Article Figures & Data
Figures
- Fig. 1.
Nucleus accumbens dopamine concentrations in rats self-administering intravenous doses (0.25 mg/kg per injection) of d-amphetamine. Dialysate samples were collected at 15 min intervals before the start of the self-administration session at time = 0 (baseline) and at 5 min intervals after the start of the session. Vertical dotted lines represent lever presses and associatedd-amphetamine infusions. DL numbers are rat identification numbers.
- Fig. 2.
Mean elevations over baseline in nucleus accumbens dopamine concentrations in rats receiving self-administered or experimenter-administered intravenous injections ofd-amphetamine. For each rat the mean dopamine concentration was calculated for the four samples before and after an injection occurred as well as for the sample during which the injection occurred. Only the results for dialysate samples collected after the first 60 min of the session were used. These data were then averaged within each group. The vertical dashed line represents the time of ad-amphetamine infusion.
- Fig. 3.
Nucleus accumbens dopamine concentrations in rats receiving experimenter-administered intravenous doses of d-amphetamine (0.25 mg/kg per injection).Top, These four rats (experienced–yoked) had a history of amphetamine self-administration. Bottom, These four rats (inexperienced–yoked) were naı̈ve to amphetamine and self-administration. Dialysate samples were collected at 10 min intervals before the start of the session at time = 0 (baseline) and at 5 min intervals after the start of the session. Vertical dotted lines represent the receipt of d-amphetamine infusions. A and DL numbers are rat identification numbers.
- Fig. 4.
Nucleus accumbens dopamine concentrations in rats lever pressing during a 3 hr extinction period (no drug available) and a 2 hr reinstatement period (drug available). The arrow in each graph represents the time at which a rat received a noncontingent (priming) injection ofd-amphetamine and drug was made available again. Thehorizontal dotted line represents the baseline DA concentration. Dialysate samples were collected at 10 min intervals during the extinction period and at 5 min intervals during the reinstatement period. DL numbers are rat identification numbers.
- Fig. 5.
Brain sections taken through the nucleus accumbens showing the locations of microdialysis probes (solid bars) for each of the rats tested here. Drawings are adapted from Pellegrino et al. (1979).
