Extended Data Figure 5. Relationship between bidirectional and unidirectional connections and RF properties.
a, EPSP amplitude plotted against RF correlation from bidirectionally (red) and unidirectionally connected pairs (black). Replotted from Fig. 2g. b, EPSP amplitude for bi- or unidirectional connections. Bidirectional connections were stronger than unidirectional connections (median connection amplitude: 0.44 mV for bidirectional connections, n = 22; 0.16 mV for unidirectional connections, n = 50; P = 4.4 × 10−4, Wilcoxon rank-sum test). c, RF correlation for bidirectionally connected, unidirectionally connected and unconnected pairs. The RFs of bidirectionally connected pairs were more correlated than those of unidirectionally connected or unconnected pairs (median RF correlation: 0.3 for bidirectionally connected pairs, n = 11; 0.04 for unidirectionally connected pairs, n = 50; P = 0.002; and −0.02 for unconnected pairs, n = 191, P = 5.3 × 10−5), although unidirectionally connected pairs did not have higher RF correlations than unconnected pairs (P = 0.18, Wilcoxon rank-sum test). d, Mean EPSP amplitude versus RF correlation for all (yellow), unidirectionally (black) or bidirectionally (red) connected pairs. There was a positive relationship between RF correlation and connection amplitude for both unidirectional and bidirectional connections.