Skip to main content
. Author manuscript; available in PMC: 2019 Feb 21.
Published in final edited form as: Neuroscience. 2017 Dec 15;372:306–315. doi: 10.1016/j.neuroscience.2017.12.003

Figure 3. Inhibiting mesolimbic TH+ neurons after nosepoke bout initiation decreases bout duration within an FR8 task. (a–e).

Figure 3

Inhibition of midbrain DA neurons upon each bout initiation decreases bout duration and total nosepokes in a 2-hr FR8 test session (n=10). (a) Time of in vivo DA neuron inhibition relative to behavioral events. A 15-sec laser pulse was triggered 0.01 seconds after mice completed a single nosepoke response for every such occurrence. (b–c) Decrease in mean responding (b) and probability of emitting additional nosepokes (c) during 15-sec laser on period compared to same period during a no inhibition session. ***p<0.001. Light green bar/line = inhibition session; black bar/line = control session. (d–e) Decrease in mean percentage of ratios completed (d) and mean total number of nosepokes ( e ) in inhibition sessions compared to no inhibition sessions. **p<0.01,***p<0.001. (f–k) Inhibition of midbrain DA neurons for 50% of initiated bouts decreases bout duration but not total nosepokes completed in a 2-hr FR8 test session (n=10). (f) Timing for in vivo DA neuron inhibition relative to behavioral events. A 15-sec laser pulse was triggered 0.01 seconds after mice completed a nosepoke response for 50% of bouts. (g–h) Decrease in mean responding (g) and probability of emitting additional nosepokes (h) during 15-sec inhibition period (Laser) compared to same time epochs (Sim Laser, simulated laser) during the same session. ***p<0.001. Light green bar/line = inhibition session; black bar/line = control session. (i) Mean total number of nosepokes was not changed after 50% in-bout DA neuron inhibition compared to a no inhibition session. (j) Mean percentage of ratios completed was decreased during the laser (Laser) on 50% of bouts with inhibition compared to the other 50% of bouts with no inhibition (Sim Laser, simulated laser) from the same session. ***p<0.001. (k) Mean number of bouts initiated was increased in the 50% in-bout DA neuron inhibition session compared to a separate no inhibition session. **p<0.01. All data reflect means +/− SEM.