Author: Lydia Ng @ Janelia NWB hackathon- User days 05/14/2019
- Tom Davidson ([email protected])
Tom described an experiment of freely behaving rat doing a W maze task. The experiment is typically on a small number of animals imaged over a long period of time. The rodent is plugged in (start extracellular recording using implanted probe) at the beginning of the day and will transition over different activities such as sleep in the sleep box, track 1, track 2, etc.
The rodent is freely behaving without constraints (eg they can stopped to groom or rest). The rodent initiates a “trial” by going to center port and doing a nose poke to receive a reward. Subsequent rewards depend on which order the rodent visit each ports. In an alternation task, the rodent needs will only be rewarded at port only after the have gone back to the center port, visited the other port, then the center port again before returning. Neural activity is recorded while the mouse is training and learning.
In additional to extracellular recordings, observations that are captured include video recording of the maze from which mouse spatial location is obtained. At a port, the rodent is rewarded with milk depending on the contingency. If the mouse does not traverse the track in the required way, reward will not be available and the rodent is put into a time out, or a tone is played or the lights is turned off. Other captured information include beam break, queue lights and the activation of the pump (to deliver milk).
Infrastructure needs to support unstructured exploration of the data. This includes ability to create “ad hoc” slicing of the timeseries into “trials” or repeats for analysis. In general, certain data should be use for the exploration and the other data reserved for validation to support generated hypothesis.
| Entity | Information |
|---|---|
| Species | Rat |
| Genetic Tools | n/a |
| Devices | implanted probes |
| Appartus | Linear or W track |
| Spatial coordinates & anatomy | First use Paxinos/Watson coordiates to target. Refinement through iteration over multiple specimens. Use the fact that LPF response and cell density profile to further refine probe location. Lesioning and histology is sometimes done to confirm location |
| Targted areas | hippocampus |
| Stimulus | N/A |
| Behavior | Complete lap of the track in prescribed order and receive milk reward at the ports |