Fig. 13.

Axosomatic (a–e) and axodendritic (f) synaptic profiles contacting labeled (asterisk) preganglionic motoneurons shown in Fig. 12. Numerous synaptic contacts (arrowheads) were observed on the plasma membrane of the soma (a–e). In addition, the somata often displayed spines of various shapes and lengths (b–e) that were synaptically contacted by terminals. Most axosomatic profiles contained clear spherical vesicles (At1), although some contained scattered dense-core vesicles (small arrow), as well (At1D) (c). At1 and At1D type profiles also predominated on the proximal dendrites (f), but profiles with clear pleomorphic vesicles (At2D) were also observed. Scale bar in d = a–c), e