scholarly journals Peripheral injury induces long-term sensitization of defensive responses to visual and tactile stimuli in the squid Loligo pealeii, Lesueur 1821

2011 ◽  
Vol 214 (19) ◽  
pp. 3173-3185 ◽  
Author(s):  
R. J. Crook ◽  
T. Lewis ◽  
R. T. Hanlon ◽  
E. T. Walters
Keyword(s):  
Defensive Responses ◽  
Tactile Stimuli ◽  
Peripheral Injury ◽  
Loligo Pealeii

Evidence That Long-Term Hyperexcitability of the Sensory Neuron Soma Induced by Nerve Injury in Aplysia Is Adaptive

2005 ◽  
Vol 94 (3) ◽  
pp. 2218-2230 ◽  
Author(s):  
Xavier Gasull ◽  
Xiaogang Liao ◽  
Michael F. Dulin ◽  
Cynthia Phelps ◽  
Edgar T. Walters
Keyword(s):  
Sensory Neuron ◽  
Sensory Input ◽  
Aplysia Californica ◽  
Afferent Pathway ◽  
Sensory Deficits ◽  
Diverse Species ◽  
Peripheral Injury ◽  
Adaptive Consequences ◽  
Neuron Soma

Peripheral axotomy induces long-term hyperexcitability (LTH) of centrally located sensory neuron (SN) somata in diverse species. In mammals this LTH can promote spontaneous activity of pain-related SNs, and such activity may contribute to neuropathic pain and hyperalgesia. However, few axotomized SN somata begin to fire spontaneously in any species, and why so many SNs display soma LTH after axotomy remains a mystery. Is soma LTH a side effect of injury with pathological but no adaptive consequences, or was this response selected during evolution for particular functions? A hypothesis for one function of soma LTH in nociceptive SNs in Aplysia californica is proposed: after peripheral injury that produces partial axotomy of some SNs, compensation for sensory deficits and protective sensitization are achieved by facilitating afterdischarge near the soma, which amplifies sensory input from injured peripheral fields. Four predictions of this hypothesis were confirmed in SNs that innervate the tail. First, LTH of SN somata was induced by a relatively natural axotomizing event—a small cut across part of the tail in the absence of anesthesia. Second, soma LTH was selectively expressed in SNs having axons in cut or crushed nerves rather than nearby, uninjured nerves. Third, after several weeks soma LTH began to reverse when functional recovery of the interrupted afferent pathway was shown by reestablishment of a centrally mediated siphon reflex. Fourth, axotomized SNs developed central afterdischarge that amplified sensory discharge coming from the periphery, and the afterdepolarization underlying this afterdischarge was enhanced by previous axotomy.

Patterns of Perceptual-Motor Dysfunction in Children: A Factor Analytic Study

1965 ◽  
Vol 20 (2) ◽  
pp. 335-368 ◽  
Author(s):  
A. Jean Ayres
Keyword(s):  
Motor Planning ◽  
Tactile Perception ◽  
The Body ◽  
Motor Dysfunction ◽  
Defensive Responses ◽  
Tactile Defensiveness ◽  
Factor Analytic Study ◽  
Tactile Stimuli ◽  
Developmental Apraxia ◽  
Two Sides

Analysis of test scores made by 100 children with and 50 without suspected perceptual deficits lead to hypothesizing five syndromes characteristic of dysfunction: (a) developmental apraxia, distinguished by deficits in motor planning, tactile perception and finger identification; (b) tactile, kinesthetic and visual perceptual dysfunction in form and position in space; (c) tactile defensiveness, demonstrated by hyperactive-distractible behavior, faulty tactile perception and defensive responses to tactile stimuli; (d) deficit of integration of the two sides of the body, identified by difficulty in right-left discrimination, avoidance in crossing the mid-line, and incoordinate bilateral hand movements; (e) deficit of visual figure-ground discrimination.

scholarly journals Psychogenic Dystonia: a Review of 18 Cases

1995 ◽  
Vol 22 (2) ◽  
pp. 136-143 ◽  
Author(s):  
Anthony E. Lang
Keyword(s):  
Clinical Characteristics ◽  
Adult Life ◽  
Retrospective Chart Review ◽  
Abnormal Movements ◽  
Peripheral Injury ◽  
Psychogenic Movement Disorders ◽  
Long Term Follow Up ◽  
Paroxysmal Dystonia

AbstractObjective:To review the clinical characteristics and associated features found in patients with psychogenic dystonia.Methods:A 10 year retrospective chart review of all patients diagnosed by the author as having psychogenic dystonia.Results:Eighteen patients fulfilled diagnostic criteria for “Documented” or “Clinically Established” psychogenic dystonia. Clinical characteristics of the dystonia were inconsistent or incongruous with established forms of organic dystonia. Fourteen of the 18 patients had a known precipitant. In most, the onset was abrupt and progression occurred rapidly, often to fixed dystonic postures. In contrast to idiopathic dystonia, involvement of the legs was common (12 patients), despite onset in adult life. Although cases of isolated paroxysmal dystonia were excluded in the review, 10 patients had paroxysmal worsening of dystonia or other abnormal movements. Pain was a prominent feature in 14 of 16 patients with the complaint and 1 patient with documented psychogenic dystonia also had well established reflex sympathetic dystrophy (RSD). Other psychogenic movement disorders, psychogenic neurological signs and multiple somatizations were common. Long-term follow up was available for less than one-half of the patients. Outcome varied considerably; some patients had complete resolution of symptoms (including 1 who had undergone 2 previous thalamotomies) and others remained disabled by persistent dystonia.Conclusions:Dystonia is uncommonly due to primary psychological factors. At times this is an extremely difficult diagnosis to make and even when the diagnosis is confirmed, management remains very challenging. Future studies are required in hopes of providing more efficient means of distinguishing psychogenic dystonia from other dystonic syndromes especially those which rarely follow peripheral injury or accompany RSD/causalgia syndromes.

Memory and habituation to harmful and non-harmful stimuli in a field population of the sensitive plant, Mimosa pudica

2021 ◽  
pp. 1-10
Author(s):  
Ella Serpell ◽  
Johel Chaves-Campos
Keyword(s):  
Leaf Damage ◽  
Wild Plants ◽  
Long Term Memory ◽  
Mimosa Pudica ◽  
Simulated Herbivory ◽  
Herbivore Damage ◽  
Term Memory ◽  
Tactile Stimuli ◽  
Light Stimuli

Abstract Mimosa pudica is a Neotropical legume that closes its leaves rapidly in response to touch stimulation, hypothetically as herbivory defence. Habituation to non-harmful stimuli and long-term memory of past events have been demonstrated in this species, the former with relatively heavy objects and the latter under laboratory conditions. This species should not habituate to harmful stimuli if leaf movement is a response to herbivore damage. We tested in Monteverde, Costa Rica, whether (1) memory occurs in wild plants, (2) whether habituation occurs under harmful stimuli: simulated herbivory, and (3) whether wild plants can habituate to light non-harmful stimuli. The degree of closing of the leaflets and time until reopening was measured in response to repeated harmful and non-harmful stimuli. The results showed habituation to repeated non-harmful very light stimuli and showed lack of habituation to simulated leaf damage. Wild plants also showed faster rehabituation to repeated non-harmful stimuli when they had been exposed 15 days previously, suggesting possible long-term memory. These results indicate that wild plants are capable of (1) distinguishing between harmful and non-harmful stimuli (only habituating to the latter), (2) memorizing previous events, and 3) habituating very light tactile stimuli commonly experienced in the field.

scholarly journals Long-Term Use of a Sensory Prosthesis Improves Function in a Patient With Peripheral Neuropathy: A Case Report

2021 ◽  
Vol 12 ◽  
Author(s):  
Diane M. Wrisley ◽  
Gillian McLean ◽  
Jennifer Baity Hill ◽  
Lars I. E. Oddsson
Keyword(s):  
Case Report ◽  
Peripheral Neuropathy ◽  
Metatarsophalangeal Joint ◽  
Type Ii Diabetes Mellitus ◽  
Sensory Function ◽  
Sensory Substitution ◽  
Similar Response ◽  
Tactile Stimuli ◽  
History Of

Background: Peripheral neuropathy (PN) can result in either partial or complete loss of distal sensation resulting in an increased fall risk. Walkasins® uses a shoe insert to detect the magnitude and direction of sway and sends signals to a leg unit that provides sensory balance cues. The objective of this case report is to describe the long-term influence of the Walkasins® lower limb sensory neuroprosthesis on balance and gait for an individual with diabetic PN.Case Description: A 51-year-old male with a 3-year history of PN and a 10-year history of type II diabetes mellitus was fitted bilaterally with Walkasins® and utilized them 8–10 hours/day for more than 2 years. Although, vibration and tactile sensation thresholds were severely impaired at his 1st metatarsophalangeal joint and the lateral malleolus bilaterally he could perceive tactile stimuli from the Walkasins® above the ankles.Outcomes: Following Walkasins® use, his Activities-specific Balance Confidence Scale (ABC) scores improved from 33 to 80%. His mean Vestibular Activities of Daily Living (VADL) scores decreased from 3.54 to 1. His Functional Gait Assessment (FGA) scores increased from 13/30 to 28/30 and his miniBESTest scores improved from 15/28 to 26/28. Gait speed increased from 0.23 to 1.5 m/s. The patient described a decrease in pain and cramping throughout his lower extremities and an increase in function.Discussion: Gait and balance improved with the use of the Walkasins® and participation in a wellness program. This improvement suggests that the use of sensory substitution devices, such as the Walkasins®, may replace sensory deficits related to gait and balance dysfunction experienced by patients with PN. Further research is needed to determine if other patients will have a similar response and what the necessary threshold of sensory function is to benefit from use of the Walkasins®.

scholarly journals Serotonergic control in initiating defensive responses to unexpected tactile stimuli in the trap-jaw ant Odontomachus kuroiwae

2020 ◽  
Vol 223 (19) ◽  
pp. jeb228874 ◽  
Author(s):  
Hitoshi Aonuma
Keyword(s):  
Oral Administration ◽  
Defensive Behavior ◽  
Tactile Stimulation ◽  
Defensive Response ◽  
Potential Threat ◽  
Defensive Responses ◽  
Tactile Stimuli ◽  
Neuronal Mechanisms ◽  
The Brain ◽  
Unexpected Stimulus

ABSTRACTThe decision to express either a defensive response or an escape response to a potential threat is crucial for insects to survive. This study investigated an aminergic mechanism underlying defensive responses to unexpected touch in an ant that has powerful mandibles, the so-called trap-jaw. The mandibles close extremely quickly and are used as a weapon during hunting. Tactile stimulation to the abdomen elicited quick forward movements in a dart escape in 90% of the ants in a colony. Less than 10% of the ants responded with a quick defensive turn towards the source of stimulation. To reveal the neuronal mechanisms underlying this defensive behavior, the effect of brain biogenic amines on the responses to tactile stimuli were investigated. The levels of octopamine (OA), dopamine (DA) and serotonin (5HT) in the brain were significantly elevated in ants that responded with a defensive turn to the unexpected stimulus compared with ants that responded with a dart escape. Oral administration of DA and 5HT demonstrated that both amines contributed to the initiation of a defensive response. Oral administration of l-DOPA weakly affected the initiation of the defensive turn, while 5-hydroxy-l-tryptophan (5HTP) strongly affected the initiation of defensive behavior. Oral administration of ketanserin, a 5HT antagonist, inhibited the initiation of the defensive turn in aggressive workers, abolishing the effects of both 5HT and 5HTP on the initiation of turn responses. These results indicate that 5HTergic control in the nervous system is a key for the initiation of defensive behavior in the trap-jaw ant.

scholarly journals De novo protein synthesis in distinct centrolateral amygdala interneurons is required for associative emotional memories

2020 ◽  
Author(s):  
Prerana Shrestha ◽  
Zhe Shan ◽  
Maggie Marmarcz ◽  
Karen San Agustin Ruiz ◽  
Adam Taye Zerihoun ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Basolateral Amygdala ◽  
De Novo ◽  
Brain Area ◽  
Dynamic Environment ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor ◽  
Defensive Responses ◽  
De Novo Protein Synthesis

To survive in a dynamic environment, animals need to identify and appropriately respond to stimuli that signal danger1,2. At the same time, animal survival also depends on suppressing the threat response during a stimulus that predicts absence of threat, i.e. safety3-5. Understanding the biological substrates of differential threat memories in which animals learn to flexibly switch between expressing and suppressing defensive responses to a threat-predictive cue and a safety cue, respectively, is critical for developing treatments for memory disorders such as PTSD6. A key brain area for processing and storing threat memories is the centrolateral amygdala (CeL), which receives convergent sensory inputs from the parabrachial nucleus and the basolateral amygdala and connects directly to the output nucleus of amygdala, the centromedial nucleus, to mediate defensive responses7-9. Despite a plethora of studies on the importance of neuronal activity in specific CeL neuronal populations during memory acquisition and retrieval10-12, little is known about regulation of their protein synthesis machinery. Consolidation of long-term, but not short-term, threat memories requires de novo protein synthesis, which suggests that the translation machinery in CeL interneurons is tightly regulated in order to stabilize associative memories. Herein, we have applied intersectional chemogenetic strategies in CeL interneurons to block cell type-specific translation initiation programs that are sensitive to depletion of eukaryotic initiation factor 4E (eIF4E) and phosphorylation of eukaryotic initiation factor 2α (p-eIF2α), respectively. We show that in a differential threat conditioning paradigm, de novo translation in somatostatin-expressing (SOM) interneurons in the CeL is necessary for long-term storage of conditioned threat response whereas de novo translation in protein kinase Cδ-expressing (PKCδ) interneurons in the CeL is essential for storing conditioned response inhibition to a safety cue. Further, we show that oxytocinergic neuromodulation of PKCδ interneurons during differential threat learning is important for long-lasting cued threat discrimination. Our results indicate that the molecular elements of a differential threat memory trace are compartmentalized in distinct CeL interneuron populations and provide new mechanistic insight into the role of de novo protein synthesis in consolidation of long-term memories.

scholarly journals Serotonergic control in initiating defensive responses to unexpected tactile stimuli in the trap-jaw ant Odontomachus kuroiwae

2020 ◽  
Author(s):  
Hitoshi Aonuma
Keyword(s):  
Oral Administration ◽  
Defensive Behavior ◽  
Control Mechanisms ◽  
Defensive Response ◽  
Potential Threat ◽  
Defensive Responses ◽  
Neuronal Control ◽  
Tactile Stimuli ◽  
The Brain ◽  
Unexpected Stimulus

ABSTRACTA decision to express a defensive response or an escape response to a potential threat is crucial for insects to survive. This study investigated an aminergic mechanism underlying defensive responses to unexpected touch in an ant that has powerful mandibles, the so-called trap-jaw. The mandibles close extremely quickly and are used as a weapon during hunting. Tactile stimulation to the abdomen elicited quick forward movements in a “dart escape” in 90% of the ants in a colony. Less than 10% of the ants responded with a quick “defensive turn” towards the source of stimulation. To reveal the neuronal control mechanisms underlying this defensive behavior, the effects of brain biogenic amines on the responses to tactile stimulus were investigated. The levels of octopamine (OA), dopamine (DA) and serotonin (5HT) in the brain were significantly elevated in ants that responded with a defensive turn to the unexpected stimulus compared to ants that responded with a dart escape. Oral administration of DA and 5HT demonstrated that both amines contributed to the initiation of a defensive response to the stimulus. Oral administration of L-DOPA weakly affected the initiation of the defensive turn, while 5HTP strongly affected the initiation of defensive behavior. Oral administration of an antagonist of 5HT, ketanserin, abolished the effect of 5HTP. These results indicate that endogenous 5HT in the brain has a key role to play in modulating the initiation of defensive behavior in the trap-jaw ant.

scholarly journals Interhemispheric plasticity is mediated by maximal potentiation of callosal inputs

2019 ◽  
Vol 116 (13) ◽  
pp. 6391-6396 ◽  
Author(s):  
Emily Petrus ◽  
Galit Saar ◽  
Zhiwei Ma ◽  
Steve Dodd ◽  
John T. R. Isaac ◽  
...  
Keyword(s):  
Barrel Cortex ◽  
Long Term Potentiation ◽  
Blood Oxygen Level Dependent ◽  
Cortical Reorganization ◽  
Blood Oxygen Level ◽  
Peripheral Injury ◽  
Term Potentiation ◽  
A Cell ◽  
Striking Change

Central or peripheral injury causes reorganization of the brain’s connections and functions. A striking change observed after unilateral stroke or amputation is a recruitment of bilateral cortical responses to sensation or movement of the unaffected peripheral area. The mechanisms underlying this phenomenon are described in a mouse model of unilateral whisker deprivation. Stimulation of intact whiskers yields a bilateral blood-oxygen-level−dependent fMRI response in somatosensory barrel cortex. Whole-cell electrophysiology demonstrated that the intact barrel cortex selectively strengthens callosal synapses to layer 5 neurons in the deprived cortex. These synapses have larger AMPA receptor- and NMDA receptor-mediated events. These factors contribute to a maximally potentiated callosal synapse. This potentiation occludes long-term potentiation, which could be rescued, to some extent, with prior long-term depression induction. Excitability and excitation/inhibition balance were altered in a manner consistent with cell-specific callosal changes and support a shift in the overall state of the cortex. This is a demonstration of a cell-specific, synaptic mechanism underlying interhemispheric cortical reorganization.

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