Multimodal tracking of motor activity, sleep and mood
This talk will (1) describe patterns and correlates of objectively assessed motor activity (2) present findings on the inter-relationships among motor activity, sleep and circadian rhythms and mood disorders; (3) describe potential of cross species studies of motor activity and related systems to inform human chronobiology research
Visual and cross-modal plasticity in adult humans
Neuroplasticity is a fundamental property of the nervous system that is maximal early in life, within a specific temporal window called critical period. However, it is still unclear to which extent the plastic potential of the visual cortex is retained in adulthood. We have surprisingly revealed residual ocular dominance plasticity in adult humans by showing that short-term monocular deprivation unexpectedly boosts the deprived eye (both at the perceptual and at the neural level), reflecting homeostatic plasticity. This effect is accompanied by a decrease of GABAergic inhibition in the primary visual cortex and can be modulated by non-visual factors (motor activity and motor plasticity). Finally, we have found that cross-modal plasticity is preserved in adult normal-sighted humans, as short-term monocular deprivation can alter early visuo-tactile interactions. Taken together, these results challenge the classical view of a hard-wired adult visual cortex, indicating that homeostatic plasticity can be reactivated in adult humans.
State-dependent cortical circuits
Spontaneous and sensory-evoked cortical activity is highly state-dependent, promoting the functional flexibility of cortical circuits underlying perception and cognition. Using neural recordings in combination with behavioral state monitoring, we find that arousal and motor activity have complementary roles in regulating local cortical operations, providing dynamic control of sensory encoding. These changes in encoding are linked to altered performance on perceptual tasks. Neuromodulators, such as acetylcholine, may regulate this state-dependent flexibility of cortical network function. We therefore recently developed an approach for dual mesoscopic imaging of acetylcholine release and neural activity across the entire cortical mantle in behaving mice. We find spatiotemporally heterogeneous patterns of cholinergic signaling across the cortex. Transitions between distinct behavioral states reorganize the structure of large-scale cortico-cortical networks and differentially regulate the relationship between cholinergic signals and neural activity. Together, our findings suggest dynamic state-dependent regulation of cortical network operations at the levels of both local and large-scale circuits. Zoom Meeting ID: 964 8138 3003 Contact host if you cannot connect.
State-dependent cortical circuits
Spontaneous and sensory-evoked cortical activity is highly state-dependent, promoting the functional flexibility of cortical circuits underlying perception and cognition. Using neural recordings in combination with behavioral state monitoring, we find that arousal and motor activity have complementary roles in regulating local cortical operations, providing dynamic control of sensory encoding. These changes in encoding are linked to altered performance on perceptual tasks. Neuromodulators, such as acetylcholine, may regulate this state-dependent flexibility of cortical network function. We therefore recently developed an approach for dual mesoscopic imaging of acetylcholine release and neural activity across the entire cortical mantle in behaving mice. We find spatiotemporally heterogeneous patterns of cholinergic signaling across the cortex. Transitions between distinct behavioral states reorganize the structure of large-scale cortico-cortical networks and differentially regulate the relationship between cholinergic signals and neural activity. Together, our findings suggest dynamic state-dependent regulation of cortical network operations at the levels of both local and large-scale circuits.
Neural Mechanisms of Coordination in Duetting Wrens
To communicate effectively, two individuals must take turns to prevent overlap in their signals. How does the nervous system coordinate vocalizations between two individuals? Female and male plain-tailed wrens sing a duet in which they alternate syllable production so rapidly and precisely it sounds as if a single bird is singing. I will talk about experiments that examine the interaction between sensory cues and motor activity, using behavioral manipulations and neurophysiological recordings from pairs of awake, duetting wrens. I will show evidence that auditory cues link the brains of the wrens by modulating motor circuits.
The active modulation of sound and vibration perception
The dominant view of perception right now is that information travels from the environment to the sensory system, then to the nervous systems which processes it to generate a percept and behaviour. Ongoing behaviour is thought to occur largely through simple iterations of this process. However, this linear view, where information flows only in one direction and the properties of the environment and the sensory system remain static and unaffected by behaviour, is slowly fading. Many of us are beginning to appreciate that perception is largely active, i.e. that information flows back and forth between the three systems modulating their respective properties. In other words, in the real world, the environment and sensorimotor loop is pretty much always closed. I study the loop; in particular I study how the reverse arm of the loop affects sound and vibration perception. I will present two examples of motor modulation of perception at two very different temporal and spatial scales. First, in crickets, I will present data on how high-speed molecular motor activity enhances hearing via the well-studied phenomenon of active amplification. Second, in spiders I will present data on how body posture, a slow macroscopic feature, which can barely be called ‘active’, can nonetheless modulate vibration perception. I hope these results will motivate a conversation about whether ‘active’ perception is an optional feature observed in some sensory systems, or something that is ultimately necessitated by both evolution and physics.