Evidence for a ventral septal projection to the hippocampal formation of the rat

T. A. Milner, David G Amaral

Research output: Contribution to journalArticlepeer-review

93 Scopus citations

Abstract

In a series of experiments in which the known projections of the septal complex to the hippocampal formation have been transected, we have used both anterograde and retrograde tracing techniques in an attempt to demonstrate a ventral septo-hippocampal pathway. In cases where transections of the fimbria, dorsal fornix and supracallosal stria were complete, injections of the retrograde tracers wheat germ agglutinin-conjugated horseradish peroxidase or Fast blue, resulted in labeled cells in the ipsilateral septal complex, primarily in the nucleus of the diagonal band. The number of cells labeled in these experiments was approximately 5-10% of that seen in experiments in animals with intact dorsal pathways who had received similar injections. The presence of a ventral pathway was confirmed in anterograde labeling experiments in which injections of 3H-amino acids were made into the septal complex. The autoradiogfaphs demonstrated that the projection terminates most heavily in the entorhinal cortex and to a lesser extent in the ventral subicular complex; there may be an additional minor projection to the temporal half of the hippocampus and dentate gyrus. Finally, using double labeling procedures, we were able to demonstrate that at least a portion of the cell population that gives rise to the ventral pathway demonstrates choline acetyltransferase immunoreactivity and is presumably cholinergic.

Original languageEnglish (US)
Pages (from-to)579-585
Number of pages7
JournalExperimental Brain Research
Volume55
Issue number3
DOIs
StatePublished - Jul 1984
Externally publishedYes

Keywords

  • Cholinergic projections
  • Hippocampal afferents
  • Rat
  • Septo-Hippocampal projections

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint

Dive into the research topics of 'Evidence for a ventral septal projection to the hippocampal formation of the rat'. Together they form a unique fingerprint.

Cite this