Brain interleukin-1 is involved in spatial memory and passive avoidance conditioning

Neurobiol Learn Mem. 2002 Sep;78(2):379-89. doi: 10.1006/nlme.2002.4072.


Within the brain, the inflammatory cytokine interleukin-1 (IL-1) mediates illness-associated neural, neuroendocrine, and behavioral responses; however, its role in normal neurobehavioral processes is not clear. To examine the role of IL-1 signaling in memory, we infused Long-Evans rats intracerebroventricularly with IL-1beta (10 ng/rat), IL-1 receptor antagonist (IL-1ra, 100 microg/rat), or saline immediately following a learning task and tested memory functioning 1-8 days later. In the Morris water maze (MWM), IL-1ra caused memory impairment in the hippocampus-dependent, spatial version, whereas IL-1beta had no effect. Neither IL-1beta nor IL-1ra influenced the hippocampus-independent, nonspatial version of the MWM. In the passive avoidance response, which also depends on hippocampal functioning, IL-1ra caused memory impairment, and IL-1beta caused memory improvement. These results suggest that IL-1 signaling within the hippocampus plays a critical role in learning and memory processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Avoidance Learning / physiology*
  • Brain / metabolism*
  • Conditioning, Psychological / physiology*
  • Interleukin-1 / metabolism*
  • Male
  • Memory / physiology*
  • Rats
  • Rats, Long-Evans
  • Space Perception / physiology*
  • Time Factors


  • Interleukin-1