Multiple forms of somatostatin-like immunoreactivity are not influenced by cholinergic denervation of rat hippocampus.

Hippocampal choline acetyltransferase was reduced by 89% in rats two weeks after electrolytic lesion of the septum. The hippocampal concentrations of somatostatin (SOM)-14, SOM-28 and high-molecular-weight SOM were unaltered, suggesting that the activity of hippocampal SOM neurones is not influenced by cholinergic afferents. The relevance of this finding to Alzheimer-type dementia and Down's syndrome is discussed.