title: Types of neurons in nucleus gracilis and nucleus cuneatus of the European bison.
abstract: The study was carried out on the medullae oblongatae of four European bisons. Preparations were made according to the Nissl, Klüver-Barrera and Golgi methods. Nucleus gracilis and nucleus cuneatus of the European bison are formed of 4 types of neurons. Type I--triangular cells. The perikaryon issues 3 dendrites bifurcating once or twice. The dendritic field is ball-shaped. A single thin axon emerges directly from the soma. Tiny granules of the tigroidal substance are very densely distributed and penetrate into the initial segments of dendrites. Type II--multipolar cells. These neurons have 7-9 thick dendrites which bifurcate twice. The dendritic field is ball-shaped. A single axon, 2 microns thick, emerges directly from the perikaryon. The cells contain thick spherical granules of the tigroidal substance. Type III--fusiform cells. From both poles of the perikaryon 2-3 thick dendrites originate which first bifurcate and next give off 2-3 branches. At each pole of the cell there is a separate dendritic field having a stream-like form. The axon arises from the lateral surface of the perikaryon. The tigroidal substance has a form of elongate bands. Type IV--rounded cells. Three thick dendrites are concentrated at one pole of the cell. The dendrites give off collaterals and ramify. The dendritic field has a stream-like form. The axon emerges from the perikaryon, a long distance from the dendrites. Thick granules of the tigroidal substance are evenly distributed in the cell.
authors.affiliation: Department of Vertebrates Anatomy, Teachers Training College, Olsztyn, Poland.
authors.forename: S
authors.initials: S
authors.lastname: Szteyn
authors.forename: A
authors.initials: A
authors.lastname: Robak
mesh_terms: D000818:Animals; D001188:Artiodactyla / Q000033:anatomy & histology*; D008526:Medulla Oblongata / Q000166:cytology*; D009474:Neurons / Q000166:cytology