Parallel thalamic activation of the first and second somatosensory areas in prosimian primates and tree shrews
Article first published online: 9 OCT 2004
Copyright © 1991 Wiley-Liss, Inc.
Journal of Comparative Neurology
Volume 311, Issue 2, pages 289–299, 8 September 1991
How to Cite
Garraghty, P. E., Florence, S. L., Tenhula, W. N. and Kaas, J. H. (1991), Parallel thalamic activation of the first and second somatosensory areas in prosimian primates and tree shrews. J. Comp. Neurol., 311: 289–299. doi: 10.1002/cne.903110209
- Issue published online: 9 OCT 2004
- Article first published online: 9 OCT 2004
- Manuscript Accepted: 29 MAY 1991
- somatosensory cortex;
- thalamocortical projections;
In Tupaia belangeri and Galago senegalensis, microelectrode recordings immediately after ablation of the representation of the forelimb in the midportion of the first somatosensory area, S-I, revealed that all parts of the second somatosensory area, S-II, remained highly responsive to cutaneous stimuli. In this way, prosimian primates, close relatives of simian primates, and tree shrews differ markedly from monkeys in which S-II is deactivated by comparable ablations, and resemble such mammals as cats and rabbits in which S-II also remains highly responsive following ablations in S-I. Thus, it appears that the generalized mammalian condition is that S-I and S-II are independently activated via parallel thalamocortical pathways. A dependence of S-II on serial connections from the thalamus to the S-I region and then to S-II apparently evolved with the advent of anthropoid primates, and may be present only in monkeys and perhaps other higher primates.