Coherent theta activity in the medial and orbital frontal cortices encodes reward value
- Department of Neuroscience, American University, United States
Figures
Figure 1 with 1 supplement
Consummatory behavior tracked shifts in sucrose concentration and fluid volume.
(a) In the shifting values licking task, rats received access to one of two values of reward, with rewards alternating every 30 s. (b) Manipulation of reward value by changing either concentration …
Figure 1—figure supplement 1
Electrode localization.
Locations of all electrodes plotted in the horizontal plane. (a) Medial frontal cortex (MFC) (n = 10 rats; 160 electrodes) electrode arrays were localized around area 32 (A32D) and M2 (FrA) from 1 …
Figure 2
Coherent licking-related theta-band activity in the medial frontal (MFC) and orbital frontal (OFC) cortices.
(a) Depiction of rat performing the shifting values licking task (left) and placement of recording arrays in the MFC and lateral frontal cortex (right). (b) Traces of simultaneous local field …
Figure 3
Lick entrainment in the medial frontal (MFC) and orbital frontal (OFC) cortices is sensitive to reward value.
(a) Average lick-field coherence for local field potentials (LFPs) in MFC and OFC and licks for high and low concentration sucrose solutions and large and small fluid volumes. (b) Peak coherence in …
Figure 4 with 1 supplement
Lick-entrained neural activity in medial frontal cortex (MFC) and orbital frontal cortex (OFC) tracked shifts in sucrose concentration and fluid volume.
(a,e) Rats were implanted with a 2 × 8 electrode array in either MFC (a) or OFC (e); representative coronal sections are shown. (b,f) Event-related potentials during concentration and volume …
Figure 4—figure supplement 1
Electrophysiological measures used to assess local field potential (LFP) activity.
(a) Event-related potentials (ERPs) were recorded around licks (time 0) after LFP activity was filtered and z-scored. Peak-to-peak analysis was performed on the ERP centered around each lick with a …
Figure 5 with 1 supplement
Engagement in and the vigor of licking varied with reward expectation.
(a) Rats participated in a modification of the shifting values licking task, called the blocked-interleaved task, in which they received alternating access to high and low concentrations of liquid …
Figure 5—figure supplement 1
Transitions in licking behavior in the blocked-interleaved experiment.
Sessions were split into sequential 30 s windows and the various measures of licking behavior were plotted. An example from one of the rats is shown here. The plots in panel a depict high- and …
Figure 6
Lick-entrained neural activity varied with reward expectation.
(a,d) Event-related potentials (ERPs) for licks of both rewards in medial frontal cortex (MFC) (a) and orbital frontal cortex (OFC) (d) remain unchanged during the interleaved portion of the task. (b…
Figure 7
Neural activity in medial frontal cortex (MFC), but not orbital frontal cortex (OFC), varied with the lick rate (vigor) and not task engagement (total licks).
Post hoc contrasts of statistically significant effects revealed by two-way ANOVA. Direct comparison of behavioral measures (a – total licks; b – lick rate) with MFC inter-trial coherences (ITCs) (c)…
Figure 8
Consummatory behavior tracked relative differences in reward value.
(a) The three reward task is a variation of shifting values licking task but with a third reward introduced. In the first block of the task, rats experience the intermediate (8%) reward and low (4%) …
Figure 9
Neural activity in medial frontal cortex (MFC), but not orbital frontal cortex (OFC), tracked absolute differences in reward value.
(a,d) Event-related potentials (ERPs) for each block of the task from MFC (a) and OFC (d). (b,e) Inter-trial coherence (ITC) values in MFC (b) and OFC (e) showed strongest 4–8 Hz phase locking for …
Figure 10 with 2 supplements
Neural activity in medial frontal cortex (MFC), but not orbital frontal cortex (OFC), varied with effects of absolute reward value on lick rate (vigor) and task engagement (total licks).
(a,b) Behavioral measures replotted with significance bars for each combination reward. MFC inter-trial coherences (ITCs) (c) did not show the exact same pattern as lick rate, which is different …
Figure 10—figure supplement 1
Hypothesis for relative versus absolute encoding of reward value.
(a) If rewards are processed in an absolute manner, we expected to see a graded expression (in lick counts, lick rate, bout duration, or inter-trial coherence [ITC] values) of reward value where the …
Figure 10—figure supplement 2
Third block of testing in the three reward task.
In the third block of the three reward task, rats received access to 16% and 4% sucrose. In this block, licks for 16% sucrose can be compared against licks for both 4% and 8%, and likewise the licks …
Tables
Key resources table
| Reagent type (species) or resource | Designation | Source or reference | Identifiers | Additional information |
|---|---|---|---|---|
| Strain, strain background (Rattus norvegicus) | Sprague-Dawley, Long-Evans | Charles River, Envigo | NA | Rat (male) |
| Other | Precision Syringe Pump Controller | https://doi.org/10.1523/ENEURO.0240-19.2019 | SCR_021493 | |
| Software, algorithm | Med-PC | MedAssociates | SCR_012156 | |
| Software, algorithm | GNU Octave | https://www.gnu.org/software/octave/ | SCR_014398 | |
| Software, algorithm | R Project for Statistical Computing | https://www.r-project.org/ | SCR_001905 | |
| Software, algorithm | NeuroExplorer | https://www.neuroexplorer.com/ | SCR_001818 | |
| Software, algorithm | MatPlotLib | https://matplotlib.org/ | SCR_008624 | |
| Software, algorithm | IPython | https://ipython.org/ | SCR_001658 | |
| Software, algorithm | Jupyter | https://jupyter.org/ | SCR_018416 | |
| Software, algorithm | Seaborn | https://seaborn.pydata.org/ | SCR_018132 | |
| Software, algorithm | MATLAB | Mathworks | SCR_001622 | |
| Software, algorithm | EEGLab | https://sccn.ucsd.edu/eeglab/index.php | SCR_007292 |
