Relationship of calcium-binding protein containing neurons and projection neurons in the rat basolateral amygdala

Two-laser and two-color approaches were used to observe the colocalization of the calcium-binding proteins, calbindin D28k and parvalbumin, and the re trograde tracer, Fluoro-Gold (FG) in the basolateral amygdala of the rat. T he study was performed on five adult rats into which FG was injected to the frontal association cortex. Then, the localization of the retrogradely lab eled neurons in the basolateral amygdala was compared with the localization of the neurons labeled by calcium-binding proteins. The present study show ed that most of the retrogradely labeled neurons in the posterior part of t he basolateral amygdala are also calbindin-positive. Even though a lot of p arvalbumin-positive endings were present at the surface of the retrogradely labeled cells, we did not observe the colocalization of the parvalbumin an d projective neurons. (C) 1999 Elsevier Science Ireland Ltd. All rights res erved.