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Rautio, I. V.

Publications and source records attributed to Rautio, I. V..

3 recordsLinked to original sources

Prefrontal cortex encodes behavior states decoupled from movement

Prefrontal cortex is often viewed as an extension of the motor system, but little is understood of how it relates to natural motor behavior. We therefore tracked the kinematics of freely moving rats performing minimally structured tasks and measured which aspects of behavior were read out in prefrontal neural populations. Naturalistic behaviors such as rearing or chasing a bait were each encoded by unique neural ensembles, but the behavioral representations were not anchored to posture or movement. Rather, the coding of kinematic features depended on their relevance to the animals current behavior or which task the animal performed. Behavior-specific ensembles often preceded and outlasted physical actions and, accordingly, prefrontal population activity evolved at slower timescales than in motor cortex. These findings argue that prefrontal coding of behavior is not locked to motor output, and may instead reflect motivations to perform certain actions rather than the actions themselves. HighlightsO_LIPrefrontal neural ensembles uniquely encode different naturalistic actions C_LIO_LIBehavioral tuning is not explained by movement kinematics C_LIO_LIPopulation activity in prefrontal cortex evolves slower than in M1 C_LIO_LISingle-cell coding of behavior varies across tasks yet ensemble coding is stable C_LI

neuroscience↗

A novel paradigm for operant social learning in rats

The ability to learn by observing the behavior of others is both energy efficient and brings high survival value, making it an important learning tool for many species in the animal kingdom. As such, several forms of observational learning have been documented in a myriad of species. In the laboratory, rodents have proven useful models for studying different forms of observational learning, however, the most robust learning paradigms typically rely on aversive stimuli, like foot shocks, to drive the social acquisition of fear. Non-fear-based tasks have also been developed, but these rarely succeed in having observer animals perform a new behavior de novo. Consequently, much less is known regarding the cellular mechanisms supporting non-fear-based types of learning, such as visuomotor skill acquisition. To address this we developed a reward-based social learning paradigm in adult rats, in which observer animals learn to tap lit spheres in a specific sequence by watching skilled demonstrators, with successful trials leading to rewarding intracranial stimulation in both observers and performers. Following three days of observation and a 24-hour delay, observer animals outperformed control animals on several metrics of task performance and efficiency, with a subset of observers demonstrating correct performance immediately when tested. This paradigm thus introduces a novel tool to investigate the neural circuits supporting observational learning and memory for visuomotor behavior, a phenomenon about which little is understood, particularly in rodents.

animal behavior and cognition↗

Visuomotor interactions in the mouse forebrain mediated by extrastriate cortico-cortical pathways

The mammalian visual system can be broadly divided into two functional processing pathways: a dorsal stream supporting visually and spatially guided actions, and a ventral stream enabling object recognition. In rodents, the majority of visual signaling in the dorsal stream is transmitted to frontal motor cortices via extrastriate visual areas surrounding V1, but exactly where and to what extent V1 feeds into motor-projecting visual regions is not well known. To address this we employed a dual labeling strategy in male and female mice in which efferent projections from V1 were labeled anterogradely, and motor-projecting neurons in higher visual areas were labeled with retrogradely traveling adeno-associated virus (rAAV-retro) injected in M2. In flattened sections of dorsal cortex, the most pronounced colocalization V1 output and M2 input occurred in extrastriate areas AM, PM, RL and AL. Coronal sections further showed that neurons in both superficial and deep layers in these regions project to M2, but high resolution volumetric reconstructions revealed that the vast majority of putative synaptic contacts from V1 onto M2-projecting neurons occurred in layer 2/3. These findings support the existence of a dorsal processing stream in the mouse visual system, where visual signals reach motor cortex largely via feedforward projections in anteriorly and medially located extrastriate areas. Significance StatementVisually guided motor behavior depends on the long-distance relay of signals from visual cortex to frontal motor cortices, but the neuroanatomical connections linking visual and motor systems in rodents are not fully charted. Here, we characterized such pathways by injecting anterograde tracers in primary visual cortex (V1) and retrogradely traveling virus in motor cortex (M2), and visualizing where the projections overlapped. We found preferential colocalization of V1 output and M2-projecting neurons in anteriorly- and medially-located higher visual areas. 3D volumetric reconstructions further showed high rates of putative synaptic connections mainly in superficial layers. Thus, visual signals in the mouse dorsal visual stream reach motor areas at least in part via superficial, feedforward connections in a subset of extrastriate areas.

neuroscience↗