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Acta Paediatrica (Oslo, Norway : 1992) Nov 2023We discuss the aetiology of recurrent abdominal pain of non-organic origin, according to the Rome Criteria for Functional Gastrointestinal Disorders and a psychogenic... (Review)
Review
We discuss the aetiology of recurrent abdominal pain of non-organic origin, according to the Rome Criteria for Functional Gastrointestinal Disorders and a psychogenic hypothesis. Stress activates the brain-gut axis, which is important for local gut symptoms, such as abdominal pain, but it also causes pain in other areas, including the head, back and chest. Our research has indicated that the startle reflex plays a dominant role in this stress-induced pain pattern, which is manifested in the whole body. Localised abdominal pain can be part of a general negative stress reaction that causes multiple pains in other areas of the body.
PubMed: 37565357
DOI: 10.1111/apa.16946 -
Neurological Sciences : Official... Oct 2021Startle, a basic alerting reaction common to all mammals, is described as a sudden involuntary movement of the body evoked by all kinds of sudden and unexpected... (Review)
Review
Startle, a basic alerting reaction common to all mammals, is described as a sudden involuntary movement of the body evoked by all kinds of sudden and unexpected stimulus. Startle syndromes are heterogeneous groups of disorders with abnormal and exaggerated responses to startling events, including hyperekplexia, stimulus-induced disorders, and neuropsychiatric startle syndromes. Hyperekplexia can be attributed to a genetic, idiopathic, or symptomatic cause. Excluding secondary factors, hereditary hyperekplexia, a rare neurogenetic disorder with highly genetic heterogeneity, is characterized by neonatal hypertonia, exaggerated startle response provoked by the sudden external stimuli, and followed by a short period of general stiffness. It mainly arises from defects of inhibitory glycinergic neurotransmission. GLRA1 is the major pathogenic gene of hereditary hyperekplexia, along with many other genes involved in the function of glycinergic inhibitory synapses. While about 40% of patients remain negative genetic findings. Clonazepam, which can specifically upgrade the GABARA1 chloride channels, is the main and most effective administration for hereditary hyperekplexia patients. In this review, with the aim at enhancing the recognition and prompting potential treatment for hyperekplexia, we focused on discussing the advances in hereditary hyperekplexia genetics and the expound progress in pathogenic mechanisms of the glycinergic-synapse-related pathway and then followed by a brief overview of other common startle syndromes.
Topics: Animals; Humans; Hyperekplexia; Infant, Newborn; Muscle Rigidity; Receptors, Glycine; Reflex, Startle; Stiff-Person Syndrome
PubMed: 34379238
DOI: 10.1007/s10072-021-05493-8 -
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 -
RotaRod and acoustic startle reflex performance of two potential mouse models for Meniere's disease.The European Journal of Neuroscience Aug 2023Meniere's disease (MD) is a disorder of the inner ear characterized by chronic episodes of vertigo, tinnitus, increased aural pressure, and sensorineural hearing loss....
Meniere's disease (MD) is a disorder of the inner ear characterized by chronic episodes of vertigo, tinnitus, increased aural pressure, and sensorineural hearing loss. Causes of MD are unknown, but endolymphatic hydrops is a hallmark. In addition, 5%-15% of MD cases have been identified as familial. Whole-genome sequencing studies of individuals with familial MD identified DTNA and FAM136A as candidate genes for autosomal dominant inheritance of MD. Although the exact roles of these genes in MD are unknown, FAM136A encodes a mitochondrial protein, and DTNA encodes a cytoskeletal protein involved in synapse formation and maintenance, important for maintaining the blood-brain barrier. It is also associated with a particular aquaporin. We tested vestibular and auditory function in dtna and fam136a knockout (KO) mice, using RotaRod and startle reflex-based clicker tests, respectively. Three-factor analysis of variance (ANOVA) results indicated that sex, age, and genotype were significantly correlated with reduced mean latencies to fall ("latencies") for male dtna KO mice, while only age was a significant factor for fam136a KO mice. Fam136a KO mice lost their hearing months before WTs (9-11 months vs. 15-20 months). In male dtna KO mice, divergence in mean latencies compared with other genotypes was first evident at 4 months of age, with older males having an even greater decrease. Our results indicate that fam136a gene mutations generate hearing problems, while dtna gene mutations produce balance deficits. Both mouse models should help to elucidate hearing loss and balance-related symptoms associated with MD.
Topics: Animals; Mice; Male; Meniere Disease; Reflex, Startle; Hearing Loss, Sensorineural; Vestibule, Labyrinth; Mutation
PubMed: 37461313
DOI: 10.1111/ejn.16083 -
Clinical Neurophysiology : Official... Oct 2021
Topics: Acoustic Stimulation; Humans; Prepulse Inhibition; Reflex, Startle
PubMed: 34456163
DOI: 10.1016/j.clinph.2021.08.005 -
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 -
Psychophysiology Dec 2022Trace fear conditioning is an important research paradigm to model aversive learning in biological or clinical scenarios, where predictors (conditioned stimuli, CS) and...
Trace fear conditioning is an important research paradigm to model aversive learning in biological or clinical scenarios, where predictors (conditioned stimuli, CS) and aversive outcomes (unconditioned stimuli, US) are separated in time. The optimal measurement of human trace fear conditioning, and in particular of memory retention after consolidation, is currently unclear. We conducted two identical experiments (N = 28, N = 28) with a 15-s trace interval and a recall test 1 week after acquisition, while recording several psychophysiological observables. In a calibration approach, we explored which learning and memory measures distinguished CS+ and CS- in the first experiment and confirmed the most sensitive measures in the second experiment. We found that in the recall test without reinforcement, only fear-potentiated startle but not skin conductance, pupil size, heart period, or respiration amplitude, differentiated CS+ and CS-. During acquisition without startle probes, skin conductance responses and pupil size responses but not heart period or respiration amplitude differentiated CS+ and CS-. As a side finding, there was no evidence for extinction of fear-potentiated startle over 30 trials without reinforcement. These results may be useful to inform future substantive research using human trace fear conditioning protocols.
Topics: Humans; Fear; Conditioning, Classical; Memory; Conditioning, Operant; Learning; Reflex, Startle; Extinction, Psychological
PubMed: 35675529
DOI: 10.1111/psyp.14119 -
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 -
Neuropsychiatric Disease and Treatment 2022The startle reflex is considered a primitive physiological reflex, a defense response that occurs in the organism when the body feels sudden danger and uneasiness,... (Review)
Review
The startle reflex is considered a primitive physiological reflex, a defense response that occurs in the organism when the body feels sudden danger and uneasiness, characterized by habituation and sensitization effects, and studies on the startle reflex often deal with pre-pulse inhibition (PPI) and sensorimotor gating. Under physiological conditions, the startle reflex is stable at a certain level, and when the organism is in a pathological state, such as stroke, spinal cord injury, schizophrenia, and other diseases, the reflex undergoes a series of changes, making it closely related to the progress of disease. This paper summarizes the startle reflex in physiological and pathological states by reviewing the databases of PubMed, Web of Science, Cochrane Library, EMBASE, China Biology Medicine, China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodical, Wanfang Data, and identifies and analyzes the startle reflex and excessive startle reaction disorder.
PubMed: 35237036
DOI: 10.2147/NDT.S351667 -
Ageing Research Reviews May 2020Inhibition plays a crucial role in many functional domains, such as cognition, emotion, and actions. Studies on cognitive aging demonstrate changes in inhibitory... (Review)
Review
Inhibition plays a crucial role in many functional domains, such as cognition, emotion, and actions. Studies on cognitive aging demonstrate changes in inhibitory mechanisms are age- and pathology-related. Prepulse inhibition (PPI) is the suppression of an acoustic startle reflex (ASR) to an intense stimulus when a weak prepulse stimulus precedes the startle stimulus. A reduction of PPI is thought to reflect dysfunction of sensorimotor gating which normally suppresses excessive behavioral responses to disruptive stimuli. Both human and rodent studies show age-dependent alterations of PPI of the ASR that are further compromised in Alzheimer's disease (AD). The auditory P50 gating, an index of repetition suppression, also is characterized as a putative electrophysiological biomarker of prodromal AD. This review provides the latest evidence of age- and AD-associated impairment of sensorimotor gating based upon both human and rodent studies, as well as the AD-related disruption of P50 gating in humans. It begins with a concise review of neural networks underlying PPI regulation. Then, evidence of age- and AD-related dysfunction of both PPI and P50 gating is discussed. The attentional/ emotional aspects of sensorimotor gating and the neurotransmitter mechanisms underpinning PPI and P50 gating are also reviewed. The review ends with conclusions and research directions.
Topics: Acoustic Stimulation; Aging; Alzheimer Disease; Humans; Neural Inhibition; Prepulse Inhibition; Reaction Time; Reflex, Startle
PubMed: 32092463
DOI: 10.1016/j.arr.2020.101028