[Regio hypothalamica intermedia in Ovis aries L. III. Nucleus tuberomamillaris (author's transl)].

Nucl. tuberomamillaris was studied in 9, 6, and 2 month sheep and in new-born lambs of Merino breed. The gained results wer compared with some other mammals, mainly with the till now investigated farm animals. NTM was divided according NAV (1968) into pars supramamillaris and pars caudalis. The following findings were stated: 1. the rostral length of both NTM parts varies from the birth day til the 9th month of age, 2. till the 9th month of age the cytoplasma content in neurons is decreased and the Nissl substance content is increased. During the same time period the nerve cells, esp. in PC become till the 9th month clearly "tipped" often with the almost undefinitable form. 3. according the ageing the PSM cells begin to look like the PC neurons and these changes are mostly significant in the lateral connection to PC, 4. the glia cells and the blood capillaries number in PSM and in PC is changed only unsignificantly.