New Approach in Behavioral Teratology—Experimental Study on FAS *

Abstract

ABSTRACT Fetal alcohol syndrome is known as an effect given by mothers. In connection with this, we so far observed rats from physical, biochemical, histological, and functional standpoints. Recently we observed synaptogenesis in brain together with behavior and learning ability of rats. Ethanol was given to mother rats during pregnancy and nursing periods, and learning ability of their offspring at 12 weeks of age was studied by the radial arm maze method. Also synaptogenesis in the hippocampus CA1 was observed at 2, 7, 14, 21, and 70 days of age by quantitative electron microscopy. The offspring were significantly deficient in learning ability tested with the maze compared with offspring of mother rats not exposed to ethanol. Densities of all synapses in the strata radiatum and lacunosum‐moleculare of CA1 in the hippocampus became significantly lower at every time of the observation. Both axo‐spinous and axo‐shaftic synapses significantly decreased. Thus we found that observations of learning ability agreed with observations of synaptogenesis in the hippocampus CA1 which has important association with memory. This fact suggests that both observations will be of great value in the research in behavioral teratology.