Role of fear in mediating shuttle escape learning deficit produced by inescapable shock

J Exp Psychol Anim Behav Process. 1990 Apr;16(2):137-49.


The relation between the shuttlebox escape deficit produced by prior inescapable shock (IS) and fear during shuttlebox testing as assessed by freezing was investigated in rats. IS rats learned to escape poorly and were more fearful than either escapably shocked subjects or controls, both before and after receiving shock in the shuttlebox. However, fear and poor escape performance did not covary with the manipulation of variables designed to modulate the amount of fear and the occurrence of the escape deficit. A 72-hr interval between IS and testing eliminated the escape deficit but did not reduce preshock freezing. Diazepam before testing reduced both preshock and postshock fear in the shuttlebox but had no effect on the escape deficit. Naltrexone had no effect on fear but eliminated the escape deficit. This independence of outcomes suggests that the shuttlebox escape deficit is not caused by high levels of fear in IS subjects.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Arousal* / drug effects
  • Conditioning, Classical* / drug effects
  • Cues
  • Diazepam / pharmacology
  • Electroshock
  • Escape Reaction* / drug effects
  • Fear* / drug effects
  • Helplessness, Learned
  • Male
  • Mental Recall / drug effects
  • Motor Activity / drug effects
  • Naltrexone / pharmacology
  • Rats
  • Rats, Inbred Strains
  • Transfer, Psychology


  • Naltrexone
  • Diazepam