Cruz, B. F. P. | bioRxiv Science

bioRxiv2022

GoFish: A low-cost, open-source platform for closed-loop behavioural experiments on fish

Fish are the most species-rich vertebrate group, displaying vast ecological, anatomical and behavioural diversity, and therefore are of major interest for the study of behaviour and its evolution. Despite this, with respect to other vertebrates, fish are relatively underrepresented in behavioural research. This is partly due to the difficulty of implementing stimuli, manipulanda, and data recording underwater, meaning that this is frequently done with gates to control subjects, physical displays as stimuli, and visual annotation of videos to record data. To overcome these restrictions we developed GoFish, a fully-automated platform for behavioural experiments. GoFish includes real-time video tracking of subjects, presentation of stimuli in a computer screen, an automatic feeder device, and closed-loop control of task contingencies and data acquisition. The design and software components of the platform are freely available, while the hardware is widely available and relatively inexpensive. The control software, Bonsai, is user-friendly and supported by a growing community of users. As an illustration and test of its use, we present the results of 2 experiments on discrimination learning, reversal, and choice in goldfish (Carassius auratus). GoFish enables the relatively easy implementation of high-throughput tasks and the acquisition of rich behavioural data. Our platform has the potential to become a widely used tool that facilitates complex behavioural experiments in aquatic species.

animal behavior and cognition↗

bioRxiv2020

Manipulation of striatal population dynamics using temperature warps judgment of time

The basal ganglia (BG) are thought to contribute to decision-making and motor control by influencing action selection based on consequences. These functions are critically dependent on timing information that can be extracted from the evolving state of neural populations in the striatum, the major input area of the BG. However, it is debated whether striatal activity underlies latent, dynamic decision processes or kinematics of overt movement. Here, we measured the impact of temperature on striatal population activity and the behavior of rats and compared the observed effects to neural activity and behavior collected in multiple versions of a temporal categorization task. Cooler temperatures caused dilation, and warmer temperatures contraction, of both neural activity and patterns of judgment in time, mimicking endogenous decision-related variability in striatal activity. However, temperature did not similarly affect movement kinematics. These data provide compelling evidence that the time course of evolving striatal population activity dictates the speed of a latent process that is used to guide choices, but not moment by moment kinematics. More broadly, they establish temporal scaling of population activity as a likely cause and not simply a correlate of timing behavior in the brain.

neuroscience↗