Immunohistohemical staining of transversal colonic sections labelled for ChAT (A, B), SP (C, D) and VIP (E, F).

<p>The same detail of one section is shown in (A), (C) and (E) and in (B), (D) and (F), respectively. Neuronal fibres projecting from an ISP ganglion into the mucosa are immunoreactive for ChAT, SP and VIP (indicated by an arrow in A, C and E). The arrowhead marks a nerve fibre (bundle) not immunoreactive for ChAT (A), but weakly for SP (C) and strongly for VIP (E). (B), (D) and (F) show a nerve fibre bundle (marked by an asterisk) projecting between an OSP ganglion and a ganglion of the MP, expressing immunoreactivity for ChAT (B), SP (D) and VIP (F). Additionally, some fibres (arrow) running from OSP into the circular muscle layer are visible. Scale bar = 50 μm.