more calretinin-IR cell bodies in Balb/c than C57Bl/6 mice not to be apposed by 5-HT-IR varicosities, while larger numbers of varicosities tended to be observed apposing calretinin-IR neurones from C57Bl/6 mice. E, Dogiel type II (DII) and non-Dogiel type II (other) calretinin-IR neurones were apposed by 5-HT-IR varicosities in both strains. Calretinin-IR neurones of both morphologies in C57Bl/6 mice tended to be apposed by larger numbers of 5-HT varicosities than neurones in Balb/c mice, but this only reached significance in non-Dogiel type II neurones. F, the proportion of Dogiel type II neurones that were apposed by no 5-HT varicosities was higher in Balb/c than C57Bl/6 mice, and the maximum number of varicosities apposed to a Dogiel type II neurone from Balb/c mice (8) was lower than the maximum in C57Bl/6 mice (18). G, the proportion of non-Dogiel type II neurones that were apposed by no. 5-HT varicosities was also larger in Balb/c than C57Bl/6 mice. H, mean numbers of 5-HT- and TH-IR varicosities apposed to each cell body were similar between and within strains. *P < 0.05; †P < 0.01 between strains.