Figure 3.

Immunoreactions found in lamina I of the spinal dorsal horn in control rats showing multiple labellings at the level of the same neurite. Two immunoreactive zones (arrowheads) are present between an axon (A₁) and a dendrite (D), and at the interface between two axons (A₁ and A₂). In both cases, no synaptic differentiation was noted. Labelling is strictly localized to the extracellular space between the two neurites. Scale bars = 500 nm.