Organization of sensory input of command neurons

1983 ◽  
Vol 13 (4) ◽  
pp. 269-274 ◽  
Author(s):  
N. I. Bravarenko ◽  
P. M. Balaban ◽  
E. N. Sokolov
Keyword(s):  
Sensory Input ◽  
Command Neurons

Divergent Connectivity of Homologous Command Neurons Mediates Segment-Specific Touch Responses in Drosophila

2018 ◽  
Author(s):  
Suguru Takagi ◽  
Benjamin Thomas Cocanougher ◽  
Sawako Niki ◽  
Dohjin Miyamoto ◽  
Hiroshi Kohsaka ◽  
...  
Keyword(s):  
Command Neurons

Activity, Agency, and Inner Speech Pathology

2018 ◽  
Author(s):  
Lauren Swiney
Keyword(s):  
Motor Control ◽  
Sensory Input ◽  
The Other ◽  
Predictive Processing ◽  
Inner Speech ◽  
Speech Pathology ◽  
Active Inference ◽  
Comparator Hypothesis

Over the last thirty years the comparator hypothesis has emerged as a prominent account of inner speech pathology. This chapter discusses a number of cognitive accounts broadly derived from this approach, highlighting the existence of two importantly distinct notions of inner speech in the literature; one as a prediction in the absence of sensory input, the other as an act with sensory consequences that are themselves predicted. Under earlier frameworks in which inner speech is described in the context of classic models of motor control, I argue that these two notions may be compatible, providing two routes to inner speech pathology. Under more recent accounts grounded in the architecture of Bayesian predictive processing, I argue that “active inference” approaches to action generation pose serious challenges to the plausibility of the latter notion of inner speech, while providing the former notion with rich explanatory possibilities for inner speech pathology.

The mamillothalamic pathways: my first encounter with the thalamus

2017 ◽  
Author(s):  
Ray Guillery
Keyword(s):  
Sensory Input ◽  
Great Success ◽  
Cortical Lesions ◽  
Head Direction ◽  
Thalamic Nuclei ◽  
Sensory Pathways ◽  
Cortical Areas ◽  
Thalamic Relay ◽  
The Many

My thesis studies had stimulated an interest in the mamillothalamic pathways but also some puzzlement because we knew nothing about the nature of the messages passing along these pathways. Several laboratories were studying the thalamic relay of sensory pathways with great success during my post-doctoral years. Each sensory relay could be understood in terms of the appropriate sensory input, but we had no way of knowing the meaning of the mamillothalamic messages. I introduce these nuclei as an example of the many thalamic nuclei about whose input functions we still know little or nothing. Early clinical studies of mamillary lesions had suggested a role in memory formation, whereas evidence from cortical lesions suggested a role in emotional experiences. Studies of the smallest of the three nuclei forming these pathways then showed it to be concerned with sensing head direction, relevant but not sufficient for defining an animal’s position in space. More recent studies based on studies of cortical activity or cortical damage have provided a plethora of suggestions: as so often, the answers reported depend on the questions asked. That simple conclusion is relevant for all transthalamic pathways. The evidence introduced in Chapter 1, that thalamocortical messages have dual meanings, suggests that we need to rethink our questions. It may prove useful to look at the motor outputs of relevant cortical areas to get clues about some appropriate questions.

Presence, Environment, and Sound and the Role of Imagination

2019 ◽  
pp. 667-681
Author(s):  
Mark Grimshaw-Aagaard
Keyword(s):  
Computer Games ◽  
Virtual World ◽  
Actual World ◽  
Sensory Input ◽  
The World ◽  
Visual Dimension ◽  
The Creation ◽  
First Person Shooter ◽  
Selection Of

Mark Grimshaw-Aagaard addresses the role of sound in the creation of presence in virtual and actual worlds. He argues that imagination is a central part of the generation and selection of perceptual hypotheses—models of the world in which we can act—that emerge from what Grimshaw-Aagaard calls the “exo-environment” (the sensory input) and the “endo-environment” (the cognitive input). Grimshaw-Aagaard further divides the exo-environment into a primarily auditory and a primarily visual dimension and he deals with the actual world of his own apartment and the virtual world of first-person-shooter computer games in order to exemplify how we perceptually construct an environment that allows for the creation of presence.

Stimulus Generalization Using Nonvisual Stimuli with a Student Who Has Autism Spectrum Disorder and Visual Impairment

2021 ◽  
Vol 115 (2) ◽  
pp. 121-133
Author(s):  
Robin Arnall ◽  
Yors Garcia ◽  
Annette K. Griffith ◽  
Jack Spear
Keyword(s):  
Visual Impairment ◽  
Private School ◽  
Sensory Input ◽  
Language Skills ◽  
Autism Spectrum ◽  
Multiple Baseline ◽  
Stimulus Generalization ◽  
Baseline Design ◽  
Tactile Stimuli ◽  
Low Levels

Introduction: The main objective of this study was to determine whether stimulus symmetry, or untaught generalized relations among stimuli, could be demonstrated using audio and tactile stimuli (i.e., nonvisual). Methods: A modified alternating treatment within a concurrent multiple baseline design across nonvisual stimulus sets (i.e., tactile and audio) was implemented with Zach, an 11-year-old male diagnosed with autism and visual impairment, to teach two relations (sound–touch and sound–label) among stimuli. Following training, the researcher tested whether Zach could identify stimuli through an untaught relation (touch–label). The study presented here required a week to complete and was conducted at a private school for individuals with behavioral concerns. Results: During baseline, Zach demonstrated low levels of correct responses (average of 7% across all relations) for all skills. In the training phase (for only two of the three targeted skills, sound–touch and sound–label relations), Zach demonstrated proficiency for most stimuli used in the sets (average of 61% across relations). Finally, in the testing phase (the untaught touch–label relation), Zach demonstrated high levels of generalized acquisition (89%). Discussion: Results indicated that the procedure used in this study could be generalized to novel populations, including those with visual impairments, and that different forms of sensory input could be used, including auditory and tactile-based teaching. Implications for practitioners: Individuals working with learners with differing levels of visual impairment could utilize the demonstrated procedure to associate types of stimuli, using methods other than visual input. The procedure outlined would benefit a population that may require assistance with developing language skills but who also may have difficulties using common visual stimuli.

Segmental differences in pathways between crayfish giant axons and fast flexor motoneurons

1985 ◽  
Vol 53 (1) ◽  
pp. 252-265 ◽  
Author(s):  
L. A. Miller ◽  
G. Hagiwara ◽  
J. J. Wine
Keyword(s):  
High Probability ◽  
Behavior Pattern ◽  
Excitatory Input ◽  
Conclusive Evidence ◽  
Spatial Patterning ◽  
Command Neurons ◽  
Additional Input ◽  
Premotor Neurons ◽  
Escape Trajectories ◽  
Escape Responses

We have used electrophysiological techniques to document segmental differences in the pathways between the giant, escape command axons, lateral giants (LG) and medial giants (MG), and the nongiant, fast flexor (FF) motoneurons. We found no difference in the input from LG and MG axons to FF motoneurons in the posterior (4th and 5th) ganglia. Since flexor motor output in these segments would be inconsistent with the LG-evoked behavior pattern, this finding was puzzling. Electromyographic (EMG) recordings during escape responses by intact unrestrained animals confirm that the FF muscles innervated by the posterior ganglia are not excited during LG-mediated tailflips, but are excited during MG-mediated tailflips. In the 2nd and 3rd ganglia, the command axons fire the FF motoneurons with high probability, in part via electrical excitatory postsynaptic potentials (EPSPs) from premotor neurons, the segmental giants (SG). In the 4th and 5th ganglia, the equivalent pathway is much less effective. Single, directly elicited impulses in SGs in ganglia 2 and 3 fire their respective FF motoneurons with high probability, while those in ganglia 4 and 5 rarely fire FF motoneurons. The command axons fire the SGs reliably in all segments. The amplitude of the SG-evoked EPSP in FF motoneurons is significantly smaller in posterior vs. anterior ganglia. For technical reasons, we are unable to present conclusive evidence on ganglionic variations in FF-motoneuron thresholds. The FF motoneurons receive additional excitatory input from intersegmental interneurons recruited by the command neurons. Motoneurons in ganglia 4 and 5 are excited by large interneurons that do not synapse on motoneurons in ganglia 2 and 3, but this additional input is not sufficient to compensate for the weaker effect of SG input. Unlike the all-or-none segmental differences demonstrated previously for the LG-to-motor giant pathway (24), the SG-to-FF pathway changes gradually, retains significant though subthreshold strength in posterior ganglia, and is common to both LGs and MGs. These features provide opportunities for variation in the spatial patterning of flexion and in the resulting escape trajectories.

scholarly journals Pregnancy-related changes in connections from the cervix to forebrain and hypothalamus in mice

Reproduction ◽  
2010 ◽  
Vol 140 (1) ◽  
pp. 155-164 ◽  
Author(s):  
Steven M Yellon ◽  
Lauren A Grisham ◽  
Genevieve M Rambau ◽  
Thomas J Lechuga ◽  
Michael A Kirby
Keyword(s):  
Image Analysis ◽  
Motor Cortex ◽  
Paraventricular Nucleus ◽  
Sensory Input ◽  
Pseudorabies Virus ◽  
Brain Regions ◽  
Autonomic Functions ◽  
Effector Functions ◽  
Periventricular Nucleus ◽  
Pregnant Mice

The transneuronal tracer pseudorabies virus was used to test the hypothesis that connections from the cervix to the forebrain and hypothalamus are maintained with pregnancy. The virus was injected into the cervix of nonpregnant or pregnant mice, and, after 5 days, virus-labeled cells and fibers were found in specific forebrain regions and, most prominently, in portions of the hypothalamic paraventricular nucleus. With pregnancy, fewer neurons and fibers were evident in most brain regions compared to that in nonpregnant mice. In particular, little or no virus was found in the medial and ventral parvocellular subdivisions, anteroventral periventricular nucleus, or motor cortex in pregnant mice. By contrast, labeling of virus was sustained in the dorsal hypothalamus and suprachiasmatic nucleus in all groups. Based upon image analysis of digitized photomicrographs, the area with label in the rostral and medial parvocellular paraventricular nucleus and magnocellular subdivisions was significantly reduced in mice whose cervix was injected with virus during pregnancy than in nonpregnant mice. The findings indicate that connections from the cervix to brain regions that are involved in sensory input and integrative autonomic functions are reduced during pregnancy. The findings raise the possibility that remaining pathways from the cervix to the forebrain and hypothalamus may be important for control of pituitary neuroendocrine secretion, as well as for effector functions in the cervix as pregnancy nears term.

Preparing for the unpredictable: adaptive feedback enhances the response to unexpected communication signals

2012 ◽  
Vol 107 (4) ◽  
pp. 1241-1246 ◽  
Author(s):  
Gary Marsat ◽  
Leonard Maler
Keyword(s):  
Nervous System ◽  
Sensory Input ◽  
Low Frequency ◽  
Excitatory Input ◽  
Negative Image ◽  
Communication Signals ◽  
First Order ◽  
Communication Signal ◽  
Apical Dendrites ◽  
Spike Bursts

To interact with the environment efficiently, the nervous system must generate expectations about redundant sensory signals and detect unexpected ones. Neural circuits can, for example, compare a prediction of the sensory signal that was generated by the nervous system with the incoming sensory input, to generate a response selective to novel stimuli. In the first-order electrosensory neurons of a gymnotiform electric fish, a negative image of low-frequency redundant communication signals is subtracted from the neural response via feedback, allowing unpredictable signals to be extracted. Here we show that the cancelling feedback not only suppresses the predictable signal but also actively enhances the response to the unpredictable communication signal. A transient mismatch between the predictive feedback and incoming sensory input causes both to be positive: the soma is suddenly depolarized by the unpredictable input, whereas the neuron's apical dendrites remain depolarized by the lagging cancelling feedback. The apical dendrites allow the backpropagation of somatic spikes. We show that backpropagation is enhanced when the dendrites are depolarized, causing the unpredictable excitatory input to evoke spike bursts. As a consequence, the feedback driven by a predictable low-frequency signal not only suppresses the response to a redundant stimulus but also induces a bursting response triggered by unpredictable communication signals.

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