Apr 02, 2025
Behavioral tasks-Falasconi & Kanodia et al 2025
- Antonio Falasconi1,2,3,
- Harsh Kanodia1,2,3,
- Silvia Arber1,2,3
- 1Biozentrum, University of Basel;
- 2Friedrich Miescher Institute for Biomedical Research;
- 3Aligning Science Across Parkinson’s (ASAP)
Protocol Citation: Antonio Falasconi, Harsh Kanodia, Silvia Arber 2025. Behavioral tasks-Falasconi & Kanodia et al 2025. protocols.io https://dx.doi.org/10.17504/protocols.io.e6nvwby22vmk/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: February 19, 2025
Last Modified: April 02, 2025
Protocol Integer ID: 121886
Keywords: ASAPCRN
Funders Acknowledgements:
Aligning Science Across Parkinson’s
Grant ID: ASAP-020551
European Union’s Horizon 2020 research and innovation programme
Grant ID: InterAct, grant agreement No 101018151
Swiss National Science Foundation
Grant ID: N/A
Abstract
Protocol for freely moving pellet or water reaching, lever pressing and open field behavioral assays from Falasconi & Kanodia et al 2025.
Guidelines
Food restricted animals: The body weight of mice and food consumption is monitored daily to stay around 85% of original body weight and to not drop below 80% of the baseline weight.
Water restricted animals: The body weight of mice and water consumption was monitored daily to stay around 85% of original body weight and to not drop below 80% of baseline weight.
Materials
Reaching Task & Lever press Chamber
The chamber was built from clear Plexiglas (~15x5cm). One vertical slit was located on the front wall of the box.
Open Field
The open field box was 30x30 cm.
Safety warnings
Wear appropriate PPE as required by your institution.
Ethics statement
Prior ethics approval should be obtained before performing these experiments. Approval was obtained from the Cantonal Veterinary Office Basel-Stadt and performed in compliance with the Swiss Veterinary Law guidelines.
Before start
All mice require to be food or water restricted prior to beginning this protocol.
Acclimation and Habituation
Acclimation and Habituation
Prior to the first experimental day, mice will be gently handled and habituated to the experimental context (chamber). Animals will be subjected to several of the mentioned tasks according to the brain area under study and the results obtained.
Reaching task (Food Pellet or Water Droplet)
Reaching task (Food Pellet or Water Droplet)
After initial habituation, the mouse is allowed to reach for multiple rewards (pellets or water droplets) presented to them outside the box to determine the preferred limb.
Note-mice were encouraged to use the forelimb for reaching trials by placing rewards at a consistent position outside the slit and were trained for 5-10 days.
For experimental days: place mouse in training chamber and begin recording from the cameras and electrophysiology equipment.
Allow mouse to reach for individual rewards (small food pellets or 5-10 micro-liter water drops).
This task will continue as long as the mouse is motivated to reach for a reward.
After completion of the task, mice receive one standard size food pellet (if food restricted) or 1ml of water (if water restricted) in order to maintain body weight around 85% of original weight.
Lever Pressing Task
Lever Pressing Task
After initial habituation, the mouse is allowed to reach for food or water presented to them outside the box to determine the preferred limb.
A mouse is trained that the visual signal of a blue LED presenteed for 100 ms then the mouse has 1.5 seconds to respond/press lever. Each inter trial interval is 2-5 seconds. If the mouse presses the lever they are rewarded.
If a mouse does not press the lever within the 1.5 second window, no reward is given.
A mouse is trained for 2-4 weeks in total with 1-day break minimally every 14 days.
During experimental sessions: Record the behavior session with cameras and any electrophysiology equipment for brain regions of interest.
The mouse will receive the visual cue to press the lever and receive a reward for lever pressing with the same criteria as in training.
After completion of the task, mice receive one standard size food pellet (if food restricted) or 1ml of water (if water restricted) in order to maintain body weight around 85% of original weight.
A mouse will be assessed in this task for a maximum of 14 consecutive days.
Optogenetic Experiments in Lever Pressing Task
Optogenetic Experiments in Lever Pressing Task
Optogenetic stimulation are performed using a PlexBright Optogenetic Stimulation System (Plexon Inc.) in combination with lasers (Cobolt 06-MLD, 473nm; Cobolt 06-DPL, 532 nm).
Measure laser intensity at the beginning of every session with an optical power meter (Thorlabs Inc.) on the tip of an optic fiber of the same characteristics as the one implanted to ensure consistent stimulation power.
Deliver light via a patch cord and rotary joint (Doric Lenses) connected to the animal’s optic fiber (Doric Lenses C60 or FLT).
Optogenetic stimulation was provided at cue offset (100ms from visual cue presentation) on 40-50% of randomly selected trials using the same criteria for lever pressing rewards as above.
Optogenetic Experiments in Open Field
Optogenetic Experiments in Open Field
Optogenetic stimulation are performed using a PlexBright Optogenetic Stimulation System (Plexon Inc.) in combination with lasers (Cobolt 06-MLD, 473nm; Cobolt 06-DPL, 532 nm).
Measure laser intensity at the beginning of every session with an optical power meter (Thorlabs Inc.) on the tip of an optic fiber of the same characteristics as the one implanted to ensure consistent stimulation power.
Deliver light via a patch cord and rotary joint (Doric Lenses) connected to the animal’s optic fiber (Doric Lenses C60 or FLT).
Place mouse in the open field box and allow to freely move for ~30 minutes while recording motor activity with cameras.
Deliver light when the mouse crossed a locomotor speed (centroid speed) threshold of 10cm/s for 150ms during the 30 minute session.
Protocol references
Esposito, M., Capelli, P. & Arber, S. Brainstem nucleus MdV mediates skilled forelimb motor tasks. Nature 508, 351–356 (2014). https://doi.org/10.1038/nature13023
Galiñanes, Gregorio Luis, et al. "Directional Reaching for Water as a Cortex-Dependent Behavioral Framework for Mice." Cell Reports, vol. 22, no. 2767-2783, 6 Mar. 2018, doi:10.1016/j.celrep.2018.02.042
Jin X, Costa RM. Start/stop signals emerge in nigrostriatal circuits during sequence learning. Nature. 2010 Jul 22;466(7305):457-62. doi: 10.1038/nature09263. PMID: 20651684; PMCID: PMC3477867.