palæoˈthalamus Anat.
Also (chiefly U.S.) paleo-.
[mod.L., f. palæo-, paleo- b + thalamus.]
The phylogenetically older portion of the thalamus, usu. taken to include its anterior and medial parts.
| 1920 S. W. Ranson Anat. Nervous Syst. 391/1 (Index), Palæothalamus. See Thalamus, old. 1921 Tilney & Riley Form & Functions Cent. Nervous Syst. xxxi. 560 The primitive pars thalamica is known as the paleothalamus. 1958 L. Hausman Clin. Neuroanat. xxvii. 242 Phylogenetically, the hypothalamus, the epithalamus and part of the medial division of the dorsal thalamus constitute the old thalamus or paleothalamus. 1973 [see neothalamus]. |