Article Figures & Data
Figures
- Figure 1.
Cocaine-CPP is retained following SA and PA from cocaine experience. A, Timeline of experiments with labels for each experimental group. B, Place preference apparatus diagram with details for each stage of the cocaine-induced place conditioning procedure. C, Time spent in the black and white compartments during the preconditioning (PC) test confirms the unbiased construction of the testing apparatus. D, Preference ratio [(time in cocaine paired compartment/time spent in both compartments) × 100]. Saline-treated (black border) rats and cocaine-conditioned (gray border) rats tested 24 h after the last day of conditioning, after 8 d of abstinence [SA(+)] and after 30 d of abstinence [PA(+)]; *p = 0.0436, **p = 0.0002, ***p < 0.0001 indicate significantly above 50%.
- Figure 2.
Cocaine-associated context experience-dependent alterations in sEPSC properties in deep layer 5/6 pyramidal neurons of PL -and IL-mPFC. A, B, Comparison of sEPSC amplitude and frequency (mean ± SEM pA and Hz, respectively) from PL-mPFC versus IL-mPFC deep layer 5/6 pyramidal neurons in saline-treated control rats. C, Representative traces of sEPSC recordings from PL-mPFC pyramidal neurons for each experimental group with a diagram for recording location on brain slice. D, E, Comparison of sEPSC amplitude and frequency cumulative probability distributions from PL-mPFC pyramidal neurons for each experimental group. Insets show average data for sEPSC amplitude and frequency (mean ± SEM pA and Hz, respectively). F, Representative traces of sEPSC recordings from IL-mPFC pyramidal neurons for each experimental group with diagram for recording location on brain slice. G, H, Comparison of sEPSC amplitude and frequency cumulative probability distributions from PL-mPFC pyramidal neurons for each experimental group. Insets show average data for sEPSC amplitude and frequency (mean ± SEM pA and Hz, respectively). Statistics on bar graphs represent adjusted p values calculated from multiple t tests against saline control measurements corrected for multiple comparisons (Bonferroni-Dunn method). Cumulative probability distributions were tested individually against saline control distributions for each sEPSC measurement; *p < 0.05, **p < 0.005, ***p < 0.001, ****p < 0.0005. Numbers represent cells/rats. Scale bars: 100 ms (horizontal), 10 pA (vertical).
- Figure 3.
Cocaine-associated context experience-dependent alterations in the kinetics of sEPSCs in deep layer 5/6 pyramidal neurons of PL- and IL-mPFC. A, Average traces from single events in representative sEPSC recordings from PL-mPFC pyramidal neurons for each experimental group with diagram for recording location on brain slice. B, F, Average rise time from all events detected in sEPSC recordings for PL- and IL-mPFC pyramidal neurons respectively (mean ± SEM ms). C, G, Average decay time from all events detected in sEPSC recordings for PL- and IL-mPFC pyramidal neurons respectively (mean ± SEM ms). D, H, Average area under the curve from all events detected in sEPSC recordings for PL- and IL-mPFC pyramidal neurons respectively (mean ± SEM pA/ms). E, Average traces from single events in representative sEPSC recordings from PL-mPFC pyramidal neurons for each experimental group with diagram for recording location on brain slice. Statistics on bar graphs represent adjusted p values calculated from multiple t tests against saline control measurements corrected for multiple comparisons (Bonferroni-Dunn method); p < 0.05. Numbers represent cells/rats. Scale bars: 10 ms (horizontal), 10 pA (vertical).
- Figure 4.
Cocaine-associated context experience-dependent alterations in the RI in deep layer 5/6 pyramidal neurons of PL and IL-mPFC. A, B, Representative traces from single evoked EPSC recordings from PL- and IL-mPFC pyramidal neurons, respectively, at +40 mV (outward) and -70 mV (inward) for each experimental group with diagram for recording location on brain slice. B, D, Average RI values calculated as evoked EPSC amplitude at -70 mV over +40 mV membrane potentials for PL- and IL-mPFC pyramidal neurons respectively. Statistics on bar graphs represent adjusted p values calculated from multiple t tests against saline control measurements corrected for multiple comparisons (Bonferroni-Dunn method); p < 0.05. Numbers represent cells/rats. Scale bars: 100 ms (horizontal), 10 pA (vertical).
- Figure 5.
Summary diagram. Targeted effects of cocaine-CPP on PL- versus IL-mPFC deep layer 5/6 pyramidal neurons after SA or PA. A, Basal PL/IL difference in sEPSC frequency in cocaine naïve control rats: higher frequency of sEPSC in PL- neurons suggest more glutamate inputs to PL- versus IL-mPFC neurons, while no difference in the amplitude of sEPSC suggest no difference in postsynaptic receptor levels. B, SA from cocaine-CPP (left); SA(-): decreases sEPSC amplitude in PL- and IL –mPFC neurons implying a decrease in postsynaptic receptor levels. SA also produces a decrease in sEPSC amplitude and a decrease in the area under the curve of the average sEPSC. Reexposure to the conditioning context after SA (right); SA(+): reversal of changes to PL- and IL-mPFC neurons sEPSC amplitude to control levels. C, PA from cocaine-CPP(left); PA(-): PL- neurons show an increase in AMPA receptor RI suggesting higher levels of GluA2-lacking AMPARs. Reexposure to the conditioning context after PA(right); PA(+): changes in average sEPSC kinetics are reversed in PL- and IL-mPFC neurons. Increase in AMPAR RI in PL-mPFC neurons is reversed to control levels.
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