Figure 4

Schematic illustration of the cholinergic connection between the Ixodes synganglion and salivary gland. (A) The cholinergic axons (red) originating from OsSG neurons exit the synganglion via the opistosomal nerves (OsN) to reach the type I acini exclusively. (B) Schematic detailing the distribution of cholinergic axons (red) within the type I acinus. Note that cholinergic axon terminals within the acinus invaginate between the basolateral infoldings of both peripheral lamellate cells (PLC) and the central lamellate cell (CLC). C circumlumenal cell, PC peritubular cell, E esophagus, OsG opistosomal ganglion. The nomenclature of the acinar cells is after Needman et al.²⁶.