Biology subjects

Vendrell-Llopis, N.

Publications and source records attributed to Vendrell-Llopis, N..

3 recordsLinked to original sources

bioRxiv2023

Distinct neural representations during a brain-machine interface and manual reaching task in motor cortex, prefrontal cortex, and striatum

Although brain-machine interfaces (BMIs) are directly controlled by the modulation of a select local population of neurons, distributed networks consisting of cortical and subcortical areas have been implicated in learning and maintaining control. Previous work in rodent BMI has demonstrated the involvement of the striatum in BMI learning. However, the prefrontal cortex has been largely ignored when studying motor BMI control despite its role in action planning, action selection, and learning abstract tasks. Here, we compare local field potentials simultaneously recorded from the primary motor cortex (M1), dorsolateral prefrontal cortex (DLPFC), and the caudate nucleus of the striatum (Cd) while nonhuman primates perform a two-dimensional, self-initiated, center-out task under BMI control and manual control. Our results demonstrate the presence of distinct neural representations for BMI and manual control in M1, DLPFC, and Cd. We find that neural activity from DLPFC and M1 best distinguish between control types at the go cue and target acquisition, respectively. We also found effective connectivity from DLPFC[->]M1 throughout trials across both control types and Cd[->]M1 during BMI control. These results suggest distributed network activity between M1, DLPFC, and Cd during BMI control that is similar yet distinct from manual control.

neuroscience↗

bioRxiv2022

A neural model of proximity to reward

Throughout learning, refinement of cortical activity in cortex, a process termed "credit assignment", underlies the refinement of behavioral actions leading to reward. While previous research shows striatums role in linking behavior to reward, striatums role in linking the underlying behaviorally-relevant cortical activity to reward remains unclear. Leveraging a neuroprosthetic task while recording from the rat cortex and striatum, we demonstrate that the striatum encodes the dynamics of the proximity of cortical activity to reward. Such encoding was independent from external task feedback and emerged as cortical activity consolidated over learning, with dorsal and ventral striatum playing complementary yet distinct roles. Striatal activity thus constitutes a neural model of cortical progress towards reward, suggesting one mechanism by which the brain implements credit assignment to refine behavior.

neuroscience↗

bioRxiv2021

Diverse operant control of different motor cortex populations during learning

During motor learning, as well as during neuroprosthetic learning, animals learn to control motor cortex activity in order to generate behavior. Two different population of motor cortex neurons, intra-telencephalic (IT) and pyramidal tract (PT) neurons, convey the resulting cortical signals within and outside the telencephalon. Although a large amount of evidence demonstrates contrasting functional organization among both populations, it is unclear whether the brain can equally learn to control the activity of either class of motor cortex neurons. To answer this question, we used a Calcium imaging based brain-machine interface (CaBMI) and trained different groups of mice to modulate the activity of either IT or PT neurons in order to receive a reward. We found that animals learn to control PT neuron activity faster and better than IT neuron activity. Moreover, our findings show that the advantage of PT neurons is the result of characteristics inherent to this population as well as their local circuitry and cortical depth location. Taken together, our results suggest that motor cortex is optimized to control the activity of pyramidal track neurons, embedded deep in cortex, and relaying motor commands outside of the telencephalon.

neuroscience↗