Interaction between midazolam-induced anterograde amnesia and memory enhancement by treatments given hours later in hippocampus, entorrhinal cortex or posterior parietal cortex

Behav Pharmacol. 1998 Mar;9(2):163-7.

Abstract

Rats were bilaterally implanted with indwelling cannulae in the CA1 region of the dorsal hippocampus, the entorrhinal cortex or the posterior parietal cortex. After recovery from surgery, they were trained in a one-trial step-down inhibitory avoidance task using a 0.3 mA footshock. The animals received i.p. 15 min before training either saline (1 ml/kg) or midazolam (1 mg/kg). Three hours after training they received, through the cannulae, infusions of saline, norepinephrine (0.3 microg/side), SKF38393 (7.5 microg/side), or 8-Br-cAMP (1.25 microg/side) into the brain regions mentioned. Animals were tested for retention 24 h after the training session. Midazolam produced anterograde amnesia, and the post-training treatments (with the exception of SKF38393 given into the entorrhinal cortex) caused retrograde memory facilitation. The amnestic effect of midazolam and the facilitatory effect of the treatments given into the brain cancelled each other out. Therefore, the mechanisms triggered by midazolam can interact with others in areas involved in memory processing several hours after their onset.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / pharmacology
  • 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / therapeutic use
  • 8-Bromo Cyclic Adenosine Monophosphate / pharmacology
  • 8-Bromo Cyclic Adenosine Monophosphate / therapeutic use
  • Amnesia / chemically induced
  • Amnesia / prevention & control*
  • Animals
  • Dopamine Agonists / pharmacology
  • Dopamine Agonists / therapeutic use
  • Drug Administration Routes
  • Drug Interactions
  • Entorhinal Cortex / drug effects*
  • Entorhinal Cortex / physiology
  • Hippocampus / drug effects*
  • Hippocampus / physiology
  • Male
  • Memory / drug effects*
  • Midazolam / pharmacology*
  • Parietal Lobe / drug effects*
  • Parietal Lobe / physiology
  • Prostheses and Implants
  • Rats
  • Rats, Wistar

Substances

  • Dopamine Agonists
  • 8-Bromo Cyclic Adenosine Monophosphate
  • 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine
  • Midazolam