Cells of origin of corticopontine and corticotectal fibers in the medial and lateral banks of the middle suprasylvian sulcus in the cat. An experimental study with the horseradish peroxidase method.
Cells of origin of corticopontine and corticotectal fibers in the medial and lateral banks of the cat middle suprasylvian sulcus (MSs area) were identified by means of the retrograde axonal transport of horseradish peroxidase. Somal diameters of labeled cells seen in the MSs area were measured after injection of the enzyme in the pons and the tectum. Diameters of corticopontine and corticotectal neurons are 12-35 microm (mean and SD: 18.9 + or - 3.2 microm) and 12-55 microm (mean and SD: 27.7 + or - 10.6 microm), respectively. These two kinds of neurons are both pyramidal in shape, located in layer V and the corticotectal neurons are, in general, larger and more polymorphic than the corticopontine cells. It thus appears that the two descending fibers originate from different, and independent sets of pyramidal neurons in layer V of the cortex.
Kawamura
K
K
Department of Anatomy, School of Medicine, Iwate Medical University, Morioka 020, Japan.
Konno
T
T
Chiba
M
M