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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 -
Clinical Neurophysiology : Official... Oct 2021
Topics: Acoustic Stimulation; Humans; Prepulse Inhibition; Reflex, Startle
PubMed: 34456163
DOI: 10.1016/j.clinph.2021.08.005 -
Epileptic Disorders : International... Oct 2022The Moro reflex (MR) is a primitive reflex that disappears after the first three months of life. It was described by the Austrian paediatrician Ernst Moro (1874-1951) in...
The Moro reflex (MR) is a primitive reflex that disappears after the first three months of life. It was described by the Austrian paediatrician Ernst Moro (1874-1951) in 1918, although the earliest visual representation of the MR dates back to the first half of the 14th Century, in a fresco by Ambrogio Lorenzetti (1290-1348). The neural centre underlying the MR is located in the lower part of the brainstem since it can be elicited also in anencephalic infants, as shown by the Austrian neurologist Eduard Gamper (1887-1938) in the first medical description of anencephaly (1926). The MR is due to the activation of an archaic neural circuit present in the newborn, the activity of which is later inhibited by the upper brain structures. Given their semiological resemblance, epileptic spasms and generalized tonic-clonic seizures might be due (at least partly) to the pathological activation of the same neural archaic circuit involved in the genesis of the MR. The neuronal network underlying these different phenomena might be located in the pons. In these seizure types, the activation of the same neural circuitry involved in the MR could occur through either direct excitation or through an indirect "liberating" mechanism, secondary to epileptic disruption of cortical inhibitory control on subcortical structures. The movements of the upper extremities in epileptic spasms, in the initial phase of generalized tonic-clonic seizures, and the MR might involve a distinct neural circuitry, which is (or becomes) hyperexcitable as a consequence of a pathological condition (epilepsy) or physiological brain immaturity (the MR).
Topics: Electroencephalography; Epilepsy; Epilepsy, Tonic-Clonic; Humans; Infant; Infant, Newborn; Reflex, Startle; Seizures; Spasm; Spasms, Infantile
PubMed: 35904039
DOI: 10.1684/epd.2022.1471 -
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 -
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 -
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 -
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 -
Neuroscience and Biobehavioral Reviews Jan 2022Play has been recognized as a complex and diverse set of behaviors that has been difficult to define. Play can range from rough and tumble play among rats to a human... (Review)
Review
Play has been recognized as a complex and diverse set of behaviors that has been difficult to define. Play can range from rough and tumble play among rats to a human child playing a computer game. Play has been understood to exist in multiple forms such as social, object, and locomotor (Burghardt, 2005). In this article we review the literatures on the neural basis of social play, on heart rate variability, on behavioral switching and set-shifting, on prepulse inhibition of the acoustic startle reflex, and on learning at the level of the basal ganglia. Each of these neuronal pathways, aside from heart rate variability, is rooted in the parafascicular nucleus of the thalamus, an important neural substrate for social play. We argue that social play optimally balances a number of opposing neural pathways by engaging systems involved in safety versus danger (heart rate variability), automatized reactions versus learned reactions to new stimuli (behavioral switching and set-shifting), and gating relevant versus less relevant stimuli (prepulse inhibition of the acoustic startle reflex). The idea that play, in addition to its role in interpersonal adaptation to social life, may have a central role in optimizing flexibility and creativity in individual response to novelty has been explored by previous authors (Huizinga, 1955; Spinka et al., 2001; Pellegrini et al., 2007; Pellis and Pellis, 2017). In this paper we explore the possible underlying neural basis for this function of play, having to do with balancing various neural networks, and in doing so propose an expanded understanding of the nature and function of social play.
Topics: Acoustic Stimulation; Animals; Neural Inhibition; Neural Pathways; Prepulse Inhibition; Rats; Reflex, Startle
PubMed: 34767879
DOI: 10.1016/j.neubiorev.2021.11.005 -
Journal of Clinical Neurophysiology :... Nov 2019It has been well documented that a prepared response can be triggered at short latency following the presentation of a loud acoustic stimulus that evokes a reflexive... (Review)
Review
It has been well documented that a prepared response can be triggered at short latency following the presentation of a loud acoustic stimulus that evokes a reflexive startle response. Different hypotheses have been proposed for this so-called "StartReact" effect, although there is still much debate surrounding the physiological mechanisms involved in the observed reduction in reaction time (RT). In this review, we outline the various neurophysiological explanations underlying the StartReact effect and summarize the data supporting, and at times opposing, each possibility. Collectively, the experimental results do not unequivocally support a single explanation and we suggest the most parsimonious mechanism may involve a hybrid framework involving a distribution of neural pathways. Specifically, we propose that multiple node networks at the cortical, brainstem, and spinal levels are involved in response preparation and initiation, and the relative contributions of these structures depends on the type of stimulus delivered and the type of movement required. This approach may lead to greater understanding of the pathways involved in response preparation, initiation, and execution for both healthy and motor disordered populations.
Topics: Acoustic Stimulation; Female; Humans; Male; Movement; Reaction Time; Reflex, Startle
PubMed: 31688329
DOI: 10.1097/WNP.0000000000000582 -
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