ABSTRACT
Rapid Golgi preparations of golden hamster dorsal lateral geniculate nucleus (LGd)show three classes of neurons with different morphological characteristics. Class Ⅰ and class Ⅲ cells are distributed throughout the LGd.Class Ⅱ cells are found more common medially at mid-genieulate levels.Class Ⅰ cells are multipolar neurons with large cell body.The smooth primary dendrites branch extensively. Spine-like and small excrescences are found along distal dendrites.Class Ⅱ cells have medium size pear-like cell body.The distal dendrites are usually derived from one primary dentrite.Dense cluster of dentritic protrusions is usually found at branch points of the dendrites.Class Ⅲ cells have the smallest cell body and are paucidendritie but the dendrites have complex protrusions including pearl-like dendritic appendages.Class Ⅰ and class Ⅱ cells possess an axon but most of class Ⅲ cells are not found to have an axon. The connections between the LGd and visual cortex was investigated using the retrograde horseradish peroxidase(HRP)histochemical method.After injection of HRP into the visual cortex,Class Ⅰ and class Ⅱ neurons were labelled but class Ⅲ celts were not suggesting that class Ⅰ and class Ⅱ cells are projecting neurons.Class Ⅲ cells do not seem to project to the visual cortex and are probably local circuit neurons.