The use of horseradish peroxidase (HRP) in the stereological analysis of motor nuclei
Abstract
A quantitative analysis of the motor pools of the motor trigeminal nucleus in the rat was made. Localization of individual motor pools cannot be effected using standard histological techniques. Consequently, the muscles of mastication were separately injected with a 30% solution of HRP. The subsequent retrograde axonal transport of the enzyme, and its localization within the perikarya of efferent neurons permitted delineation of the motor pool subserving a particular muscle. In order to ensure that all cellular profiles in the pool were identifiable, the tissue sections were counterstained with Neutral Red. Mean diameters of neuronal somata were recorded, and frequency histograms constructed. All motor pools within the motor V nucleus were analysed; the results obtained from study of the mylohyoid motor pool are presented here.