Figure 5.

Fewer MSN dendritic spines respond to photo-uncaging of MNI-NMDA after prolonged withdrawal from cocaine self-administration. A, Percent of spines responding to MNI-NMDA (50 μm) in cocaine rats (n = 122 spines; 10 cells; 4 rats) versus saline rats (n = 135 spines; 10 cells; 5 rats) [unpaired t test, t₍₂₅₅₎ = 2.290, p = 0.023]. B, The magnitude of Ca²⁺ responses [(F0/ΔF − 1) ×100] in “responding” spines did not differ between treatment groups [unpaired t test, t₍₁₁₄₎ = 0.113, p = 0.91]. C, Representative images showing Ca²⁺ influx in a dendritic segment from a cocaine animal in response to MNI-NMDA uncaging. *p < 0.05