1. Neuroscience
Download icon

Thalamocortical and corticothalamic pathways differentially contribute to goal-directed behaviors in the rat

  1. Fabien Alcaraz
  2. Virginie Fresno
  3. Alain R Marchand
  4. Eric J Kremer
  5. Etienne Coutureau
  6. Mathieu Wolff  Is a corresponding author
  1. CNRS, INCIA, UMR 5287, France
  2. Université de Bordeaux, INCIA, UMR 5287, France
  3. Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, France
Research Article
Cite as: eLife 2018;7:e32517 doi: 10.7554/eLife.32517
9 figures and 1 additional file

Figures

Experimental design.

After an initial magazine training phase (MT), all rats underwent instrumental training consisting in either pushing a lever or a tilt (see methods) using successively fixed (FR) and random ratios (RR) schedules. To assess how the animals can use current goal value to guide choice, we performed a choice test immediately after selective outcome devaluation, under extinction conditions (both the lever and the tilt are now present in the chamber). After retraining, all rats underwent further instrumental training consisting in a selective degradation procedure (see methods). Another choice test was conducted after this phase, identical to that conducted following outcome devaluation. For both experiments, separate groups of rats were treated with either 1 mg/kg CNO or 1 ml/kg Saline 0.9% given 60 mm prior each behavioral session except during MT. To rule out any potential confounding effect of CNO injection alone, an additional control experiment is provided as an appendix. For each action, instrumental performance during the last RR10 session or the last RR10 retraining session was considered baseline for the devaluation test and the degradation phase, respectively.

https://doi.org/10.7554/eLife.32517.003
Dual-viral chemogenetic strategy to target TC (A) and CT pathways (D).

The CAV-2-Cre vector has a retrograde tropism. Maximal (grey) and minimal (dark) extent of DREADD expression in included rats at three rostrocaudal levels (expressed relative to Bregma, in mm) for CT (B) and TC (E) pathways. Representative examples of mCherry expression at thalamic (C) and cortical (F) levels. Insets in dashed green lines correspond to the higher magnification images provided on the right. CL: centrolateral thalamic nucleus, PC: paracentral thalamic nucleus, CM: centromedial thalamic nucleus, PV: paraventricular thalamic nucleus. A32 area corresponds to the prelimbic and most dorsal portion of the infralimbic areas in the seventh edition of the Paxinos and Watson atlas (Paxinos and Watson, 2014).

https://doi.org/10.7554/eLife.32517.004
Chemogenetic inhibition of TC pathways.

(A) Mean number of lever presses (±sem) during instrumental training. (B) Mean number of lever presses (±sem, relative to baseline) during the instrumental choice test conducted immediately after selective outcome devaluation under extinction conditions. (C) Consumption test. (D) Mean number of lever presses (±sem, relative to baseline) during the contingency degradation procedure. (E) Mean number of lever presses (±sem, relative to baseline) for the final choice test conducted under extinction conditions.

https://doi.org/10.7554/eLife.32517.005
Chemogenetic inhibition of corticothalamic pathways.

(A) Mean number of lever presses (±sem) during instrumental training. (B) Mean number of lever presses (±sem, relative to baseline) during the instrumental choice test conducted immediately after selective outcome devaluation under extinction conditions. (C) Consumption test. (D) Mean number of lever presses (±sem, relative to baseline) during the degradation procedure. (E) Mean number of lever presses (±sem, relative to baseline), for the final choice test conducted under extinction.

https://doi.org/10.7554/eLife.32517.006
Appendix 1—figure 1
Assessment of CNO without DREADD expression.

(A) Mean number of lever presses (±sem) during instrumental training. (B) Mean number of lever presses (±sem, relative to baseline) during the instrumental choice test conducted immediately after selective outcome devaluation under extinction conditions. (C) Consumption test.

https://doi.org/10.7554/eLife.32517.009
Appendix 1—figure 2
Assessment of CNO without DREADD expression.

Mean number of lever presses (±sem, relative to baseline) during the contingency degradation procedure.

https://doi.org/10.7554/eLife.32517.010
Appendix 1—figure 3
Assessment of CNO without DREADD expression.

Mean number of lever presses (±sem, relative to baseline) for the final choice test conducted under extinction conditions.

https://doi.org/10.7554/eLife.32517.011
Author response image 1
Experiment 1: inhibiting thalamocortical pathway.
https://doi.org/10.7554/eLife.32517.013
Author response image 2
Experiment 2: inhibiting corticothalamic pathway.
https://doi.org/10.7554/eLife.32517.014

Additional files

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Download citations (links to download the citations from this article in formats compatible with various reference manager tools)

Open citations (links to open the citations from this article in various online reference manager services)