Fig. 9
ACC-spinal cord projecting fibers and terminals connected with SDH neurons. a–b One Alexa-488-labeled PHA-L-IR fiber (for PHA-L injected into the contralateral side of ACC) made close connection with one cy3 re-stained FG-labeled spinal lamina I neuron (for FG injection into the contralateral PBN) (a) or two cy3-labeled GAD67-IR neurons in spinal lamina II (b). c One DAB stained PHA-L containing axon (A1) made asymmetric synapses with two HRP-labeled dendritic spines (D1, 2), noting that the axon terminal mainly contained round and clear vesicles. An immunonegative axon (A2) also made symmetric synapse with D1, noting the axon terminal mainly contained flat and clear vesicles. d One PHA-L containing axon made symmetric synapse with one HRP-labeled soma (S). e–f One PHA-L containing axon made asymmetric synapses with one nanogold-labeled GAD67-IR (e) or immunonegative dendritic spine (f). Arrows in a–b indicate the close connection sites, in c–d indicate the symmetric synapses. Triangles point to the asymmetric synaptic regions. Bars equal to 10 µm in a–b, 200 nm in c–f
