[Sparsely-spined neurons in the rat visual cortex]

Sparsely spined neurons were described in the visual cortex of the rat. A large cell type was found in all laminae, but mainly in L III-L V. The soma is large and the dendrites are vertically oriented. In most cases, the axon originates from the upper main dendrite or the upper soma pole. The axonal arborization is vertical. In the terminal axonal segments the number of boutons is high. A small neuron type could be demonstrated in L IV. The soma is small, and the dendritic field is nearly multipolarly or horizontally oriented. The axon derives from the basal pole or laterally at the soma.