Journal of Neurophysiology, Vol 64, Issue 4 1223-1232, Copyright © 1990 by APS
Basal forebrain projections to somatosensory cortex in the cat
K. E. Barstad and M. F. Bear
Center for Neural Science, Brown University, Providence, Rhode Island 02912.
1. This investigation was designed to identify the source of cholinergic
basal forebrain projections to somatosensory cortex in the cat. 2.
Injections of horseradish peroxidase (HRP) into cortical areas 3a, 3b, and
1 after a 36 to 48-h survival period, labeled neurons in the basal
forebrain. The distribution of retrogradely labeled neurons was compared
with the distribution of cells labeled by choline acetyltransferase
immunocytochemistry. Most retrogradely labeled neurons in the basal
telencephalon were found on the border between the globus pallidus and
adjacent structures. Sometimes labeled neurons were also found in both
limbs of the diagonal band of Broca. 3. Excitotoxin lesions of these
regions of the basal telencephalon led to a profound depletion of
acetylcholinesterase-containing axons in primary somatosensory cortex. 4.
These data lay necessary groundwork for tests of the hypothesis that the
cholinergic projection modulates experience-dependent modifications in
adult cat somatosensory cortex.
