Fig. 5.
GABAergic dendrites are the postsynaptic targets of CR-IR axon terminals in the CA1 and CA3 subfield. A, Three boutons (b1–3) of cell 2 (of Fig. 2) are shown in the light micrograph. B–D, Examination of the three boutons in the electron microscope revealed that they contact the same GABA-positive postsynaptic dendrite. As shown in the two consecutive sections of boutons 1 and 2 (B, C) and of bouton 3 (D), the CR-IR axon terminals formed symmetrical synapses (arrows) with the GABA-containing dendrite (dG). E, F, GABA-positive axon terminal of cell 1 in Figure 2B. The CR-containing axon is shown in two consecutive sections, forming a symmetrical synapse (arrow) on a GABA-positive dendrite (dG) in stratum moleculare. Asterisksand a star mark GABA-negative and GABA-positive elements in the neuropil. Scale bars: A, 10 μm; B–F, 0.5 μm.