Calcium activity

A long-standing premise in theoretical neuroscience holds that the complex interactions between neurons or, at a different systems level, between networks in the nervous system can be expressed in terms of an underlying system of nonlinear dynamics. A classical approach has been dynamical systems theory, whereby biophysical processes in the brain can be naturally formalized in terms of differential equations (ODEs) that may be capable of offering an explicit and interpretable account of how different biochemical and physiological processes in the brain evolve to produce the complex repertoire

…complex spatiotemporal patterns of calcium activity during animal behavior. The properties, mechanisms, and physiological relevance of these patterns are still poorly understood. Here, we performed two-photon calcium imaging in cortical astrocytes expressing cyto-GCaMP6f in head-fixed mice running on a rotating platform. In each imaging frame, suprathreshold calcium activity regions (segments of spatiotemporal calcium events) were detected. We analyzed ΔF/F, total active area, mean segment area, and segment density during

…LIDs result from abnormal striatal activity, yet how this activity affects downstream BG circuits to generate LIDs

During decision-making, sensory input is integrated with internal priors to produce appropriate action. Theoretical work has proposed a hierarchical implementation of this process in visual cortex (Rao & Ballard 1999), but it remains unclear whether and how networks of visual cortical neurons might encode priors in a predictive manner. To investigate this, we trained mice on a standardised behavioural platform for visual decision-making (The International Brain Laboratory, 2023): mice turned a wheel to indicate whether a visual grating appeared on the left or the right, with prior probabil

…To test whether S1-CSNs activity is modulat

…hippocampus and thalamus alongside calcium activity via GCaMP6F in cortical neurons in triple-transgenic animals or in hippocampal astrocytes via viral transduction are brought to bear to reveal hitherto inaccessible and under-appreciated a

Miniature head-mounted microscopes have enabled in vivo optical measurements of neural activity in freely moving animals, allowing neuroscientists to study the neural basis of behaviors that are difficult to recapitulate in head-fixed preparations like social interaction and navigation. Existing head-mounted microscopes for small animals are limited to small fields of view (< 1mm2), which limit the number of neurons that can be recorded simultaneously to at most several hundred. However, understanding how behavior is controlled by large neural populations across brain regions requires simul

…Disruption in the rhythmic activity of glucocorticoids has been observed in individuals with a variety of cancer types, and blunting of this rhythm has been shown to predict cancer mortality and declines in quality of life. This suggests that a disrupted glucocorticoid rhythm is potentially a shared phenotype across cancers. However, where this phenomenon is driven by the cancer itself, and the causal mechanisms that link glucocorticoid rhythm dysfunction and c

…been made in understanding how neural activity in specific cortical regions contributes to behavior. However, there is a lack of tools that allow simultaneous monitoring and perturbing neural activity from multiple cortical regions. We have engineered a suite of technologies to enable easy, robust access to much of the dorsal cortex of mice for optical and electrophysiological recordings. First, I will describe microsurgery robots that can programmed to perform

…the recurrence of a pattern of neural activity during sleep or quiet waking that previously occurred during a sensory experience. Historically, reactivations have been studied in the hippocampus. However, whether reactivations in sensory cortex depend on local activation of neurons during prior experience is not well understood. We hypothesize that such reactivations in sensory association cortex could be important for learnin

Long-term potentiation (LTP) is thought to be a key plasticity mechanism underlying the formation and maintenance of hippocampal place codes. It is unclear, however, which properties of these neural codes are inherited from upstream processing and which are learned through plasticity. To disentangle these influences on place codes, we utilized a method for abolishing LTP specifically in hippocampal region CA1 of the adult mouse without affecting basal synaptic processing: conditional genetic deletion of a necessary component of the postsynaptic membrane fusion machinery, Syntaxin3 (Stx3). Surp

…been made in understanding how neural activity in specific cortical regions contributes to behavior. However, there is a lack of tools that allow simultaneous monitoring and perturbing neural activity from multiple cortical regions. We have engineered a suite of technologies to enable easy, robust access to much of the dorsal cortex of mice for optical and electrophysiological recordings. First, I will describe microsurgery robots that can programmed to perform

The dynamic nature of sleep in most animals suggests distinct stages which serve different functions. Genetic sleep induction methods in animal models provide a powerful way to disambiguate these stages and functions, although behavioural methods alone are insufficient to accurately identify what kind of sleep is being engaged. In Drosophila, activation of the dorsal fan-shaped body (dFB) promotes sleep, but it remains unclear what kind of sleep this is, how the rest of the fly brain is behaving, or if any specific sleep functions are being achieved. Here, we developed a method to record calci