The effects of neonatal choline dietary supplementation on adult spatial and configural learning and memory in rats

Abstract

The facilitative effects of pre- and early postnatal choline chloride dietary supplementation on adult rat spatial and nonspatial learning and memory were examined using a delayed match-to-place and a transverse-patterning discrimination task. Animals were exposed to the choline supplementation both prenatally (through the diet of pregnant rats) and postnatally (subcutaneous injection) for 24 days. In the first experiment, 90-day-old rats were given pairs of trials in which they first found a hidden platform in a Morris water maze in a particular location (acquisition trials), and then were required to remember that position 10 min later (test trials). Those animals given neonatal choline pretreatment found the platform on test trials significantly faster than did animals in a saline-treated control group. All animals were subsequently tested in the same paradigm following atropine sulfate injections. The atropine eliminated the difference between experimental and control animals on test trials. In a second experiment, neonatally treated choline rats performed significantly better than controls in acquiring a visual transverse patterning discrimination task previously found to be sensitive to hippocampal and/or frontal damage. The present study extends the description of long-term functional enhancement produced by perinatal choline supplementation to include the ability to use and remember visual configural associations, working spatial memory, and to relate these effects to modifications in cholinergic basal forebrain systems.