The striatum plays a central role in motor control, yet how it dynamically represents variables such as locomotion speed, particularly across varying behavioral contexts, remains incompletely understood. Here, we investigated striatal encoding of locomotion speed in rats performing an automated T-maze task. We found that the activity of most (78%) analyzed striatal neurons- referred to as speed cells-was robustly correlated, either positively or negatively, with locomotion speed. This population included both putative medium spiny neurons (MSNs; 74%) and fast-spiking interneurons (FSIs; 82%). Speed-related activity was remarkably stable, showing no significant influence of elapsed time, cue type, spatial choice, or trial outcome. Additionally, positively correlated MSNs tended to precede speed changes, while positively correlated FSI activity typically followed, as did negatively correlated neurons for both types. This suggests distinct roles for different striatal cells in movement modulation. Speed cells exhibited strong modulation at movement onset and offset, yet also maintained correlations with speed throughout locomotion bouts. Finally, the firing rates of speed cells reliably predicted locomotion speed, outperforming non-speed cells and chance levels; decoding accuracy further improved when data from multiple neurons were combined, consistent with a population code. Together, these results demonstrate a robust, context-independent representation of locomotion speed in the rat striatum, driven by diverse cell types, and extends previous findings to a task with greater cognitive demands.

The generation and learning of movements involves interactions among specific neuronal populations within and across brain regions. Important among these regions, for movement among other functions, are the basal ganglia, a set of evolutionarily conserved interconnected deep-brain nuclei. This is strikingly illustrated by how their pathological dysfunction in Parkinson's disease deeply impacts the ability to move. The basal ganglia control the production of different movements through dedicated circuits. These span multiple brain nuclei with complex but highly organized entry and exit routes, from the striatum, the classical input nucleus, to the substantia nigra pars reticulata (SNr), one main output nucleus. Decades of research have focused on understanding the signals that are processed through basal ganglia circuitry and how they contribute to the control of movement. In this primer, we focus on direct interactions between basal ganglia and the brainstem, through which specific populations of basal ganglia output neurons communicate with select brainstem motor centers to influence descending circuits for action. Breakthroughs in understanding brainstem circuits for action execution have made it possible to map the organization and function of the interface between basal ganglia and brainstem. This combined work has led to deep insights into how basal ganglia regulate movement with great granularity.

Many prosocial and antisocial behaviors simultaneously impact both ourselves and others, requiring us to learn from their joint outcomes to guide future choices. However, the neurocomputational processes supporting such social learning remain unclear. Across three pre-registered studies, participants learned how choices affected both themselves and others. Computational modeling tested whether people simulate how other people value their choices or integrate self- and other-relevant information to guide choices. An integrated value framework, rather than simulation, characterizes multi-outcome social learning. People update the expected value of choices using different types of prediction errors related to the target (e.g., self, other) and valence (e.g., positive, negative). This asymmetric value update is represented in brain regions that include ventral striatum, subgenual and pregenual anterior cingulate, insula, and amygdala. These results demonstrate that distinct encoding of self- and other-relevant information guides future social behaviors across mutually beneficial, mutually costly, altruistic, and instrumentally harmful scenarios.

Basal Ganglia Advances is a collection highlighting research on the structure, function, and disorders of the basal ganglia. It features studies spanning neuroscience, clinical insights, and computational models, serving as a hub for advances in movement, cognition, and behavior.

Recent advances in the field of Voltage Imaging, with a special focus on new constructs and novel implementations.

Work related to place tuning, spatial navigation, orientation and direction. Mainly includes articles on connectivity in the hippocampus, retrosplenial cortex, and related areas.

Many prosocial and antisocial behaviors simultaneously impact both ourselves and others, requiring us to learn from their joint outcomes to guide future choices. However, the neurocomputational processes supporting such social learning remain unclear. Across three pre-registered studies, participants learned how choices affected both themselves and others. Computational modeling tested whether people simulate how other people value their choices or integrate self- and other-relevant information to guide choices. An integrated value framework, rather than simulation, characterizes multi-outcome social learning. People update the expected value of choices using different types of prediction errors related to the target (e.g., self, other) and valence (e.g., positive, negative). This asymmetric value update is represented in brain regions that include ventral striatum, subgenual and pregenual anterior cingulate, insula, and amygdala. These results demonstrate that distinct encoding of self- and other-relevant information guides future social behaviors across mutually beneficial, mutually costly, altruistic, and instrumentally harmful scenarios.

The striatal direct and indirect pathways constitute the core for basal ganglia function in action control. Although both striatal D1- and D2-spiny projection neurons (SPNs) receive excitatory inputs from the cerebral cortex, whether or not they share inputs from the same cortical neurons, and how pathway-specific corticostriatal projections control behavior remain largely unknown. Here using a G-deleted rabies system in mice, we found that more than two-thirds of excitatory inputs to D2-SPNs also target D1-SPNs, while only one-third do so vice versa. Optogenetic stimulation of striatal D1- vs. D2-SPN-projecting cortical neurons differently regulate locomotion, reinforcement learning, and sequence behavior, implying the functional dichotomy of pathway-specific corticostriatal subcircuits. These results reveal the partially segregated yet asymmetrically overlapping cortical projections on striatal D1- vs. D2-SPNs, and that the pathway-specific corticostriatal subcircuits distinctly control behavior. It has important implications in a wide range of neurological and psychiatric diseases affecting cortico-basal ganglia circuitry.

Synchronous neuronal ensembles play a pivotal role in the consolidation of long-term memory in the hippocampus. However, their organization during the acquisition of spatial memory remains less clear. In this study, we used neuronal population voltage imaging to investigate the synchronization patterns of mice CA1 pyramidal neuronal ensembles during the exploration of a new environment, a critical phase for spatial memory acquisition. We found synchronous ensembles comprising approximately 40% of CA1 pyramidal neurons, firing simultaneously in brief windows (~25ms) during immobility and locomotion in novel exploration. Notably, these synchronous ensembles were not associated with contralateral ripple oscillations but were instead phase-locked to theta waves recorded in the contralateral CA1 region. Moreover, the subthreshold membrane potentials of neurons exhibited coherent intracellular theta oscillations with a depolarizing peak at the moment of synchrony. Among newly formed place cells, pairs with more robust synchronization during locomotion displayed more distinct place-specific activities. These findings underscore the role of synchronous ensembles in coordinating place cells of different place fields.