[Qualitative and quantitative examinations of the nucleus motorius n. trigemini in ontogenetic series of male SPF cats and Tupaia belangeri].

The Nucl. motorius n. trigemini is qualitatively evaluated in Tupaia belangeri and SPF-cats with cyto-, myelo- and fibrilloarchitectonis methods. The criteria for demarcating the Nucl. motorius n. trigemini are also described. The quantitative evaluation was performed on ontogenetic series of 35 male Tupaia belangeri and 47 male SPF-cats. The growth of the fresh volume is described with the logistic growth function: y = (Formula: see text) The Nucl. motorius n. trigemini has bilaterally an ideal fresh volume of 0.80 mm3 in Tupaia belangeri and 3.43 mm3 in SPF-cats. In comparison with the whole brain, the Nucl. motorius n. trigemini shows a delayed development. In Tupaia belangeri, the half life of the fresh volume growth is 67.4 days of ontogenesis compared to 55.7 days of ontogenesis for the whole brain. In SPF-cats, the half life is 109.1 days of ontogenesis compared to 85.5 days of ontogenesis for the whole brain. The number of neurons in the right side of the Ncul. motorius n. trigemini in SPF-cats is described by a sum of exponential functions: y = P1 . eP2.t + P3 . eP4.t + P5. The nucleus reaches its ideal value of 2540 neurons at 85 days of ontogenesis. A perinatal spontaneous loss of neurons is observed in SPF-cats at a comparatively early period between the 39th and 47th day of ontogenesis. The loss is about 25% in comparison to the ideal value. The proof of over-shooting growth with spontaenous neuronal degeneration was demonstrated in SPF-cats. In this model, the exogenous influence of pathogenic origin could be excluded for this perinatal process.