scholarly journals Positive and Negative Modulation of Motor Response in Primate Superior Colliculus by Reward Expectation

2007 ◽  
Vol 98 (6) ◽  
pp. 3163-3170 ◽  
Author(s):  
Takuro Ikeda ◽  
Okihide Hikosaka
Keyword(s):  
Superior Colliculus ◽  
Target Position ◽  
Complex Environment ◽  
Reward Schedule ◽  
Brain Areas ◽  
Appropriate Behavior ◽  
Saccade Task ◽  
Reward Information ◽  
Goal Directed Behavior ◽  
The Brain

Expectation of reward is crucial for goal-directed behavior of animals. However, little is known about how reward information is used in the brain at the time of action. We investigated this question by recording from single neurons in the macaque superior colliculus (SC) while the animal was performing a memory-guided saccade task with an asymmetrical reward schedule. The SC is an ideal structure to ask this question because it receives inputs from many brain areas including the prefrontal cortex and the basal ganglia where reward information is thought to be encoded and sends motor commands to the brain stem saccade generators. We found two groups of SC neurons that encoded reward information in the presaccadic period: positive reward-coding neurons that showed higher activity when reward was expected and negative reward-coding neurons that showed higher activity when reward was not expected. The positive reward-coding usually started even before a cue for target position was presented, whereas the negative reward-coding was largely restricted to the presaccadic period. The two kinds of reward-coding may be useful for the animal to select an appropriate behavior in a complex environment.

scholarly journals Separate Representations of Target and Timing Cue Locations in the Supplementary Eye Fields

2009 ◽  
Vol 101 (1) ◽  
pp. 448-459 ◽  
Author(s):  
Michael Campos ◽  
Boris Breznen ◽  
Richard A. Andersen
Keyword(s):  
Eye Movement ◽  
Brain Area ◽  
Target Position ◽  
Oculomotor System ◽  
Small Population ◽  
Oculomotor Control ◽  
Brain Areas ◽  
Saccade Task ◽  
Supplementary Eye Fields ◽  
The Brain

When different stimuli indicate where and when to make an eye movement, the brain areas involved in oculomotor control must selectively plan an eye movement to the stimulus that encodes the target position and also encode the information available from the timing cue. This could pose a challenge to the oculomotor system since the representation of the timing stimulus location in one brain area might be interpreted by downstream neurons as a competing motor plan. Evidence from diverse sources has suggested that the supplementary eye fields (SEF) play an important role in behavioral timing, so we recorded single-unit activity from SEF to characterize how target and timing cues are encoded in this region. Two monkeys performed a variant of the memory-guided saccade task, in which a timing stimulus was presented at a randomly chosen eccentric location. Many spatially tuned SEF neurons encoded only the location of the target and not the timing stimulus, whereas several other SEF neurons encoded the location of the timing stimulus and not the target. The SEF population therefore encoded the location of each stimulus with largely distinct neuronal subpopulations. For comparison, we recorded a small population of lateral intraparietal (LIP) neurons in the same task. We found that most LIP neurons that encoded the location of the target also encoded the location of the timing stimulus after its presentation, but selectively encoded the intended eye movement plan in advance of saccade initiation. These results suggest that SEF, by conditionally encoding the location of instructional stimuli depending on their meaning, can help identify which movement plan represented in other oculomotor structures, such as LIP, should be selected for the next eye movement.

scholarly journals Superior Colliculus-Projecting GABAergic Retinal Ganglion Cells Mediate Looming-Evoked Flight Response

2020 ◽  
Author(s):  
Xue Luo ◽  
Danrui Cai ◽  
Kejiong Shen ◽  
Qinqin Deng ◽  
Xinlan Lei ◽  
...  
Keyword(s):  
Superior Colliculus ◽  
Ganglion Cells ◽  
Flight Behavior ◽  
Mouse Retina ◽  
Retinal Ganglion ◽  
Brain Areas ◽  
Flight Response ◽  
Defensive Behaviors ◽  
The Brain ◽  
Insight Into

AbstractThe looming stimulus-evoked flight response is an experimental paradigm for studying innate defensive behaviors. However, how the visual looming stimulus is transmitted from the retina to the brain remains poorly understood. Here, we report that superior colliculus (SC)-projecting RGCs transmit the looming signal from the retina to the brain to mediate the looming-evoked flight behavior by releasing GABA. In the mouse retina, GABAergic RGCs are capable of projecting to many brain areas, including the SC. Superior colliculus (SC)-projecting GABAergic RGCs (spgRGCs) are mono-synaptically connected to the parvalbumin-positive SC neurons known to be required for the looming-evoked flight response. Optogenetic activation of spgRGCs triggers GABA-mediated inhibition in SC neurons. The ablation or silence of spgRGCs compromises looming-evoked flight response but not image-forming functions. Therefore, this study shows that spgRGCs control the looming-evoked flight response by regulating SC neurons via GABA, providing novel insight into the regulation of innate defensive behaviors.

scholarly journals The SC-SNc pathway boosts appetitive locomotion in predatory hunting

2020 ◽  
Author(s):  
Meizhu Huang ◽  
Dapeng Li ◽  
Qing Pei ◽  
Zhiyong Xie ◽  
Huating Gu ◽  
...  
Keyword(s):  
Substantia Nigra ◽  
Superior Colliculus ◽  
Dopamine Release ◽  
Dorsal Striatum ◽  
Dopamine Neurons ◽  
Substantia Nigra Pars Compacta ◽  
Locomotion Speed ◽  
Brain Circuit ◽  
Goal Directed Behavior ◽  
The Brain

ABSTRACTAppetitive locomotion is essential for organisms to approach rewards, such as food and prey. How the brain controls appetitive locomotion is poorly understood. In a naturalistic goal-directed behavior—predatory hunting, we demonstrate an excitatory brain circuit from the superior colliculus (SC) to the substantia nigra pars compacta (SNc) to boost appetitive locomotion. The SC-SNc pathway transmitted locomotion-speed signals to dopamine neurons and triggered dopamine release in the dorsal striatum. Activation of this pathway increased the speed and frequency of approach during predatory hunting, an effect that depended on the activities of SNc dopamine neurons. Conversely, synaptic inactivation of this pathway impaired appetitive locomotion but not defensive or exploratory locomotion. Together, these data revealed the SC as an important source to provide locomotion-related signals to SNc dopamine neurons to boost appetitive locomotion.

scholarly journals Compensating for a shifting world: evolving reference frames of visual and auditory signals across three multimodal brain areas

2019 ◽  
Author(s):  
Valeria C. Caruso ◽  
Daniel S. Pages ◽  
Marc A. Sommer ◽  
Jennifer M. Groh
Keyword(s):  
Superior Colliculus ◽  
Reference Frames ◽  
Brain Regions ◽  
Stimulus Onset ◽  
Visual Signals ◽  
Frontal Eye Field ◽  
Brain Areas ◽  
Initial Fixation ◽  
Auditory Signals ◽  
The Brain

ABSTRACTStimulus locations are detected differently by different sensory systems, but ultimately they yield similar percepts and behavioral responses. How the brain transcends initial differences to compute similar codes is unclear. We quantitatively compared the reference frames of two sensory modalities, vision and audition, across three interconnected brain areas involved in generating saccades, namely the frontal eye fields (FEF), lateral and medial parietal cortex (M/LIP), and superior colliculus (SC). We recorded from single neurons in head-restrained monkeys performing auditory- and visually-guided saccades from variable initial fixation locations, and evaluated whether their receptive fields were better described as eye-centered, head-centered, or hybrid (i.e. not anchored uniquely to head- or eye-orientation). We found a progression of reference frames across areas and across time, with considerable hybrid-ness and persistent differences between modalities during most epochs/brain regions. For both modalities, the SC was more eye-centered than the FEF, which in turn was more eye-centered than the predominantly hybrid M/LIP. In all three areas and temporal epochs from stimulus onset to movement, visual signals were more eye-centered than auditory signals. In the SC and FEF, auditory signals became more eye-centered at the time of the saccade than they were initially after stimulus onset, but only in the SC at the time of the saccade did the auditory signals become predominantly eye-centered. The results indicate that visual and auditory signals both undergo transformations, ultimately reaching the same final reference frame but via different dynamics across brain regions and time.New and NoteworthyModels for visual-auditory integration posit that visual signals are eye-centered throughout the brain, while auditory signals are converted from head-centered to eye-centered coordinates. We show instead that both modalities largely employ hybrid reference frames: neither fully head-nor eye-centered. Across three hubs of the oculomotor network (Intraparietal Cortex, Frontal Eye Field and Superior Colliculus) visual and auditory signals evolve from hybrid to a common eye-centered format via different dynamics across brain areas and time.

scholarly journals Short-latency allocentric control of saccadic eye movements

2017 ◽  
Vol 117 (1) ◽  
pp. 376-387 ◽  
Author(s):  
Mrinmoy Chakrabarty ◽  
Tamami Nakano ◽  
Shigeru Kitazawa
Keyword(s):  
Target Position ◽  
Saccadic Eye Movements ◽  
End Point ◽  
Saccade Control ◽  
Saccade Task ◽  
Corrective Saccade ◽  
Actual Target ◽  
Target Locations ◽  
The Brain ◽  
Direction Opposite

It is generally accepted that the neural circuits that are implicated in saccade control use retinotopically coded target locations. However, several studies have revealed that nonretinotopic representation is also used. This idea raises a question about whether nonretinotopic coding is egocentric (head or body centered) or allocentric (environment centered). In the current study, we hypothesized that allocentric coding may play a crucial role in immediate saccade control. To test this hypothesis, we used an immediate double-step saccade task toward two sequentially flashed targets with a frame in the background, and we examined whether the end point of the second saccade was affected by a transient shift of the background that participants were told to ignore. When the background was shifted transiently upward (or downward) during the flash of the second target, the second saccade generally erred the target downward (or upward), which was in the direction opposite to the shift of the background. The effect on the second saccade became significant within 150 ms after the frame was presented for decoding and was built up for 200 ms thereafter. When the second saccade was not adjusted, a small, corrective saccade followed within 300 ms. The effect scaled linearly with the shift size up to 3° for a noncorrective second saccade and up to 6° for a corrective saccade. The present results show that an allocentric location of a target is rapidly represented by the brain and used for controlling saccades. NEW & NOTEWORTHY We found that the saccade end point was shifted from the actual target position toward the direction expected from allocentric coding when a large frame in the background was transiently shifted during the period of target presentation. The effect occurred within 150 ms. The present study provides direct evidence that the brain rapidly uses allocentric coding of a target to control immediate saccades.

Ultrastructure of developing visual cortical synapses in the cat superior colliculus

1991 ◽  
Vol 49 ◽  
pp. 156-157
Author(s):  
Caroline A. Miller ◽  
Laura L. Bruce
Keyword(s):  
Superior Colliculus ◽  
Phosphate Buffer ◽  
Receptive Fields ◽  
Visual Cortical Area ◽  
Cortical Synapses ◽  
Visual Cortical ◽  
And Function ◽  
Phosphate Buffered Saline ◽  
The Brain ◽  
Cat Superior Colliculus

The first visual cortical axons arrive in the cat superior colliculus by the time of birth. Adultlike receptive fields develop slowly over several weeks following birth. The developing cortical axons go through a sequence of changes before acquiring their adultlike morphology and function. To determine how these axons interact with neurons in the colliculus, cortico-collicular axons were labeled with biocytin (an anterograde neuronal tracer) and studied with electron microscopy.Deeply anesthetized animals received 200-500 nl injections of biocytin (Sigma; 5% in phosphate buffer) in the lateral suprasylvian visual cortical area. After a 24 hr survival time, the animals were deeply anesthetized and perfused with 0.9% phosphate buffered saline followed by fixation with a solution of 1.25% glutaraldehyde and 1.0% paraformaldehyde in 0.1M phosphate buffer. The brain was sectioned transversely on a vibratome at 50 μm. The tissue was processed immediately to visualize the biocytin.

Aetiologies and anatomy of confabulation

2017 ◽  
Author(s):  
Armin Schnider
Keyword(s):  
Brain Damage ◽  
Limbic Encephalitis ◽  
Artery Aneurysm ◽  
Anterior Communicating Artery ◽  
Brain Areas ◽  
Anatomical Basis ◽  
Korsakoff Syndrome ◽  
Hypoxic Brain ◽  
Degenerative Dementia ◽  
The Brain

What diseases cause confabulations and which are the brain areas whose damage is responsible? This chapter reviews the causes, both historic and present, of confabulations and deduces the anatomo-clinical relationships for the four forms of confabulation in the following disorders: alcoholic Korsakoff syndrome, traumatic brain injury, rupture of an anterior communicating artery aneurysm, posterior circulation stroke, herpes and limbic encephalitis, hypoxic brain damage, degenerative dementia, tumours, schizophrenia, and syphilis. Overall, clinically relevant confabulation is rare. Some aetiologies have become more important over time, others have virtually disappeared. While confabulations seem to be more frequent after anterior brain damage, only one form has a distinct anatomical basis.

scholarly journals The tectonigral pathway regulates appetitive locomotion in predatory hunting in mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Meizhu Huang ◽  
Dapeng Li ◽  
Xinyu Cheng ◽  
Qing Pei ◽  
Zhiyong Xie ◽  
...  
Keyword(s):  
Substantia Nigra ◽  
Superior Colliculus ◽  
Dopamine Release ◽  
Dorsal Striatum ◽  
Dopamine Neurons ◽  
Substantia Nigra Pars Compacta ◽  
Neuronal Circuitry ◽  
Locomotion Speed ◽  
Brain Circuit ◽  
Goal Directed Behavior

AbstractAppetitive locomotion is essential for animals to approach rewards, such as food and prey. The neuronal circuitry controlling appetitive locomotion is unclear. In a goal-directed behavior—predatory hunting, we show an excitatory brain circuit from the superior colliculus (SC) to the substantia nigra pars compacta (SNc) to enhance appetitive locomotion in mice. This tectonigral pathway transmits locomotion-speed signals to dopamine neurons and triggers dopamine release in the dorsal striatum. Synaptic inactivation of this pathway impairs appetitive locomotion but not defensive locomotion. Conversely, activation of this pathway increases the speed and frequency of approach during predatory hunting, an effect that depends on the activities of SNc dopamine neurons. Together, these data reveal that the SC regulates locomotion-speed signals to SNc dopamine neurons to enhance appetitive locomotion in mice.

scholarly journals Bio-Inspired Modality Fusion for Active Speaker Detection

2021 ◽  
Vol 11 (8) ◽  
pp. 3397
Author(s):  
Gustavo Assunção ◽  
Nuno Gonçalves ◽  
Paulo Menezes
Keyword(s):  
Superior Colliculus ◽  
Visual Information ◽  
Human Beings ◽  
Validation Process ◽  
Detection Approach ◽  
Wide Range ◽  
Speaker Detection ◽  
The One ◽  
The Brain ◽  
Fusion Ability

Human beings have developed fantastic abilities to integrate information from various sensory sources exploring their inherent complementarity. Perceptual capabilities are therefore heightened, enabling, for instance, the well-known "cocktail party" and McGurk effects, i.e., speech disambiguation from a panoply of sound signals. This fusion ability is also key in refining the perception of sound source location, as in distinguishing whose voice is being heard in a group conversation. Furthermore, neuroscience has successfully identified the superior colliculus region in the brain as the one responsible for this modality fusion, with a handful of biological models having been proposed to approach its underlying neurophysiological process. Deriving inspiration from one of these models, this paper presents a methodology for effectively fusing correlated auditory and visual information for active speaker detection. Such an ability can have a wide range of applications, from teleconferencing systems to social robotics. The detection approach initially routes auditory and visual information through two specialized neural network structures. The resulting embeddings are fused via a novel layer based on the superior colliculus, whose topological structure emulates spatial neuron cross-mapping of unimodal perceptual fields. The validation process employed two publicly available datasets, with achieved results confirming and greatly surpassing initial expectations.

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