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Neuroscience and Biobehavioral Reviews Jun 2017Acoustic startle response (ASR) modification procedures, especially prepulse inhibition (PPI), are increasingly used as behavioral measures of auditory processing and... (Review)
Review
Acoustic startle response (ASR) modification procedures, especially prepulse inhibition (PPI), are increasingly used as behavioral measures of auditory processing and sensorimotor gating in rodents due to their perceived ease of implementation and short testing times. In practice, ASR and PPI procedures are extremely variable across animals, experimental setups, and studies, and the interpretation of results is subject to numerous caveats and confounding influences. We review considerations for modification of the ASR using acoustic stimuli, and we compare the sensitivity of PPI procedures to more traditional operant psychoacoustic techniques. We also discuss non-auditory variables that must be considered. We conclude that ASR and PPI measures cannot substitute for traditional operant techniques due to their low sensitivity. Additionally, a substantial amount of pilot testing must be performed to properly optimize an ASR modification experiment, negating any time benefit over operant conditioning. Nevertheless, there are some circumstances where ASR measures may be the only option for assessing auditory behavior, such as when testing mouse strains with early-onset hearing loss or learning impairments.
Topics: Acoustic Stimulation; Animals; Hearing; Hearing Loss; Mice; Reflex, Startle; Sensory Gating
PubMed: 28327385
DOI: 10.1016/j.neubiorev.2017.03.009 -
Emotion (Washington, D.C.) Jun 2015Because healthy physical and mental functioning depends on the ability to regulate emotions, it is important to identify moderators of such regulations. Whether mental...
Because healthy physical and mental functioning depends on the ability to regulate emotions, it is important to identify moderators of such regulations. Whether mental fatigue, subsequent to the depletion of cognitive resources, impairs explicit emotion regulation to negative stimuli is currently unknown. This study explored this possibility. In a within-subject design over 2 separate sessions, healthy individuals performed easy (control session) or difficult (depletion session) cognitive tasks. Subsequently, they were presented with neutral and negative pictures, with instructions to either maintain or regulate (i.e., reduce) the emotions evoked by the pictures. Emotional reactivity was probed with the startle reflex. The negative pictures evoked a similar aversive state in the control and depletion sessions as measured by startle potentiation. However, subjects were able to down-regulate their aversive state only in the control session, not in the depletion session. These results indicate that mental fatigue following performance of cognitive tasks impairs emotion regulation without affecting emotional reactivity. These findings suggest that mental fatigue needs to be incorporated into models of emotion regulation.
Topics: Adult; Cognition; Emotional Adjustment; Emotions; Female; Healthy Volunteers; Humans; Male; Mental Fatigue; Photic Stimulation; Reflex, Startle; Work
PubMed: 25706833
DOI: 10.1037/emo0000058 -
Neuropharmacology May 2019Glutamate dysregulation is known to contribute to many psychiatric disorders including schizophrenia. Aberrant cortico-striatal activity and therefore glutamate levels...
Glutamate dysregulation is known to contribute to many psychiatric disorders including schizophrenia. Aberrant cortico-striatal activity and therefore glutamate levels might be relevant to this disease characterized by reduced prepulse inhibition (PPI), however, the molecular and behavioral mechanism of the pathophysiology of schizophrenia remains unclear. The focus of this study was to contribute to the current understanding of the glutamate and neurogranin (Ng) pathway, in relation to the cortico-striatal pathology of schizophrenia using a mouse model. A variant of the Ng gene has been detected in people with schizophrenia, implicating maladaptation of cortical glutamate signaling and sensorimotor gating. To test Ng-mediated PPI regulation in the mouse model, we utilized Ng null mice, viral-mediated Ng expression, and genetics approaches. Our results demonstrate that lack of Ng in mice decreases PPI. Ng over-expression in the prefrontal cortex (PFC) increases PPI, while Ng expression in either the nucleus accumbens (NAc) or hippocampus induces no change in PPI. Using optogenetics and chemogenetics, we identified that cortico-striatal activation is involved in PPI regulation. Finally, pharmacological regulation of Ng using glutamate receptor inhibitors demonstrated altered PPI between genotypes. In this study, we have investigated the impact of Ng expression on sensorimotor gating. This study contributes to a better understanding of the glutamatergic theory of schizophrenia, opening novel therapeutic avenues that may lead to glutamatergic treatments to ameliorate the symptoms of schizophrenia.
Topics: Acoustic Stimulation; Animals; Cerebral Cortex; Corpus Striatum; Mice; Mice, Knockout; Neural Pathways; Neurogranin; Reflex, Startle; Sensory Gating
PubMed: 30902751
DOI: 10.1016/j.neuropharm.2019.03.021 -
Psychophysiology Oct 2014The startle reflex is potentiated when anticipating emotional, compared to neutral, pictures. This study investigated the time course of reflex modulation during...
The startle reflex is potentiated when anticipating emotional, compared to neutral, pictures. This study investigated the time course of reflex modulation during anticipation and the impact of informative cuing on picture perception. Colors were used to signal the thematic content of emotional and neutral scenes; blink response modulation was measured by presenting acoustic startle probes 3, 2, or 1 s before picture onset or 2 s after picture onset. During anticipation of neutral scenes, blink magnitude showed increasing attenuation as picture onset approached, consistent with a modality-directed vigilance account. Conversely, when anticipating emotional scenes, reflex magnitude did not change over time, and blinks elicited closest to picture onset were potentiated compared to neutral. During perception, the expected reflex potentiation for unpleasant pictures was not found, suggesting that cuing may dampen defensive activation.
Topics: Arousal; Attention; Cues; Emotions; Female; Humans; Male; Photic Stimulation; Reflex, Startle; Visual Perception
PubMed: 24980898
DOI: 10.1111/psyp.12244 -
Journal of Traumatic Stress Feb 2022Early life adversity (ELA) increases the risk of problematic alcohol use and alcohol use disorder (AUD). However, it is unclear why some but not all ELA-exposed...
Early life adversity (ELA) increases the risk of problematic alcohol use and alcohol use disorder (AUD). However, it is unclear why some but not all ELA-exposed individuals develop problematic alcohol use. Research is needed to determine how this environmental risk factor interacts with underlying neurobehavioral vulnerabilities to problem alcohol use. Hypersensitivity to uncertain threats (U-threat) has been posited as an endophenotype for AUD that might aid in the refinement of mechanistic models of problematic alcohol use. Therefore, U-threat hypersensitivity requires examination as a possible individual difference factor that facilitates problematic alcohol use among ELA-exposed individuals. We examined the unique and interactive effects of ELA and U-threat reactivity on problem drinking and depressive and anxiety symptom severity. Participants (N = 131) completed a well-validated threat-of-shock task, and startle eyeblink potentiation was recorded to index aversive responding. Individuals also completed self-report measures of alcohol use, anxiety, and depressive symptoms. Results demonstrated a positive association between ELA and higher levels of problematic alcohol use at high levels of U-threat reactivity, β = .75, t = 3.93, p < .001. Conversely, at low levels of U-threat reactivity, ELA exposure was negatively associated with problematic alcohol use, β = -.49, t = -2.30, p = .023. There was no significant ELA x U-Threat reactivity interaction on anxiety or depression. U-threat response strongly interacts with ELA exposure, affecting the direction of the association between ELA and problem drinking. U-threat reactivity may be a promising target for the prevention and treatment of problematic drinking among ELA-exposed individuals.
Topics: Adult; Adverse Childhood Experiences; Alcoholism; Anxiety; Humans; Reflex, Startle; Stress Disorders, Post-Traumatic; Uncertainty
PubMed: 34263960
DOI: 10.1002/jts.22709 -
Schizophrenia Research Aug 2018
Topics: Acoustic Stimulation; Brain; Gait Disorders, Neurologic; Gene-Environment Interaction; Humans; Neural Inhibition; Phenotype; Reflex, Startle; Schizophrenia
PubMed: 29525460
DOI: 10.1016/j.schres.2018.02.042 -
Psychophysiology Dec 2015Previous research indicates that predictive cues can dampen subsequent defensive reactions. The present study investigated whether effects of cuing are specific to...
Previous research indicates that predictive cues can dampen subsequent defensive reactions. The present study investigated whether effects of cuing are specific to aversive stimuli, using modulation of the blink startle reflex as a measure of emotional reactivity. Participants viewed pictures depicting violence, romance/erotica, or mundane content. On half of all trials, a cue (color) predicted the content of the upcoming picture; on the remaining trials, scenes were presented without a cue. Acoustic startle probes were presented during picture viewing on trials with predictive cues and trials without a cue. Replicating previous studies, blink reflexes elicited when viewing violent pictures that had not been preceded by a cue were potentiated compared to uncued mundane scenes, and reflexes were attenuated when viewing scenes of erotica/romance that had not been cued. On the other hand, reflex potentiation when viewing scenes of violence (relative to mundane scenes) was eliminated when these pictures were preceded by a predictive cue, whereas scenes of romance prompted reliable reflex attenuation regardless of whether pictures were cued or not. Taken together, the data suggest that cuing elicits an anticipatory coping process that is specific to aversive stimuli.
Topics: Adolescent; Blinking; Cues; Emotions; Female; Humans; Male; Photic Stimulation; Reflex; Reflex, Startle; Young Adult
PubMed: 26399464
DOI: 10.1111/psyp.12546 -
The Journal of Physiology Apr 2017The corticospinal tract contributes to the control of finger muscles during precision and power grip. We explored the neural mechanisms contributing to changes in...
KEY POINTS
The corticospinal tract contributes to the control of finger muscles during precision and power grip. We explored the neural mechanisms contributing to changes in corticospinal excitability during these gripping configurations. Motor evoked potentials (MEPs) elicited by cortical, but not by subcortical, stimulation were more suppressed during power grip compared with precision grip and index finger abduction. Intracortical inhibition was more reduced during power grip compared with the other tasks. An acoustic startle cue, a stimulus that engages the reticular system, suppressed MEP size during power grip to a lesser extent than during the other tasks at a cortical level and this positively correlated with changes in intracortical inhibition. Our findings suggest that changes in corticospinal excitability during gross more than fine finger manipulations are largely cortical in origin and that the reticular system contributed, at least in part, to these effects.
ABSTRACT
It is well accepted that the corticospinal tract contributes to the control of finger muscles during precision and power grip in humans but the neural mechanisms involved remain poorly understood. Here, we examined motor evoked potentials elicited by cortical and subcortical stimulation of corticospinal axons (MEPs and CMEPs, respectively) and the activity in intracortical circuits (suppression of voluntary electromyography) and spinal motoneurons (F-waves) in an intrinsic hand muscle during index finger abduction, precision grip and power grip. We found that the size of MEPs, but not CMEPs, was more suppressed during power grip compared with precision grip and index finger abduction, suggesting a cortical origin for these effects. Notably, intracortical inhibition was more reduced during power grip compared with the other tasks. To further examine the origin of changes in intracortical inhibition we assessed the contribution of the reticular system, which projects to cortical neurons, and projects to spinal motoneurons controlling hand muscles. An acoustic startle cue, which engages the reticular system, suppressed MEP size during power grip to a lesser extent than during the other tasks and this positively correlated with changes in intracortical inhibition. A startle cue decreased intracortical inhibition, but not CMEPs, during power grip. F-waves remained unchanged across conditions. Our novel findings show that changes in corticospinal excitability present during power grip compared with fine finger manipulations are largely cortical in origin and suggest that the reticular system contributed, at least in part, to these effects.
Topics: Acoustic Stimulation; Adult; Evoked Potentials, Motor; Female; Hand Strength; Humans; Male; Motor Cortex; Pyramidal Tracts; Random Allocation; Reflex, Startle; Reticular Formation; Transcranial Magnetic Stimulation; Young Adult
PubMed: 27891607
DOI: 10.1113/JP273679 -
Physiology & Behavior Jul 2022Fear conditioning paradigms are frequently used in the translational study of anxiety and fear-related disorders. Accordingly, it is important to understand whether the...
Fear conditioning paradigms are frequently used in the translational study of anxiety and fear-related disorders. Accordingly, it is important to understand whether the measurement of fear conditioning responses is systematically influenced by an individual's race. Studies have found increased pain sensitivity and smaller physiological startle responses in Asian individuals, compared to White individuals; to our knowledge, no studies have evaluated whether skin conductance response (SCR) outcomes differ between Asian and White individuals. In a series of secondary data analyses, we investigated potential differences in skin conductance level (SCL), orienting SCR, unconditioned SCR, SCR to CS+ and CS-, differential SCR, and differential SCR non-responder status. In sample 1, Asian participants (n = 97) demonstrated a significantly smaller mean differential SCR compared to White participants (n = 86). No other between group differences were observed. In sample 2, there was no difference in mean differential SCR between Asian (n = 52) and White (n = 62) participants, although more Asian participants failed to show adequate skin conductance levels for study entry. To our knowledge, this is the first study to evaluate differences between Asian and White samples using skin conductance outcomes in a fear conditioning paradigm. We detected only subtle evidence for SCR differences between Asian and White samples, unlikely to reach significance outside large studies.
Topics: Anxiety Disorders; Conditioning, Classical; Extinction, Psychological; Fear; Galvanic Skin Response; Humans; Reflex, Startle
PubMed: 35398091
DOI: 10.1016/j.physbeh.2022.113802 -
Psychophysiology Aug 2017Predictability is an important characteristic of threat that impacts defensive motivation and attentional engagement. Supporting research has primarily focused on actual...
Predictability is an important characteristic of threat that impacts defensive motivation and attentional engagement. Supporting research has primarily focused on actual threat (e.g., shocks), and it is unclear whether the predictability of less intense threat (e.g., unpleasant pictures) similarly affects motivation and attention. The present study utilized a within-subject design and examined defensive motivation (startle reflex and self-reported anxiety) and attention (probe N100 and P300) in anticipation of shocks and unpleasant pictures during a no, predictable, and unpredictable threat task. This study also examined the impact of predictability on the P300 to shocks and late positive potential (LPP) to unpleasant pictures. The startle reflex and self-reported anxiety were increased in anticipation of both types of threat relative to no threat. Furthermore, startle potentiation in anticipation of unpredictable threat was greater for shocks compared to unpleasant pictures, but there was no difference for predictable threat. The probe N100 was enhanced in anticipation of unpredictable threat relative to predictable threat and no threat, and the probe P300 was suppressed in anticipation of predictable and unpredictable threat relative to no threat. These effects did not differ between the shock and unpleasant picture trials. Finally, the P300 and early LPP component were increased in response to unpredictable relative to predictable shocks and unpleasant pictures, respectively. The present study suggests that the unpredictability of unpleasant pictures increases defensive motivation, but to a lesser degree relative to actual threat. Moreover, unpredictability enhances attentional engagement in anticipation of, and in reaction to, both types of threat.
Topics: Adolescent; Anticipation, Psychological; Attention; Electroencephalography; Evoked Potentials; Fear; Female; Humans; Male; Motivation; Reflex, Startle; Uncertainty; Young Adult
PubMed: 28370078
DOI: 10.1111/psyp.12869