[Neurons forming striatonigral connections in the rat brain]

Using the retrograde axonic transport of horseradish peroxidase method the striatal neurons projections to substance nigra have been studied in rats. After peroxidase injection into substance nigra a considerable number of small and medium sized neurons (10-20 mkm) become labelled in the ipsilateral striatum. Large labelled striatal cells (20-25 mkm) have been found. Among labelled striatal neurons multipolar cells with triangular and oval body prevailed. The number of cells with elongated multipolar or spindle-shaped body was less. The data obtained disprove the conception that only large ("giant") neurons form the efferent striatal pathways to substance nigra.