Fig. 4.

(A) Pre- and postsynaptic markers of chandelier neuron inputs to the axon initial segment of pyramidal neurons. (a and b) Immunoreactivity for GAT1 (a) and parvalbumin (b) clearly identifies vertical arrays of chandelier neuron axon terminals (cartridges) that are located below the cell bodies of unlabelled pyramidal neurons. (c) Immunoreactivity for the GABA_A α2 subunit is localized postsynaptically, in the axon initial segment of pyramidal neurons. From Lewis et al. (2005). (B) Schematic summary of the trajectories of pyramidal neuron axon initial segment and chandelier neuron axon cartridges labeled with different markers across postnatal development in area 46 of monkey DLPFC. Lines for each marker represent the percent maximal value achieved plotted against age in months after birth on a log scale. Arrowheads demarcate the indicated ages in months, and the shaded area indicates the approximate age range corresponding to adolescence in this species.

From Cruz et al. (2009a,b).