Neurochemical fingerprinting of amygdalostriatal and intra-amygdaloid projections: a tracing-immunofluorescence study in the rat.

Amygdalostriatal and intra-amygdaloid fiber connectivity was studied in rats via injections of one of the tracers Phaseolus vulgaris leucoagglutinin (PHA-L) or biotinylated dextran amine (BDA) into various amygdaloid nuclei. To determine the neurotransmitter identity of labeled fibers we combined tracer detection with immunofluorescence staining, using antibodies against vesicular transporters (VTs) associated with glutamatergic (VGluT1, VGluT2) or GABAergic (VGAT) neurotransmission. High-magnification confocal laser scanning images were screened for overlap: occurrence inside tracer labeled fibers or axon terminals of immunofluorescence signal associated with one of the VTs.