In order to determine whether fear conditioning altered levels of receptors containing specific subunits of AMPARs, the mean number of PEG particles at synaptic and nonsynaptic sites was determined for each animal, and the mean values of each animal were compared across treatments. To avoid oversampling of data from any single animal’s tissue, the number of spines sampled from each animal was equalized to 164 for the GluR1 samples and 126 for the GluR2/3 samples. A one-way ANOVA and Fisher’s LSD post hoc comparisons were performed upon these data as well.
