Behavioral characterization of a transection of dorsal CA3 subcortical efferents: Comparison with scopolamine and physostigmine infusions into dorsal CA3

Michael R. Hunsaker, Jason L. Rogers, Raymond P. Kesner

Research output: Contribution to journalArticle

34 Scopus citations

Abstract

Cholinergic projections from the medial septum and diagonal band of Broca into the hippocampus have long been implicated in learning and memory. Projections from CA3 to neurons in the medial septum and the diagonal band of Broca have been anatomically characterized. The present experiments were designed to evaluate interactions between the dorsal CA3 subcortical efferents and the cholinergic efferents from the medial septum and diagonal band of Broca for spatial and nonspatial (visual object) novelty detection in the rat. In Experiment 1, physostigmine and scopolamine (both 0.4 μL at 30 μM) were infused into dorsal CA3 and animals were tested on a spatial and nonspatial (visual object) novelty detection paradigm. Scopolamine infusions into dorsal CA3 caused deficits for both spatial and nonspatial (visual object) novelty detection. Physostigmine infusions into dorsal CA3 enhanced both spatial and nonspatial (visual object) novelty detection. These data support models proposing that acetylcholine may control the dynamics for encoding, consolidation, and retrieval in the hippocampus. In Experiment 2, a selective transection of dorsal CA3 efferents in the fimbria resulted in deficits for spatial and nonspatial (visual object) novelty detection. These deficits were similar to the deficits caused by scopolamine infusions into dorsal CA3. These data demonstrate that dorsal CA3 and the medial septum/diagonal band of Broca interact, and that dorsal CA3 influences cholinergic inputs into the hippocampus to facilitate encoding.

Original languageEnglish (US)
Pages (from-to)127-136
Number of pages10
JournalNeurobiology of Learning and Memory
Volume88
Issue number1
DOIs
StatePublished - Jul 2007
Externally publishedYes

Keywords

  • Acetylcholine
  • CA3
  • Fimbria
  • Hippocampus
  • Learning and memory
  • Modulation
  • Novelty detection
  • Physostigmine
  • Scopolamine
  • Spatial learning

ASJC Scopus subject areas

  • Behavioral Neuroscience
  • Cognitive Neuroscience
  • Experimental and Cognitive Psychology

Fingerprint Dive into the research topics of 'Behavioral characterization of a transection of dorsal CA3 subcortical efferents: Comparison with scopolamine and physostigmine infusions into dorsal CA3'. Together they form a unique fingerprint.

  • Cite this