Superior colliculus

Neuronal activity in the primate superior colliculus (SC) is modulated by physical salience, reward value, and attention, but how these signals are integrated remains unknown. One hypothesis is that SC activity reflects a unified “priority map” of the visual field. However, it is unclear how a unified priority map might support distinct roles for SC activity in different contexts: If the same SC neurons are activated by saccade cues and attention cues, how can SC activity evoke a saccade in one context but covert orienting of attention in another context? We hypothesized that distinct sources

…The superior colliculus and dorsal periaqueductal gray (dPAG) play a crucial role in the neural circuitry responsible for processing threatening cues and triggering escape responses. However, th

…and subcortical structures (thalamus; superior colliculus, SC), each with distinct functional properties and cellular compositions. However, the precise distribution of behaviorally relevant visual signals across these pathways remains unclear, a

The primary visual cortex (V1) directly projects to the superior colliculus (SC) and is believed to provide sensory drive for eye movements. Consistent with this, a majority of saccade-related SC neurons also exhibit short-latency, stimulus-driven visual responses, which are additionally feature-tuned. However, direct neurophysiological comparisons of the visual response properties of the two anatomically-connected brain areas are surprisingly lacking, especially with respect to active looking behaviors. I will describe a series of experiments characterizing visual response properties in prima

Characterizing feature selectivities of sensory visual neurons is crucial for understanding how the brain forms representations of the external world. In vivo neurophysiological experiments aimed at identifying such tuning properties are constrained by time, making exhaustive searches in stimulus space infeasible. In recent years, deep neural networks (DNNs) have set new standards in predicting neuronal responses of the visual system to arbitrary stimuli, making in silico exploration of the stimulus-response space possible. As visual input is dynamic, there is a need for models that can faithf

…remains poorly explored in the superior colliculus (SC), a central structure of the mouse visual system. We here report that astrocytes from the retinorecipient layers of the SC form particularly extensive networks that are mediated by stronger expression of the gap-junction connexins 30 and 43, compared to astrocytes from other brain areas. Furthermore,

…Here we focused on the superior colliculus and performed in vivo two-photon calcium imaging while the mice were engaged in an implicit visual learning task. Following the Bayesian learning principles, wild-type mice showed contextual modulation of the visual responses in the superior colliculus and pupil dynamics, but not in the retinal signals. In contrast, Scn2a-haploinsufficient autism model mice exhibited anomalous modulati

…Many neurons in the mouse superior colliculus, a direct target of the retina, preferentially respond to stimuli moving in one direction, but not the opposite, with diverse direction preferences across populations. Such

Animals swiftly react to environmental stimuli, with the involvement of the superior colliculus (SC). While the SC is playing a pivotal role in coordinating innate behaviors such as coordinating orientation and defense responses, its involvement in the somatosensory system remains relatively unexplored. Our recent research has unveiled the connectivity between mouse whisker-circuits and the SC, including pathways from the motor cortex (MC), barrel field of S1 (BC), and brainstem (Bs). Mapping the whisker-sensitive region of the SC in mice revealed a novel trans-collicular connectivity motif, w

Locomotion initiation and speed control are dependent on activity in the Mesencephalic Locomotor Region (MLR). In mammals the MLR is constituted of glutamatergic neurons in the pedunculopontine nucleus (PPN) and cuneiform nucleus (CnF) that act together to control locomotion speed. To further understand their contribution in the context of sensory evoked locomotor behaviour, we asked how visually evoked locomotor escape responses in mice are modulated by MLR. To evoke natural escape we used innate looming responses. Using chemogenetic inhibition of targeted Vglut2+ glutamatergic neurons in PPN

How does the visual system adapt when the amount of light in the scene changes, such as when an animal leaves a shaded area or when night turns to day? As light levels increase and the relative amount of noise in the scene decreases, efficient coding theory predicts a transition in sensory processing. At low light levels, sensory systems should integrate spatial and temporal information, while at high light levels, neural processing should differentiate incoming signals to subtract predictive components. Previous experimental work has shown that, indeed, the center-surround structure of spatia

Extraction of relevant stimulus features from the dynamic sensory scene needs to be coupled to the execution of appropriate adaptive responses to ensure survival. A predator needs to evaluate its position with respect to that of moving prey, define an approach strategy and carry out the proper motor commands to execute it. The most efficient strategy will require an estimation of the future position of the target and should account for the predator’s sensorimotor processing delays to make a predictive interception. Mice can hunt moving prey and have been established as a successful model to st

The pathway descending from the superior colliculus (SC) to the dopaminergic (DA) neurons within the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) is involved in controlling an animal’s orienting movements based on sensory integration. Most studies to date have focused only on the dominant, ipsilateral branch of this pathway, although there are both monosynaptic and polysynaptic contralateral connections descending from the SC to the ventral midbrain. Therefore, we set out to characterise the responses of DA neurons in the VTA/SNc to lateralized retinal stimulation and

…impacts visual adaptation in the superior colliculus (SC), the most prominent visual centre in mice, which integrates retinal input in its superficial layers and performs sensorimotor transformations in its deeper layers. We r

…motor cortex (ALM) and the superior colliculus (SC) are important parts of a cortico-subcortical loop that transforms multisensory inputs into behavioral decisions. To study the role of these areas in multisensory integration and decision-making, we trained mice in a multisensory discrimination task, where animals had to integrate visu

The Superior Colliculus (SC) is a highly conserved midbrain organ implicated in sensorimotor integration. Pitx2on neurons are a recently identified population of glutamatergic neurons in the intermediate SC, whose activation leads to spatially oriented head movements. Viral tracing of these output neurons revealed a plethora of input and output regions. Particularly, while Pitx2on neurons project to tecto-spinal systems, traditionally associated with the control of head and eye movements, they also target the mesocorticolimbic system, suggesting a possible role of these neurons going beyond mo

…brainstem structures, such as the Superior Colliculus (SC), which plays a pivotal role in fixation maintenance and saccade programming, exhibit neurofibrillary changes sooner than cortical regions (Uematsu et al., 2018) and is susceptible to tau pathology and neuronal loss in AD patients. Accordingly, eye movement abnormalities associated with AD are often observed durin

The superior colliculus (SC) is a dorsal midbrain structure known for its roles in multisensory integration and motor responses and its dysfunction has been linked to neurodevelopmental diseases. SC is a highly organized structure composed of distinct laminae of diverse neuronal and glial cell types. However, the precise developmental principles instructing the generation of SC cell-type diversity are still unknown. To investigate this, we pursued lineage tracing using genetic MADM (Mosaic Analysis with Double Markers)-based clonal analysis with single cell sequencing (MADM-CloneSeq) and in si

…to be critically dependent on the superior colliculus (SC). Evidence for this comes from local single-unit recordings that reveal a spatial organisation of visual and behavioural representations. However, the broader population dynamics and mechanisms orchest

…on IO afferents from the superior colliculus (SC), crucial for orienting behavior, we identified a novel target area f

…The superior colliculus (SC) plays a crucial role in integrating visual perception and oculomotor functions, and recent observations in the R6/1 HD mouse model from our group indicate affected connectivity between the M2 motor cortex (M2) and SC. To comprehensively assess changes in HD pathophysiology, we conducted fMRI-based functional connectivity analysis in 17-week

…of audio-visual delays in the mouse superior co

…axons as well as local neurons in the superior colliculus (SC), we performed functional mapping of the retinocollicular projection at a single-cell resolution in awake mice. The tiling patterns of RGC axon terminals and their corresponding receptive

Microsaccades are small (<1°) fixational eye movements. Spatial biases in microsaccade direction reflect the focus of covert attentional selection [1]. Yet, whether microsaccades and covert attention are mediated by shared, or distinct, neural mechanisms remains actively debated [2-4]. For example, a recent study suggested that attentional modulations of neural activity in visual area V4 occur only when accompanied by microsaccades [2]. Yet, other studies have shown that behavioral and neural effects of attention occur regardless of microsaccades [3-4]. Here, we present novel evidence that