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Philosophical Transactions of the Royal... Apr 2017The ability to stop ongoing movement is fundamental to animal survival. Behavioural arrest involves the hierarchical integration of information throughout the forebrain,... (Review)
Review
The ability to stop ongoing movement is fundamental to animal survival. Behavioural arrest involves the hierarchical integration of information throughout the forebrain, which ultimately leads to the coordinated inhibition and activation of specific brainstem motor centres. Recent advances have shed light on multiple regions and pathways involved in this critical behavioural process. Here, we synthesize these new findings together with previous work to build a more complete understanding of the circuit mechanisms underlying suppression of ongoing action. We focus on three specific conditions leading to behavioural arrest: goal completion, fear and startle. We outline the circuitry responsible for the production of these behaviours and discuss their dysfunction in neurological disease.This article is part of the themed issue 'Movement suppression: brain mechanisms for stopping and stillness'.
Topics: Animals; Fear; Goals; Humans; Inhibition, Psychological; Movement; Nervous System Diseases; Neural Pathways; Reflex, Startle
PubMed: 28242731
DOI: 10.1098/rstb.2016.0197 -
Otolaryngologic Clinics of North America Aug 2020Animal models have significantly contributed to understanding the pathophysiology of chronic subjective tinnitus. They are useful because they control etiology, which in... (Review)
Review
Animal models have significantly contributed to understanding the pathophysiology of chronic subjective tinnitus. They are useful because they control etiology, which in humans is heterogeneous; employ random group assignment; and often use methods not permissible in human studies. Animal models can be broadly categorized as either operant or reflexive, based on methodology. Operant methods use variants of established psychophysical procedures to reveal what an animal hears. Reflexive methods do the same using elicited behavior, for example, the acoustic startle reflex. All methods contrast the absence of sound and presence of sound, because tinnitus cannot by definition be perceived as silence.
Topics: Acoustic Stimulation; Animals; Behavior, Animal; Disease Models, Animal; Hearing; Hearing Loss; Humans; Reflex; Reflex, Startle; Reproducibility of Results; Sound; Tinnitus
PubMed: 32327193
DOI: 10.1016/j.otc.2020.03.001 -
Psychophysiology Jun 2017This research examined human defensive reactivity when exposure to an aversive event could be escaped but not entirely avoided. Prolonged visual cues indicated whether...
This research examined human defensive reactivity when exposure to an aversive event could be escaped but not entirely avoided. Prolonged visual cues indicated whether exposure to an upcoming aversive (i.e., disgusting) picture could be terminated after onset (escaped) or not, or that a neutral go signal would appear. Acoustically elicited startle reflexes were measured during each cue interval, as were cardiac and skin conductance activity. Early in the cuing interval, startle reflexes were potentiated during both escape and inescapable exposure trials, compared to the simple motor context. Later in the interval, reflexes remained potentiated for both escapable and inescapable trials, with potentiation further enhanced when aversive exposure could not be escaped compared to when exposure could be escaped. Heart rate deceleration in the cuing interval indicated increased vigilance when preparing any (escape or neutral) action, whereas skin conductance responding indicated enhanced sympathetic action mobilization particularly in an escape context. These data suggest that startle reflexes engaged in an escape context reflect both motor-related response inhibition and aversive potentiation, and they indicate that defensive motivation is engaged whenever aversive exposure is guaranteed, regardless of whether it can be escaped or not.
Topics: Adolescent; Arousal; Autonomic Nervous System; Blood Pressure; Emotions; Escape Reaction; Fear; Female; Galvanic Skin Response; Heart Rate; Humans; Male; Reflex, Startle; Young Adult
PubMed: 28218794
DOI: 10.1111/psyp.12842 -
International Journal of... May 2017Startle reflex and affect-modified startle reflex are used as indicators of defensive reactivity and emotional processing, respectively. The present study investigated...
Startle reflex and affect-modified startle reflex are used as indicators of defensive reactivity and emotional processing, respectively. The present study investigated the heritability of both the startle blink reflex and affect modification of this reflex in a community sample of 772 twins ages 14-15years old. Subjects were shown affective picture slides falling in three valence categories: negative, positive and neutral; crossed with two arousal categories: high arousal and low arousal. Some of these slides were accompanied with a loud startling noise. Results suggested sex differences in mean levels of startle reflex as well as in proportions of variance explained by genetic and environmental factors. Females had higher mean startle blink amplitudes for each valence-arousal slide category, indicating greater baseline defensive reactivity compared to males. Startle blink reflex in males was significantly heritable (49%), whereas in females, variance was explained primarily by shared environmental factors (53%) and non-shared environmental factors (41%). Heritability of affect modified startle (AMS) was found to be negligible in both males and females. These results suggest sex differences in the etiology of startle reactivity, while questioning the utility of the startle paradigm for understanding the genetic basis of emotional processing.
Topics: Acoustic Stimulation; Adolescent; Analysis of Variance; Arousal; Blinking; Child; Electromyography; Environment; Female; Humans; Male; Models, Genetic; Photic Stimulation; Reflex, Startle; Sex Characteristics; Twins, Dizygotic; Twins, Monozygotic
PubMed: 27666795
DOI: 10.1016/j.ijpsycho.2016.09.009 -
Biological Psychiatry. Cognitive... Jan 2018The National Institute of Mental Health's Research Domain Criteria initiative is a research framework designed toward understanding psychopathology as abnormalities of... (Review)
Review
The National Institute of Mental Health's Research Domain Criteria initiative is a research framework designed toward understanding psychopathology as abnormalities of dimensional neurobehavioral constructs rather than in terms of DSM-defined categories. Research Domain Criteria constructs within the negative valence domain are particularly relevant for understanding anxiety and depressive disorders, which are pervasive, debilitating, and characterized by negative processing bias. One important direction for Research Domain Criteria research is investigating processes and parameters related to the time course (or chronometry) of negative valenced constructs. Two reliable methods for assessing chronometry are event-related potentials (ERPs) and startle blink. In this qualitative review, we examine ERP and startle studies of individuals with anxiety or depression or individuals vulnerable to affective disorders. The aim of the review is to highlight how these methods can inform the role of chronometry in the spectrum of anxiety and depression. ERP studies examining different chronometry facets of negative valenced responses have shown that transdiagnostic groups of individuals with internalizing psychopathologies exhibit abnormalities at early stages of processing. Startle reactivity studies have robustly differentiated fear-based disorders (e.g., panic disorder, social phobia) from other anxiety disorders (e.g., generalized anxiety disorder) and have also shown that different internalizing phenotypes exhibit different patterns of habituation. Findings lend support to the value of ERP and startle measures in identifying groups that cut across conventional classification systems. We also highlight methodological issues that can aid in the validity and reproducibility of ERP and startle findings and, ultimately, in the goal of developing more precise models of anxiety and depression.
Topics: Affect; Anxiety Disorders; Blinking; Brain; Depressive Disorder; Electroencephalography; Electromyography; Evoked Potentials; Humans; Reflex, Startle; Time Factors
PubMed: 29397073
DOI: 10.1016/j.bpsc.2017.09.004 -
Hearing Research Feb 2022The primary startle response (SR) is an innate reaction evoked by sudden and intense acoustic, tactile or visual stimuli. In rodents and humans the SR involves reflexive...
The primary startle response (SR) is an innate reaction evoked by sudden and intense acoustic, tactile or visual stimuli. In rodents and humans the SR involves reflexive contractions of the face, neck and limb muscles. The acoustic startle response (ASR) pathway consists of auditory nerve fibers (AN), cochlear root neurons (CRNs) and giant neurons of the caudal pontine reticular nucleus (PnC), which synapse on cranial and spinal motor neurons. The tactile startle response (TSR) is transmitted by primary sensory neurons to the principal sensory (Pr5) and spinal (Sp5) trigeminal nuclei. The ventral part of Pr5 projects directly to the PnC neurons. The SR requires rapid transmission of sensory information to initiate a fast motor response. Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPAR) are necessary to transmit auditory information to the PnC neurons and elicit the SR. AMPARs containing the glutamate AMPAR subunit 4 (GluA4) have fast kinetics, which makes them ideal candidates to transmit the SR signal. This study examined the role of GluA4 within the primary SR pathway by using GluA4 knockout (GluA4-KO) mice. Deletion of GluA4 considerably decreased the amplitude and probability of successful ASR and TSR, indicating that the presence of this subunit is critical at a common station within the startle pathway. We conclude that deletion of GluA4 affects the transmission of sensory signals from acoustic and tactile pathways to the motor component of the startle reflex. Therefore, GluA4 is required for the full response and for reliable elicitation of the startle response.
Topics: Acoustic Stimulation; Acoustics; Animals; Mice; Neurons; Reflex, Startle; Synapses
PubMed: 34915397
DOI: 10.1016/j.heares.2021.108410 -
Journal of the Association For Research... Apr 2022Cross-modal plasticity occurs when the function of remaining senses is enhanced following deprivation or loss of a sensory modality. Auditory neural responses are...
Cross-modal plasticity occurs when the function of remaining senses is enhanced following deprivation or loss of a sensory modality. Auditory neural responses are enhanced in the auditory cortex, including increased sensitivity and frequency selectivity, following short-term visual deprivation in adult mice (Petrus et al. Neuron 81:664-673, 2014). Whether or not these visual deprivation-induced neural changes translate into improved auditory perception and performance remains unclear. As an initial investigation of the effects of adult visual deprivation on auditory behaviors, CBA/CaJ mice underwent binocular enucleation at 3-4 weeks old and were tested on a battery of learned behavioral tasks, acoustic startle response (ASR), and prepulse inhibition (PPI) tests beginning at least 2 weeks after the enucleation procedure. Auditory brain stem responses (ABRs) were also measured to screen for potential effects of visual deprivation on non-behavioral hearing function. Control and enucleated mice showed similar tone detection sensitivity and frequency discrimination in a conditioned lick suppression test. Both groups showed normal reactivity to sound as measured by ASR in a quiet background. However, when startle-eliciting stimuli were presented in noise, enucleated mice showed decreased ASR amplitude relative to controls. Control and enucleated mice displayed no significant differences in ASR habituation, PPI tests, or ABR thresholds, or wave morphology. Our findings suggest that while adult-onset visual deprivation induces cross-modal plasticity at the synaptic and circuit levels, it does not substantially influence simple auditory behavioral performance.
Topics: Acoustic Stimulation; Animals; Evoked Potentials, Auditory, Brain Stem; Hearing; Mice; Mice, Inbred CBA; Reflex, Startle
PubMed: 35084628
DOI: 10.1007/s10162-022-00835-5 -
The Journal of Experimental Biology Mar 2020The acoustic startle reflex is an oligo-synaptic reflex arc elicited by rapid-onset sounds. Odontocetes evolved a range of specific auditory adaptations to aquatic...
The acoustic startle reflex is an oligo-synaptic reflex arc elicited by rapid-onset sounds. Odontocetes evolved a range of specific auditory adaptations to aquatic hearing and echolocation, e.g. the ability to downregulate their auditory sensitivity when emitting clicks. However, it remains unclear whether these adaptations also led to changes of the startle reflex. We investigated reactions to startling sounds in two bottlenose dolphins () and one false killer whale (). Animals were exposed to 50 ms, 1/3 octave band noise pulses of varying levels at frequencies of 1, 10, 25 and 32 kHz while positioned in a hoop station. Startle responses were quantified by measuring rapid muscle contractions using a three-dimensional accelerometer attached to the dolphin. Startle magnitude increased exponentially with increasing received levels. Startle thresholds were frequency dependent and ranged from 131 dB at 32 kHz to 153 dB at 1 kHz (re. 1 µPa). Startle thresholds only exceeded masked auditory AEP thresholds of the animals by 47 dB but were ∼82 dB above published behavioural audiograms for these species. We also tested the effect of stimulus rise time on startle magnitude using a broadband noise pulse. Startle responses decreased with increasing rise times from 2 to 100 ms. Models suggested that rise times of 141-220 ms were necessary to completely mitigate startle responses. Our data showed that the startle reflex is conserved in odontocetes and follows similar principles as in terrestrial mammals. These principles should be considered when assessing and mitigating the effects of anthropogenic noise on marine mammals.
Topics: Acoustic Stimulation; Animals; Auditory Threshold; Bottle-Nosed Dolphin; Dolphins; Echolocation; Female; Hawaii; Male; Reflex, Startle
PubMed: 32165452
DOI: 10.1242/jeb.208470 -
Acta Psychologica Oct 2021The startle reflex has been suggested to operate as a psychophysiological marker of psychopathic personality, based on findings from studies using a range of different... (Review)
Review
The startle reflex has been suggested to operate as a psychophysiological marker of psychopathic personality, based on findings from studies using a range of different methodologies and participant samples. The present review aims at synthesizing existing evidence of the relationship between psychopathy and the startle reflex across task paradigms, psychopathic personality subtypes and subdimensions, participant samples (i.e., incarcerated/ clinical or non-offenders), and age groups using the triarchic model of psychopathy as a frame of reference. Systematic literature searches were conducted up until the 24th of March 2020 in PubMed, PsycINFO, and Web of Science. A total of 2311 potential studies were identified, out of which 40 met relevancy and quality criteria. Results indicate that reduced aversive startle potentiation is associated with psychopathic personality in general, but clusters of traits relating to the triarchic model constructs of boldness and meanness in particular. Available evidence suggest that startle paradigms could be meaningful for differentiating individuals with and without psychopathic personality. Findings support suggestions of psychopathic personality as a multifaceted, rather than a unitary construct. Reduced aversive startle potentiation has also been found in relation to psychopathic features in child-aged samples but work of this kind is limited and more research is needed. Future studies should focus on greater consistency in task paradigms and analytic strategies to enhance the capacity to compare and integrate findings across studies.
Topics: Adolescent; Affect; Aged; Antisocial Personality Disorder; Child; Humans; Reflex, Startle; Young Adult
PubMed: 34628215
DOI: 10.1016/j.actpsy.2021.103427 -
Eye (London, England) Jan 2022
Topics: Humans; Ophthalmology; Postoperative Complications; Reflex, Startle; Surgeons
PubMed: 34326498
DOI: 10.1038/s41433-021-01703-x