Figure 1. Dissociated pyramidal cells of CA3 with fluorescent giant MFBs attached to their apical dendrites.

A, prior to dissociation, Zn²⁺-containing MFBs are labelled with the fluorescent sensor for Zn²⁺, Zinpyr-1, or (Ba and b) with dextranamine transported from the granule cell layer to the MFs terminals. C, enzyme-free mechanical dissociation is then conducted using a vibrating blunt pipette positioned over CA3 with a micromanipulator. MFBs can be identified attached to the apical dendrites of the dissociated pyramidal cells by their fluorescent label of either Zinpyr-1 (Da and b) or rhodamine-dextranamine (Ea and b). Other non-fluorescent bulks (putative boutons) can also be observed (arrowhead, IntB in Da and b), which can be electrophysiologically verified. F, pyramidal cells and G, interneurons are recognized by their characteristic shape and firing of action potentials on depolarization.