Chronic intracerebroventricular exposure to beta-amyloid(1-40) impairs object recognition but does not affect spontaneous locomotor activity or sensorimotor gating in the rat

Exp Brain Res. 2001 Jan;136(1):93-100. doi: 10.1007/s002210000561.

Abstract

This study examined the cognitive effects of chronic in vivo exposure to beta-amyloid(1-40) via the intracerebroventricular route on two distinct paradigms. The first test evaluated a form of early attentional control referred to as sensorimotor gating in which an antecedent weak prepulse stimulus modulates the reactivity to a subsequent startle-eliciting stimulus. The second test utilized the spontaneous preference for a novel object over that of a familiar one in rats as a measure of object recognition memory. We found that beta-amyloid exposure leads to a severe deficit in the object memory test but spares sensorimotor gating. Moreover, unlike the water maze deficit induced by beta-amyloid (Nag et al., in preparation), the deficit on object recognition was resistant to amelioration by systemic physostigmine treatment at a dose of 0.06 mg/kg per day intraperitoneally. The present results add to previous reports that beta-amyloid exposure can lead to deficits on hippocampal lesion sensitive tasks, suggesting that dysfunction of the rhinal cortices in addition to that of the septohippocampal system is implicated in beta-amyloid-induced behavioral impairments. It therefore lends support to the hypothesis that beta-amyloid exposure can lead to severe impairment across multiple memory systems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation / methods
  • Amyloid beta-Peptides / pharmacology*
  • Animals
  • Cerebral Ventricles / drug effects
  • Cerebral Ventricles / physiology
  • Cholinesterase Inhibitors / pharmacology*
  • Entorhinal Cortex / drug effects
  • Entorhinal Cortex / physiology
  • Hippocampus / drug effects
  • Hippocampus / physiology
  • Male
  • Motor Activity / drug effects*
  • Motor Activity / physiology
  • Parathion / pharmacology*
  • Peptide Fragments / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Recognition, Psychology / drug effects*
  • Recognition, Psychology / physiology
  • Reflex, Startle / drug effects*
  • Reflex, Startle / physiology

Substances

  • Amyloid beta-Peptides
  • Cholinesterase Inhibitors
  • Peptide Fragments
  • amyloid beta-protein (1-40)
  • Parathion