Not only did the axo-shaft synapses exhibit a robust increase of GluR1 immunoreactivity among the paired group, but they also exhibited a significant decrease in GluR1 immunoreactivity among the unpaired group (Fig. 7). Although the decline in the proportion of axo-shaft synapses labeled among the unpaired group did not reach statistical significance (P = 0.09; Fig. 7A), the PEG counts per synapse did (Fig. 7B). Specifically, PEG counts at the synaptic junction decreased by 84%, relative to the that of the naïves, and this difference was significant (P < 0.005). This decrease at the axo-shaft synapses contrast sharply with the pattern observed at spines of the unpaired group, namely, the absence of change of PEG counts at axo-spinous synapses and a slight trend toward an increase in the proportion of spines immunolabeled at the synaptic junction, relative to that of the naïves (P = 0.10; Fig. 6C).
