Fig. 4.

A,C: Calbindin was not detected in most pretectal cells labeled by the retrograde transport of tracers injected into the PUL. A: A merged photograph of the PT photographed with blue light to reveal PT-PUL cells (green fluorescent microspheres [GFM]) and green light to reveal cells labeled with a calbindin antibody (yellow/ red). C: A photomicrograph of a PT-PUL cell (black crystalline reaction product) in tissue subsequently stained for calbindin (homogenous brown reaction product). B: Glutamic acid decarboxylase (GAD) was not detected in PT-PUL cells. Shown is a merged photograph of the PT photographed with blue light to reveal PT-PUL cells (GFM) and green light to reveal cells labeled with a GAD antibody (red). D–F: γ-Aminobutyric acid (GABA) was detected in a subset of PT-PUL cells. Shown are photomicrographs of PT-PUL cells (black crystalline reaction product) in tissue subsequently stained for GABA (homogenous brown reaction product). For abbreviations, see list. Scale bars = 100 μm in A,B; 30 μm in C (applies to C–F).