Article Figures & Data
Figures
- Figure 1.
Cocaine exposure increases locomotor activity, and PV intensity is correlated with WFA intensity. Data are the mean ± SEM. A, Timeline of experiment. B, Infrared photocell beam breaks the first 15 min after saline or cocaine injection (15 mg/kg, i.p.). A single cocaine exposure increased the locomotor response compared with the habituation (Hab) day. C, Repeated cocaine increased locomotor activity compared with their Hab day and with saline controls on day 4 (D4) and D5. D, Significant positive correlation between WFA staining intensity in WFA+/PV+ cells and cocaine-induced locomotor activity on day 2 when intensity was examined 2 h after 5 d of cocaine exposure (Fig. 1-1, available at https://doi.org/10.1523/ENEURO.0221-18.2018.f1-1, for all correlations). E, Representative photomicrograph of PV cells (red) with (yellow arrows) and without (blue arrows) WFA (green). WFA was also observed surrounding non-PV cells (white arrows). Scale bar, 100 µm. F, Significant positive correlation between WFA and PV intensity in rats 24 h after 5 d of saline (open circles) or cocaine (closed circles) exposure. For B and C: *p < 0.05, compared with saline group; +p < 0.05, compared with Hab group.
- Figure 2.
Cocaine exposure alters the intensity of WFA and PV in the prelimbic PFC. A, B, Intensity of WFA surrounding PV cells (WFA+/PV+ cells; A) and intensity of WFA surrounding all non-PV cells (WFA+/PV− cells; B) 2 or 24 h after acute (1 d) or repeated (5 d) saline (S) or cocaine (C) exposure in the prelimbic PFC. C, D, Intensity of PV cells that are surrounded by WFA (PV+/WFA+ cells; C) and intensity of PV+/WFA− cells (D) 2 or 24 h after acute or repeated saline or cocaine. N = 6–8 rats/group. *p < 0.05, compared with saline group.
- Figure 3.
Cocaine exposure alters intensity of WFA and PV in the infralimbic PFC. A, B, Intensity of WFA surrounding PV cells (WFA+/PV+ cells; A) and intensity of WFA surrounding all non-PV cells (WFA+/PV− cells; B) 2 or 24 h after acute (1 d) or repeated (5 d) saline (S) or cocaine (C) exposure in the infralimbic PFC. C, D, Intensity of PV cells that are surrounded by WFA (PV+/WFA+ cells; C) and intensity of PV+/WFA− cells PV cells (D) at 2 or 24 h after acute or repeated saline or cocaine exposure. N = 6–8 rats/group. *p < 0.05, compared to saline group.
- Figure 4.
Cocaine alters intensity of GABAergic (GAD65/67) puncta near PV neurons surrounded by PNNs in the prelimbic PFC. Cells were visualized with confocal microscopy and analyzed using Imaris segmentation tools. A, Representative PV neuron (red) surrounded by a PNN labeled with WFA (blue). B, The PV neuron is traced and a surface is created. C, The Mask Channel function was used to isolate GAD65/67 labeling to the area outside of the PV neuronal surface, and GAD65/67-labeled puncta (green arrowheads) were identified. D, GAD65/67-labeled puncta (green arrowheads) were then thresholded using the Imaris Spots tool. Spots that met the size criteria and were located adjacent to the PV neuron surface were included in the analysis (green arrows). E, F, VGluT1-labeled puncta (magenta arrowheads) were segmented separately using the same protocol (E), and VGluT1 spots meeting our size and location criteria were included in the analysis (magenta arrows; F). G–I, One day of cocaine exposure increases GAD 65/67 puncta (saline, N = 3, 45 cells; cocaine, N = 3, 49 cells; G), no change in VGluT1 puncta (H), and a trend toward an increase in the ratio of GAD65/67 to VGluT1 puncta (I). J, One day of cocaine exposure decreases PV cell volume. K–M, Five days of cocaine exposure increases GAD 65/67 puncta (saline, N = 4, 49 cells; cocaine, N = 6, 78 cells; K), yields no change in VGluT1 puncta (L), and increases the ratio of GAD65/67 to VGluT1 puncta (M). N, Five days of cocaine exposure does not alter PV cell volume. Data from bar graphs are the mean ± SEM. Scale bar, 3 µm. *p < 0.05 and #p < 0.1, compared with saline controls.
- Figure 5.
Intrinsic and synaptic properties of FSIs surrounded by PNNs exposed to cocaine in the prelimbic PFC. Data are the mean ± SEM. Fast-spiking interneuron properties 2 h following 1 or 5 d of saline or cocaine exposure. A, Recording locations in layer V of the prelimbic PFC. B, Action potentials recorded from FSIs surrounded by WFA. *p < 0.0001 comparing between saline and both cocaine groups; +p < 0.0001 comparing between saline and 1 d of cocaine exposure. C, Trace examples of recorded FSIs at 800 pA. Calibration: 50 ms, 50 mV. D, Trace example of first elicited action potential (AP). Dashed = saline exposure; gray = 1 d of cocaine exposure; black = 5 d of cocaine exposure. Calibration: 20 mV, 500 μs. E–K, Intrinsic properties were as follows: resting membrane potential (E), input resistance (F), AP threshold (G), rise time (H), AP amplitude (I), AP half-width (J), and AP afterhyperpolarization potential (K), comparing acute and repeated cocaine (C) to acute and repeated saline controls (S), respectively. L, Cumulative frequency plots of mEPSC amplitudes and interevent intervals. Trace examples are shown below. Calibration: 50 pA, 500 μs. M, Cumulative frequency plots of mIPSC amplitudes and interevent intervals. Trace examples are shown below. The number of cells/number of rats used is shown (E, L, M).
Tables
- Table 1.
Number of PV cells surrounded by WFA in prelimbic and infralimbic PFC after 1 or 5 d of saline or cocaine
Group Drug Region PV+/WFA+ 1 d 2 h Sal Prelimbic 88 ± 14 Coc 77 ± 8 Sal Infralimbic 61 ± 6 Coc 51 ± 7 5 d 2 h Sal Prelimbic 80 ± 12 Coc 70 ± 10 Sal Infralimbic 61 ± 8 Coc 66 ± 8 1 d 24 h Sal Prelimbic 89 ± 18 Coc 91 ± 21 Sal Infralimbic 45 ± 5 Coc 43 ± 11 5 d 24 h Sal Prelimbic 102 ± 16 Coc 108 ± 14 Sal Infralimbic 67 ± 8 Coc 49 ± 9 Coc, Cocaine; Sal, saline.
1 d 5 d Group Saline Cocaine Saline Cocaine Total GAG composition HS 17.9 ± 4.1% 19.3 ± 6.9% 18.4 ± 2.2% 17.2 ± 2.7% CS 54.3 ± 8.2 51.7 ± 11.6 52.8 ± 4.1 56.8 ± 4.4 HA 27.8 ± 10.6 29.0 ± 13.6 28.8 ± 6.2 26.0 ± 6.9 HS composition TriS 2.3 ± 1.2% 2.2 ± 1.6% 1.6 ± 0.4% 1.8 ± 0.2% NS6S 4.4 ± 1.3% 3.9 ± 1.8 3.9 ± 0.7 4.2 ± 0.6 NS2S 11.9 ± 3.5% 10.8 ± 4.1 8.7 ± 1.2 10.5 ± 0.8 NS 17.8 ± 2.9 16.7 ± 4.8 17.7 ± 1.3 18.2 ± 1.1 2S6S 0.1 ± 0.1 0.2 ± 0.1 0.1 ± 0.1 0.1 ± 0.1 6S 2.7 ± 1.2 2.6 ± 1.3 2.8 ± 0.5 3.0 ± 0.3 2S 0.5 ± 0.1 0.3 ± 0.2 0.5 ± 0.1 0.4 ± 0.1 0S 60.4 ± 8.9 63.2 ± 12.4 64.6 ± 3.6 61.7 ± 2.7 CS composition 2S4S 0.2 ± 0.1% 0.2 ± 0.1% 0.2 ± 0.1% 0.3 ± 0.1% 2S6S 1.1 ± 0.5 1.0 ± 0.5 0.8 ± 0.3 1.0 ± 0.3 4S6S 1.1 ± 0.2 1.1 ± 0.3 0.9 ± 0.1 1.0 ± 0.1 4S 89.8 ± 3.9 89.5 ± 3.4 90.3 ± 1.5 89.1 ± 2.0 6S 2.4 ± 0.9 1.9 ± 0.8 2.2 ± 0.5 2.7 ± 0.9 2S 0.2 ± 0.1 0.1 ± 0.1 0.2 ± 0.1 0.1 ± 0.1 0S 5.2 ± 2.5 6.1 ± 3.7 5.3 ± 1.5 5.8 ± 0.9
Figure 1-1
Table showing significant correlations between cocaine-induced locomotor activity and WFA or PV intensity in single- and double-labeled cells in the prelimbic and infralimbic PFC. Download Figure 1-1, DOC file.
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