Biology subjects

Gadagkar, V.

Publications and source records attributed to Gadagkar, V..

3 recordsLinked to original sources

bioRxiv2021

Dopamine Neurons Evaluate Natural Fluctuations in Performance Quality

Many motor skills are learned by comparing ongoing behavior to internal performance benchmarks. Dopamine neurons encode performance error in behavioral paradigms where error is externally induced, but it remains unknown if dopamine also signals the quality of natural performance fluctuations. Here we recorded dopamine neurons in singing birds and examined how spontaneous dopamine spiking activity correlated with natural fluctuations in ongoing song. Antidromically identified basal ganglia-projecting dopamine neurons correlated with recent, and not future, song variations, consistent with a role in evaluation, not production. Furthermore, dopamine spiking was suppressed following the production of outlying vocal variations, consistent with a role for active song maintenance. These data show for the first time that spontaneous dopamine spiking can evaluate natural behavioral fluctuations unperturbed by experimental events such as cues or rewards.

neuroscience↗

bioRxiv2020

Movement signaling in ventral pallidum and dopaminergic midbrain is gated by behavioral state in singing birds

Movement-related neuronal discharge in ventral tegmental area (VTA) and ventral pallidum (VP) is inconsistently observed across studies. One possibility is that some neurons are movement-related and others are not. Another possibility is that the precise behavioral conditions matter - that a single neuron can be movement related under certain behavioral states but not others. We recorded single VTA and VP neurons in birds transitioning between singing and non-singing states, while monitoring body movement with microdrive-mounted accelerometers. Many VP and VTA neurons exhibited body movement-locked activity exclusively when the bird was not singing. During singing, VP and VTA neurons could switch off their tuning to body movement and become instead precisely time-locked to specific song syllables. These changes in neuronal tuning occurred rapidly at state boundaries. Our findings show that movement-related activity in limbic circuits can be gated by behavioral context. Significance statementNeural signals in the limbic system have long been known to represent body movements as well as reward. Here we show that single neurons dramatically change their tuning to movements when a bird starts to sing.

neuroscience↗

bioRxiv2019

Dopamine neurons change their tuning according to courtship context in singing birds

How does courtship affect dopaminergic (DA) responses to reward and motor performance outcomes? We used electrophysiology and fiber photometry to record DA signals in two mesostriatal pathways as thirsty male songbirds sang alone and to females. When alone, water reward signals were observed globally but singing-related performance error signals were restricted to a song-specialized mesostriatal pathway. During courtship singing, DA responses to both water-predicting cues and song performance outcomes diminished, and DA signals in the song pathway were instead driven by female calls timed with the male song. Thus DA signals are dynamically gated and routed through distinct pathways as animals change their priorities in response to a courtship opportunity.

neuroscience↗