Figure 2.

Injection of biotinylated dextran amine (BDA) into the gustatory responsive waist region of the parabrachial nucleus labels ascending projection neurons in the rostrocentral nucleus of the solitary tract (rNTS). (A) BDA injection using the same coordinates as the recording site in Figure 1 produces Golgi-like retrograde cellular filling in the rNTS (BDA reacted with stretavidin-Alexa488). Such an injection labels both multipolar and elongate neurons as viewed in both the (B) low power tracing of each neuron and (C) high power collapsed confocal z-stack (e = elongate neuron, m = multipolar neuron) and (D) corresponding wire-diagrams. (E) In the coronal plane, BDA visualized with an ABC-DAB reaction, retrogradely filled neurons are most concentrated in the rostrocentral subdivision (borders drawn from adjacent Nissl- and myelin-stained sections). (F) The majority of labeled neurons extend dendrites in the horizontal plane, parallel to the orientation of the solitary tract (red line). This polar histogram is composed of the dendritic lengths of all dendrites from 44 reconstructed neurons. Scale in A and B = 250 μm. Scale in C = 100 μm. Scale in E = 200 μm. D = Dorsal, L = Lateral, R = Rostral. RC = Rostrocentral subdivision, RL = Rostrolateral subdivision, V = Ventral subdivision.