Animals ; Reflex, Startle ; Models, Animal ; Acoustics

Prepulse inhibition (PPI) is suppression of the startle reflex when an intense startling stimulus is preceded by a weaker sensory stimulus (the prepulse). It is an operational measurement of sensorimotor gating mechanism to help human adapt to complex environment. This weak prepulse protect central cognitive processing by damping the effect of intense stimuli. Autistics cannot select out behaviorally important information from a lot of irrelevant resources and reflect abnormal gating mechanism and attentional abnormalities. Previous studies have not made agreement on whether autistic patients demonstrated deficits in PPI, because the results depend on age, sex, severity of the disease as well as the experimental parameters used. Moreover, these studies have not covered whether autistics have suffered deficits in higher-order processing. In this review, the "top-down" modulation of selective attention and subjective emotion are introduced into the PPI experiment. We also introduce fear conditioning and perceived spatial separation paradigm to further explore the interaction between autistic cognitive process and gating mechanism.
Attention ; Autistic Disorder ; Fear ; Humans ; Prepulse Inhibition ; Reflex, Startle

Early diagnosis of persistent abnormal reflexes may be of great significance to a more effective functioning of the cerebral palsied child. It is important to know the normal and abnormal reflex responses and their effect upon motor development for providing a basis for evaluation in the diagnosis and treatment of the cerebral palsied child. We studied 28 cerebral palsied children, between 1 to 12 years old, who were treated at Sam Yook Childrens Rehabilitation Center from May 1975 to December 1977. The pathologic reflexes were checked, and the relationship between pathologic reflexes and walking was compared. The following results were obtained. 1. The following were the most important pathologic reflexes in non-walking fgroup: a. Positive supporting reaction b. Protective extensor thrust c. Moro reflex 2. If they are present, the prognosis for walking ambulation was bad and surgery will not improve for the chances of walking.
Child ; Diagnosis ; Early Diagnosis ; Humans ; Prognosis ; Reflex ; Reflex, Abnormal ; Reflex, Startle ; Rehabilitation Centers ; Walking

Gap prepulse inhibition of acoustic startle (GPIAS) method has been used effectively for the objective assessment of tinnitus in animals. Among two types of enclosures for the GPIAS, the unconstrained type carries less risk of animal death due to the absence of binding stress in the enclosure, and lack of need for alteration to animal size variation as it grows. However, animals' voluntary movements, which have no relation to the startles evoked by acoustic stimuli, are problematic, as they cannot be excluded in the case of the unconstrained enclosure based GPIAS measurement system. In order to discount voluntary movements which are not associated with external acoustic stimuli, we propose the conditional random interstimulus interval (CR ISI) method for unconstrained enclosure based GPIAS measurement. With the proposed ISI method, the unconstrained enclosure based acoustic startle response measurement system has been implemented in this paper. As a result, the effectiveness of the proposed CR ISI method has been verified and compared with those of conventional ISI methods through animal experiments using SD-rats. The experimental results showed that abnormal startle responses and invalid GPIAS values caused by motion were prevented when our proposed CR ISI method was applied to our implemented system. It was also verified that our proposed CR ISI method is advantageous in reducing the total experimental time for acquiring normal startle responses and valid GPIAS values, compared to conventional ISI methods, since our proposed CR ISI can begin the acoustic stimulation only when the animal gets stable and motionless.
Acoustic Stimulation ; Acoustics ; Animal Experimentation ; Animals ; Integrin alpha2 ; Methods ; Prepulse Inhibition ; Reflex, Startle ; Tinnitus

The relative incidence of cerebral palsy has increased recently over that of poliomyelitis, due to the improvement in the social, medical, and economic status of our country. It is important to check the pathologic reflexes for diagnosis, treatment and prognosis of cerebral palsy. We studied 84 cerebral palsied patients, between 1 to 13 years old, who were treated at our Crippled Childrens Rehabilitation Center. The motor age and pathologic reflexes were checked, and pathologic reflexes were checked, and the relationship between pathologic reflexes and walking was compared. The following results were obtained. 1) With increasing of chronological age, there was a tendericy to increasing of motor age, but the mean motor age did not increase after 8 years in chronological age, and no more than to about 20 months. 2) With increasing of motor age, a tendency to decreasing of frequency of pathologic reflexes was shown. 3) The followings were the most important pathologic reflexes in non walking group: a) positive supporting reaction b) supine lying c) prone lying d) Moro reflex e) asymetrical tonic neck f) protective extensor thrust.
Cerebral Palsy ; Child ; Clinical Study ; Deception ; Diagnosis ; Humans ; Incidence ; Neck ; Poliomyelitis ; Prognosis ; Reflex ; Reflex, Startle ; Rehabilitation Centers ; Walking

Infants with Sandhoff disease typically appear normal until 3–6 months of age. As the disease progresses, they present with symptoms such as loss of motor skills, exaggerated startle response to loud noise, seizures, visual loss, and paralysis. We encountered a rare case of a 22-month-old girl with Sandhoff disease characterized by progressive motor weakness and dysphagia, who initially showed signs of aspiration at 20 months of age. The major problems related to dysphagia were oromotor dysfunction and abnormal feeding posture. Within 3 months of identification of difficulty in swallowing, the patient showed a significant decrease in food intake, with rapid deterioration of nutritional status. We report our case with a review of the literature.
Deglutition Disorders ; Deglutition* ; Eating ; Female ; Humans ; Infant ; Motor Skills ; Noise ; Nutritional Status ; Paralysis ; Posture ; Reflex, Startle ; Sandhoff Disease* ; Seizures

AIMTo inquire a new credible animal model in studies of startle conditioned reflex.

METHODSThrough the trials of combining a conditioned stimulus (a tone) with an unconditioned stimulus(a foot shock), the startle responses were established in animals by conditioned stimulus. Arterial blood pressure were measured before and after blocking basolateral and lateral amygdala with lidocaine.

RESULTSThe blood pressure was increased by the conditioned stimulus after four days training. When the basolateral amygdala was blocked by lidocaine, the blood pressure was not increased by the conditioned stimulus.

CONCLUSIONThe animal model used and verified in this experiment is a new credible chronic animal model in startle conditioned reflex by measuring arterial blood pressure.

Animals ; Arteries ; physiology ; Blood Pressure ; Conditioning, Classical ; physiology ; Female ; Male ; Models, Animal ; Rats ; Rats, Wistar ; Reflex, Startle ; physiology

OBJECTIVETo constitute the animal model of high frequency hearing loss and observer the temporal processing abilities of low frequency regions using prepulse inhibition of auditory startle response (gap-PPI).

METHODSTen guinea pigs were randomly grouped into two groups: the high frequency hearing loss group with six guinea pigs and the control group with four guinea pigs. The former group was exposed to 12 kHz tone at 110 dB SPL for 30 hours to establish the high frequency hearing loss above 8 kHz and the latter group received no stimulations. Before and two, four, six and eight weeks after noise exposure, gap-PPI and auditory brainstem response (ABR) were recorded in both groups. In the gap-PPI experiment, three different background noises as 0.5 - 2 kHz, 0.5 - 4 kHz and 0.5 - 8 kHz were applied to test the temporal gap.

RESULTSHigh frequency hearing loss above 8 kHz was shown two weeks after noise exposure. The averaged ABR thresholds of 16 kHz, 32 kHz and 48 kHz were elevated about 55 dB and shown statistical significance compared to those before exposure (P < 0.05). No significant difference of ABR thresholds were shown between 1 kHz, 2 kHz, 4 kHz and 8kHz before and after noise exposure (P > 0.05). In the control group, the ABR thresholds remained stable during experiment. In the gap-PPI test, two weeks after noise exposure of 8 kHz, the experiment group showed attenuated inhibition ability and recovered gradually four weeks after noise exposure. No statistical differences of inhibition ability at time points of two, four, six and eight weeks after noise exposure of 4 kHz were detected when compared with that of pre-exposure. Under the background noise of 2 kHz, the inhibition ability attenuated and reached statistical significance at 6 - 8 weeks after noise exposure.

CONCLUSIONThe high frequency hearing loss might induce an impairment of the temporal processing in the low frequency region.

Animals ; Auditory Threshold ; Evoked Potentials, Auditory, Brain Stem ; Female ; Guinea Pigs ; Hearing Loss, High-Frequency ; physiopathology ; Male ; Noise ; Reflex, Startle

Brain Stem ; physiology ; Humans ; Infant, Newborn ; Infant, Newborn, Diseases ; etiology ; Movement Disorders ; etiology ; Myoclonus ; etiology ; Reflex, Abnormal ; Reflex, Startle ; Tremor ; etiology

BACKGROUNDNicotine may improve schizophrenia patient's cognitive deficit symptoms. This study was to explore the chronic effects of smoking on prepulse inhibition of the startle reflex (PPI) and P50 in the patients with first-episode schizophrenia (FES).

METHODSThe event-related potentials (ERP) recording and analysis instrument made by Brain Products, Germany, was used to detect PPI and P50 in 49 male FES patients (FES group, n = 21 for smokers and n = 28 for non-smokers) and 43 normal male controls (control group, n = 19 for smokers and n = 24 for non-smokers).

RESULTSCompared with normal controls, the FES group had prolonged PPI latency when elicited by single stronger stimulus (P < 0.05); the FES group had prolonged PPI latency and increased PPI amplitude (P < 0.05, 0.01) when elicited by weak and strong stimuli. The FES group had lower PPI inhibition rate than normal controls (P < 0.05). Compared with normal controls, the FES group had increased P50-S2 amplitude and increased amplitude ratio S2/S1 (both P <0.05). In the control group, the smokers had a tendency of increase in P50-S2 amplitude (P > 0.05) and shorter P50-S2 latency (P < 0.05) than the non-smokers. The smokers had higher PPI amplitude than the non-smokers (P < 0.05). In the FES group, the smokers had higher P50-S1 amplitude, shorter P50-S2 latency, and higher amplitude ratio S2/S1 than the non-smokers (P < 0.05, 0.01). The smokers had higher PPI amplitude than the non-smokers (P < 0.05).

CONCLUSIONSThere is obvious PPI and P50 deficits in schizophrenic patients. However, these deficits are relatively preserved in the smokers compared with the non-smokers, which suggests that long-term smoking might partially improve the sensory gating in schizophrenic patients. Whether this conclusion can be deduced to female patients requires further follow-ups.

Adult ; Case-Control Studies ; Evoked Potentials ; drug effects ; physiology ; Humans ; Male ; Reflex, Startle ; physiology ; Schizophrenia ; physiopathology ; Smoking ; adverse effects ; Young Adult