A study of neuronal types in clarke's column in the adult cat

Publisher Website
Google Scholar
Abstract
Three neuronal classes have been identified in Clarke's column in the adult cat. The smallest cells (class A) exhibit variable dendritic branching patterns. Medium‐sized neurons (class B) can be subdivided into multipolar and fusiform cells. The majority of the multipolar cells have elongated perikarya and their dendrites project in a radial fashion, while the fusiform neurons often have their long axis perpendicularly oriented. The large Clarke cells (class C) and their dendrites project in the cranio‐caudal direction. Their dendrites are generally smooth and often extend for over 1000 μ from the perikaryon, but three types of dendritic specializations have been noted: spines, branchlets and varicosities. These specializations are not strictly restricted to Clarke cells. Dendrites of all three cell types cross the nuclear boundaries. Some enter the dorsal columns via Rexed's lamina V and others enter laminae VI, VII and X.Neurons whose cell bodies lie within laminae V, VI, VII and X occasionally send dendrites into Clarke's column.Class A cells account for at least 60% of the total neuronal population of Clarke's column and outnumber the Clarke cells (class C) by approximately three to one. Class B neurons are the least common and form between 6 and 16% of the population.