Learning impairment caused by intra-CA1 microinjection of testosterone increases the number of astrocytes

Behav Brain Res. 2010 Mar 17;208(1):30-7. doi: 10.1016/j.bbr.2009.11.004. Epub 2009 Nov 10.

Abstract

The hippocampus is essentially involved in learning and memory, and is known to be a target for androgen actions. As neuron-astrocyte interactions play a crucial role during development and in the adult brain, it is thought that astrocytes support learning and memory through specific mechanisms. In this study, the effect of testosterone-induced impairment of acquisition and retrieval of long-term memory, on the number of astrocytes was studied. Adult male albino Wistar rats were bilaterally cannulated into the CA1 region and received 80 microg/0.5 microl of testosterone enanthate dissolved in DMSO as vehicle. In trained groups injection was done 30 min before training. Our results showed that pre-training administration of testosterone increased escape latency and the traveled distance, as compared to intact or DMSO administered (sham-operated) counterparts. Testosterone administration also increased the number of astrocytes in rats, compared to sham-operated and intact animals in both trained and non-trained groups. We have also found that spatial learning could increase the number of astrocytes in the hippocampus as a center of long-term learning and memory and recall. It is concluded that, testosterone-induced impairment in learning and memory, causes an increase in the number of astrocytes in the CA1 region of rat hippocampus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Androgens / pharmacology*
  • Animals
  • Astrocytes / pathology*
  • Behavior, Animal
  • Cell Count / methods
  • Hippocampus / drug effects*
  • Hippocampus / pathology
  • Learning Disabilities / chemically induced*
  • Learning Disabilities / pathology*
  • Male
  • Maze Learning / drug effects
  • Microinjections / methods
  • Neurons / pathology
  • Rats
  • Rats, Wistar
  • Reaction Time / drug effects
  • Testosterone / pharmacology*

Substances

  • Androgens
  • Testosterone