scholarly journals Direct intertectal inputs are an integral component of the bilateral sensorimotor circuit for behavior in Xenopus tadpoles

2018 ◽  
Vol 119 (5) ◽  
pp. 1947-1961 ◽  
Author(s):  
Abigail C. Gambrill ◽  
Regina L. Faulkner ◽  
Hollis T. Cline
Keyword(s):  
Optic Tectum ◽  
Visual Information ◽  
Sensory Input ◽  
Visual Experience ◽  
Visually Guided ◽  
Visuomotor Behavior ◽  
Retinal Projections ◽  
Integral Component ◽  
And Function ◽  
Circuit Function

The circuit controlling visually guided behavior in nonmammalian vertebrates, such as Xenopus tadpoles, includes retinal projections to the contralateral optic tectum, where visual information is processed, and tectal motor outputs projecting ipsilaterally to hindbrain and spinal cord. Tadpoles have an intertectal commissure whose function is unknown, but it might transfer information between the tectal lobes. Differences in visual experience between the two eyes have profound effects on the development and function of visual circuits in animals with binocular vision, but the effects on animals with fully crossed retinal projections are not clear. We tested the effect of monocular visual experience on the visuomotor circuit in Xenopus tadpoles. We show that cutting the intertectal commissure or providing visual experience to one eye (monocular visual experience) is sufficient to disrupt tectally mediated visual avoidance behavior. Monocular visual experience induces asymmetry in tectal circuit activity across the midline. Repeated exposure to monocular visual experience drives maturation of the stimulated retinotectal synapses, seen as increased AMPA-to-NMDA ratios, induces synaptic plasticity in intertectal synaptic connections, and induces bilaterally asymmetric changes in the tectal excitation-to-inhibition ratio (E/I). We show that unilateral expression of peptides that interfere with AMPA or GABAA receptor trafficking alters E/I in the transfected tectum and is sufficient to degrade visuomotor behavior. Our study demonstrates that monocular visual experience in animals with fully crossed visual systems produces asymmetric circuit function across the midline and degrades visuomotor behavior. The data further suggest that intertectal inputs are an integral component of a bilateral visuomotor circuit critical for behavior. NEW & NOTEWORTHY The developing optic tectum of Xenopus tadpoles represents a unique circuit in which laterally positioned eyes provide sensory input to a circuit that is transiently monocular, but which will be binocular in the animal’s adulthood. We challenge the idea that the two lobes of tadpole optic tectum function independently by testing the requirement of interhemispheric communication and demonstrate that unbalanced sensory input can induce structural and functional plasticity in the tectum sufficient to disrupt function.

scholarly journals Investigating the Subcortical Route to the Amygdala Across Species and in Disordered Fear Responses

2019 ◽  
Vol 13 ◽  
pp. 117906951984644 ◽  
Author(s):  
Jessica McFadyen
Keyword(s):  
Visual Information ◽  
Sensory Input ◽  
Cortical Circuits ◽  
Temporal Area ◽  
Middle Temporal ◽  
Directional Flow ◽  
The Past ◽  
And Function ◽  
Anatomical Evidence

Over the past few decades, evidence has come to light that there is a rapid subcortical shortcut that transmits visual information to the amygdala, effectively bypassing the visual cortex. This pathway purportedly runs from the superior colliculus to the amygdala via the pulvinar, and thus presents a methodological challenge to study noninvasively in the human brain. Here, we present our recent work where we reliably reconstructed the white matter structure and directional flow of neural signal along this pathway in over 600 healthy young adults. Critically, we found structure-function relationships for the pulvinar-amygdala connection, where people with greater fibre density had stronger functional neural coupling and were also better at recognising fearful facial expressions. These results tie together recent anatomical evidence from other visual primates with very recent optogenetic research on rodents demonstrating a functional role of this pathway in producing fear responses. Here, we discuss how this pathway might operate alongside other thalamo-cortical circuits (such as pulvinar to middle temporal area) and how its structure and function may change according to the sensory input it receives. This newly established circuit might play a potentially important role in autism and/or anxiety disorders.

Dynamics of visually guided auditory plasticity in the optic tectum of the barn owl

1995 ◽  
Vol 73 (2) ◽  
pp. 595-614 ◽  
Author(s):  
M. S. Brainard ◽  
E. I. Knudsen
Keyword(s):  
Visual Field ◽  
Optic Tectum ◽  
Visual Experience ◽  
Normal Values ◽  
Interaural Time Difference ◽  
Receptive Fields ◽  
Visually Guided ◽  
Barn Owls ◽  
Tectal Neurons ◽  
The Right

1. In the optic tectum of normal barn owls, bimodal (auditory-visual) neurons are tuned to the values of interaural time difference (ITD) that are produced by sounds at the locations of their visual receptive fields (VRFs). The auditory tuning of tectal neurons is actively guided by visual experience during development: in the tectum of adult owls reared with an optically displaced visual field, neurons are tuned to abnormal values of ITD that are close to the values produced by sounds at the locations of their optically displaced VRFs. In this study we investigated the dynamics of this experience-dependent plasticity. 2. Owls were raised from shortly after eye-opening (14-22 days of age) with prismatic spectacles that displaced the visual field to the right or left. Starting at approximately 60 days of age, multiunit recordings were made to assess the tuning of tectal neurons to ITD presented via earphones. In the earliest recording sessions (ages 60-80 days), ITD tuning was often close to normal, even though the majority of the owls' previous experience was with an altered correspondence between ITD values and VRF locations. Subsequently, over a period of weeks, responses to the normal range of ITDs were gradually eliminated while responses to values of ITD corresponding with the optically displaced VRF were acquired. 3. At intermediate stages in this process, the ITD tuning at many sites became abnormally broad, so that responses were simultaneously present to both normal values of ITD and to values corresponding with the optically displaced VRF. At this stage the latencies and durations of newly acquired responses systematically exceeded the latencies and durations of the responses to normal values of ITD. 4. Dynamic changes in ITD tuning similar to those recorded in the optic tectum also occurred in the external nucleus of the inferior colliculus (ICX), which provides the major source of ascending auditory input to the tectum. 5. These results suggest the hypothesis that the neural selectivity for ITD in the barn owl's tectum is first established by vision-independent mechanisms and only subsequently calibrated by visual experience. This calibration involves both the elimination of responses to normal values of ITD and the visually guided acquisition of responses to novel values and can be accounted for by plasticity at the level of the ICX.

scholarly journals Collicular Vision Guides Nonconscious Behavior

2010 ◽  
Vol 22 (5) ◽  
pp. 888-902 ◽  
Author(s):  
Marco Tamietto ◽  
Franco Cauda ◽  
Luca Latini Corazzini ◽  
Silvia Savazzi ◽  
Carlo A. Marzi ◽  
...  
Keyword(s):  
Visual Experience ◽  
Striate Cortex ◽  
Visual Signals ◽  
Visually Guided ◽  
Visuomotor Integration ◽  
Motor Processing ◽  
Pupillary Responses ◽  
Cortex Area ◽  
Extrastriate Areas

Following destruction or deafferentation of primary visual cortex (area V1, striate cortex), clinical blindness ensues, but residual visual functions may, nevertheless, persist without perceptual consciousness (a condition termed blindsight). The study of patients with such lesions thus offers a unique opportunity to investigate what visual capacities are mediated by the extrastriate pathways that bypass V1. Here we provide evidence for a crucial role of the collicular–extrastriate pathway in nonconscious visuomotor integration by showing that, in the absence of V1, the superior colliculus (SC) is essential to translate visual signals that cannot be consciously perceived into motor outputs. We found that a gray stimulus presented in the blind field of a patient with unilateral V1 loss, although not consciously seen, can influence his behavioral and pupillary responses to consciously perceived stimuli in the intact field (implicit bilateral summation). Notably, this effect was accompanied by selective activations in the SC and in occipito-temporal extrastriate areas. However, when instead of gray stimuli we presented purple stimuli, which predominantly draw on S-cones and are thus invisible to the SC, any evidence of implicit visuomotor integration disappeared and activations in the SC dropped significantly. The present findings show that the SC acts as an interface between sensory and motor processing in the human brain, thereby providing a contribution to visually guided behavior that may remain functionally and anatomically segregated from the geniculo-striate pathway and entirely outside conscious visual experience.

scholarly journals Insect photoreceptor adaptations to night vision

2017 ◽  
Vol 372 (1717) ◽  
pp. 20160077 ◽  
Author(s):  
Anna Honkanen ◽  
Esa-Ville Immonen ◽  
Iikka Salmela ◽  
Kyösti Heimonen ◽  
Matti Weckström
Keyword(s):  
Visual Information ◽  
Insect Vision ◽  
Night Vision ◽  
Single Photons ◽  
Visually Guided ◽  
Neural Signals ◽  
Light Responses ◽  
Anatomical Structures ◽  
Retinal Photoreceptors ◽  
Physiological Adaptations

Night vision is ultimately about extracting information from a noisy visual input. Several species of nocturnal insects exhibit complex visually guided behaviour in conditions where most animals are practically blind. The compound eyes of nocturnal insects produce strong responses to single photons and process them into meaningful neural signals, which are amplified by specialized neuroanatomical structures. While a lot is known about the light responses and the anatomical structures that promote pooling of responses to increase sensitivity, there is still a dearth of knowledge on the physiology of night vision. Retinal photoreceptors form the first bottleneck for the transfer of visual information. In this review, we cover the basics of what is known about physiological adaptations of insect photoreceptors for low-light vision. We will also discuss major enigmas of some of the functional properties of nocturnal photoreceptors, and describe recent advances in methodologies that may help to solve them and broaden the field of insect vision research to new model animals. This article is part of the themed issue ‘Vision in dim light’.

scholarly journals Zebrafish Dscaml1 is Essential for Retinal Patterning and Function of Oculomotor Subcircuits

2019 ◽  
Author(s):  
Manxiu Ma ◽  
Alexandro D. Ramirez ◽  
Tong Wang ◽  
Rachel L. Roberts ◽  
Katherine E. Harmon ◽  
...  
Keyword(s):  
Animal Model ◽  
Light Adaptation ◽  
Neural Circuit ◽  
Oculomotor System ◽  
Gaze Stabilization ◽  
Ocular Disorders ◽  
Motor Apraxia ◽  
Premotor Pathways ◽  
And Function ◽  
Circuit Function

AbstractDown Syndrome Cell Adhesion Molecules (dscam and dscaml1) are essential regulators of neural circuit assembly, but their roles in vertebrate neural circuit function are still mostly unexplored. We investigated the role of dscaml1 in the zebrafish oculomotor system, where behavior, circuit function, and neuronal activity can be precisely quantified. Loss of zebrafish dscaml1 resulted in deficits in retinal patterning and light adaptation, consistent with its known roles in mammals. Oculomotor analyses showed that mutants have abnormal gaze stabilization, impaired fixation, disconjugation, and faster fatigue. Notably, the saccade and fatigue phenotypes in dscaml1 mutants are reminiscent of human ocular motor apraxia, for which no animal model exists. Two-photon calcium imaging showed that loss of dscaml1 leads to impairment in the saccadic premotor pathway but not the pretectum-vestibular premotor pathway, indicating a subcircuit requirement for dscaml1. Together, we show that dscaml1 has both broad and specific roles in oculomotor circuit function, providing a new animal model to investigate the development of premotor pathways and their associated human ocular disorders.

scholarly journals Aberrant information transfer interferes with functional axon regeneration

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Chen Ding ◽  
Marc Hammarlund
Keyword(s):  
Information Transfer ◽  
Synapse Formation ◽  
Axon Regeneration ◽  
Behavioral Recovery ◽  
Axon Injury ◽  
Functional Regeneration ◽  
Key Variables ◽  
And Function ◽  
Circuit Function ◽  
Molecular Components

Functional axon regeneration requires regenerating neurons to restore appropriate synaptic connectivity and circuit function. To model this process, we developed an assay in Caenorhabditis elegans that links axon and synapse regeneration of a single neuron to recovery of behavior. After axon injury and regeneration of the DA9 neuron, synapses reform at their pre-injury location. However, these regenerated synapses often lack key molecular components. Further, synaptic vesicles accumulate in the dendrite in response to axon injury. Dendritic vesicle release results in information misrouting that suppresses behavioral recovery. Dendritic synapse formation depends on dynein and jnk-1. But even when information transfer is corrected, axonal synapses fail to adequately transmit information. Our study reveals unexpected plasticity during functional regeneration. Regeneration of the axon is not sufficient for the reformation of correct neuronal circuits after injury. Rather, synapse reformation and function are also key variables, and manipulation of circuit reformation improves behavioral recovery.

scholarly journals Working memory gates visual input to primate prefrontal neurons

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Behrad Noudoost ◽  
Kelsey Lynne Clark ◽  
Tirin Moore
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Sensory Input ◽  
Neural Circuits ◽  
Visual Input ◽  
Visually Guided ◽  
Visual Neurons ◽  
Cortical Inputs ◽  
Behaving Monkeys ◽  
Visual Cortical

Visually guided behavior relies on the integration of sensory input and information held in working memory (WM). Yet it remains unclear how this is accomplished at the level of neural circuits. We studied the direct visual cortical inputs to neurons within a visuomotor area of prefrontal cortex in behaving monkeys. We show that the efficacy of visual input to prefrontal cortex is gated by information held in WM. Surprisingly, visual input to prefrontal neurons was found to target those with both visual and motor properties, rather than preferentially targeting other visual neurons. Furthermore, activity evoked from visual cortex was larger in magnitude, more synchronous, and more rapid, when monkeys remembered locations that matched the location of visual input. These results indicate that WM directly influences the circuitry that transforms visual input into visually guided behavior.

Blindsight and the Role of the Phenomenal Qualities of Visual Perceptions

1998 ◽  
pp. 205-209
Author(s):  
Ralph Schumacher
Keyword(s):  
Visual Perception ◽  
Visual Information ◽  
Visual Experience ◽  
Sufficient Condition ◽  
Broad Concept ◽  
Essential Properties

The aim of this paper is to defend a broad concept of visual perception, according to which it is a sufficient condition for visual perception that subjects receive visual information in a way which enables them to give reliably correct answers about the objects presented to them. According to this view, blindsight, non-epistemic seeing, and conscious visual experience count as proper types of visual perception. This leads to two consequences concerning the role of the phenomenal qualities of visual experiences. First, phenomenal qualities are not necessary in order to see something, because in the case of blindsight, subjects can see objects without experiences phenomenal qualities. Second, they cannot be intentional properties, since they are not essential properties of visual experiences, and because the content of visual experiences cannot be constituted by contingent properties.

Difficult Turned Easy: Suggestion Renders a Challenging Visual Task Simple

2020 ◽  
pp. 095679762095485
Author(s):  
Mathieu Landry ◽  
Jason Da Silva Castanheira ◽  
Jérôme Sackur ◽  
Amir Raz
Keyword(s):  
Mental Imagery ◽  
Visual Information ◽  
Perceptual Experience ◽  
Sensory Input ◽  
Moving Objects ◽  
Visual Stimuli ◽  
Perceptual Information ◽  
Hypnotic Suggestion ◽  
Adult Participants ◽  
The Brain

Suggestions can cause some individuals to miss or disregard existing visual stimuli, but can they infuse sensory input with nonexistent information? Although several prominent theories of hypnotic suggestion propose that mental imagery can change our perceptual experience, data to support this stance remain sparse. The present study addressed this lacuna, showing how suggesting the presence of physically absent, yet critical, visual information transforms an otherwise difficult task into an easy one. Here, we show how adult participants who are highly susceptible to hypnotic suggestion successfully hallucinated visual occluders on top of moving objects. Our findings support the idea that, at least in some people, suggestions can add perceptual information to sensory input. This observation adds meaningful weight to theoretical, clinical, and applied aspects of the brain and psychological sciences.

scholarly journals Spontaneous activations follow a common developmental course across primary sensory areas in mouse neocortex

2016 ◽  
Vol 116 (2) ◽  
pp. 431-437 ◽  
Author(s):  
Charles G. Frye ◽  
Jason N. MacLean
Keyword(s):  
Calcium Imaging ◽  
Sensory Input ◽  
Primary Auditory Cortex ◽  
Developmental Trajectory ◽  
Two Photon ◽  
Developmental Progression ◽  
Sensory Modalities ◽  
Spatially Distributed ◽  
And Function ◽  
Insight Into

Spontaneous propagation of spiking within the local neocortical circuits of mature primary sensory areas is highly nonrandom, engaging specific sets of interconnected and functionally related neurons. These spontaneous activations promise insight into neocortical structure and function, but their properties in the first 2 wk of perinatal development are incompletely characterized. Previously, we have found that there is a minimal numerical sample, on the order of 400 cells, necessary to fully capture mature neocortical circuit dynamics. Therefore we maximized our numerical sample by using two-photon calcium imaging to observe spontaneous activity in populations of up to 1,062 neurons spanning multiple columns and layers in 52 acute coronal slices of mouse neocortex at each day from postnatal day (PND) 3 to PND 15. Slices contained either primary auditory cortex (A1) or somatosensory barrel field (S1BF), which allowed us to compare sensory modalities with markedly different developmental timelines. Between PND 3 and PND 8, populations in both areas exhibited activations of anatomically compact subgroups on the order of dozens of cells. Between PND 9 and PND 13, the spatiotemporal structure of the activity diversified to include spatially distributed activations encompassing hundreds of cells. Sparse activations covering the entire field of view dominated in slices taken on or after PND 14. These and other findings demonstrate that the developmental progression of spontaneous activations from active local modules in the first postnatal week to sparse, intermingled groups of neurons at the beginning of the third postnatal week generalizes across primary sensory areas, consistent with an intrinsic developmental trajectory independent of sensory input.

Sign in / Sign up

Export Citation Format

Share Document