Dopamine axons to dorsal striatum encode contralateral stimuli and actions

Abstract

Midbrain dopamine neurons play key roles in decision-making by regulating reward valuation and actions. These roles are thought to depend on dopamine neurons innervating striatum. In addition to actions and rewards, however, efficient decisions often involve consideration of uncertain sensory signals. The functions of striatal dopamine during sensory decisions remains unknown. We trained mice in a task that probed decisions based on sensory evidence and reward value, and recorded the activity of striatal dopamine axons. Dopamine axons in ventral striatum (VS) responded to bilateral stimuli and trial outcomes, encoding prediction errors that scaled with decision confidence and reward value. By contrast, dopamine axons in dorsal striatum (DS) responded to contralateral stimuli and contralateral actions. Thus, during sensory decisions, striatal dopamine signals are anatomically organized. VS dopamine resembles prediction errors suitable for reward maximization under sensory uncertainty whereas DS dopamine encodes specific combinations of stimuli and actions in a lateralized fashion.

Memory-specific encoding activities of the ventral tegmental area dopamine and GABA neurons

“…In both neuronal populations, more neurons showed opposite significant lap-trajectory preferences (red clusters) between delay and reward sections, as opposed to a small minority of neurons that elicited the same lap-trajectory preference (green clusters). Notably, in agreement with earlier studies reporting preferential contralateral responses of DA neurons ( Kim et al, 2015 ; Parker et al, 2016 ; Engelhard et al, 2019 ; Lee et al, 2019 ; Moss et al, 2020 ), the majority of memory-specific neurons exhibited a preference for the contralateral lap trajectory to that of the recording site (left hemisphere). Accordingly, seventeen (17) of the twenty-three (23) DA neurons with trajectory-specific activities in the delay period of the memory task, elicited a significant preference for the right trials and only five (5) of them for the left trials.…”

“…Notably, in agreement with earlier studies reporting preferential contralateral responses of DA neurons (Kim et al, 2015 ;Parker et al, 2016 ;Engelhard et al, 2019 ;Lee et al, 2019 ;Moss et al, 2020 ), the majority of memory-specific neurons exhibited a preference for the contralateral lap trajectory to that of the recording site (left hemisphere). Accordingly, seventeen ( 17 This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited.…”

Memory-specific encoding activities of the ventral tegmental area dopamine and GABA neurons

“…Notably, in agreement with earlier studies reporting preferential contralateral responses of DA neurons (Kim et al, 2015; Parker et al, 2016; Engelhard et al, 2019; Lee et al, 2019; Moss et al, 2020), the majority of memory-specific neurons exhibited a preference for the contralateral lap trajectory to that of the recording site (left hemisphere). Accordingly, seventeen (17) of the twenty-three (23) DA neurons with trajectory-specific activities in the delay period of the memory task, elicited a significant preference for the right trials and only five (5) of them for the left trials.…”

Multi-ensemble coordination between the direct and indirect striatal pathways actuates perceptual decisions

“…The asymmetry in the ensemble response patterns between dSPNs and iSPNs could be attributed to the differential synaptic strength in the cortical or thalamic input to different subtypes of SPNs, or could also be due to lateralized dopaminergic input 41 , and may depend on dopamine-dependent plasticity 42 . The mechanism for the regulation of synaptic input from the cortical and thalamic neurons encoding different sensory and motor variables during behavior and training is an important subject to be further investigated in the future.…”