Acetylcholinesterase-containing neurons in cat pallidal complex; morphological characteristics and projection towards...

The cat globus pallidus (GP) was found to contain both small and large cells that stain lightly and intensely for acetylcholinesterase (AChE), respectively. The small GP cells are similar to entopeduncular (EN) cells and it is proposed that both should be considered as 'typical' pallidal neurons. In contrast, large GP cells are similar to intensely stained AChE cells present in the substantia innominata (SI) and the putamen (PUT). Furthermore, HRP injection into the neocortex was found to label numerous large AChE cells in GP and a lesser number of similar neurons in PUT and SI. No HRP labeling was observed in the smaller cells of EN, GP and PUT. These findings suggest that the magnocellular AChE neurons in feline basal ganglia may be part of a single population of 'limbic' elements.