Noise startle response

In a separate trial 24 h later, the animals are presented with a startle stimulus (e.g., loud noise 70-80 db, or air puff) and their activity is recorded as a baseline. The startle stimulus can be presented in four blocks of five startles each, with 30-35 s between each startle stimulus (7). Peak and amplitude of the startle response can be recorded (e.g., using a piezoelectric accelerometer) and digitized (18). 

In a study of 464 inner-city black infants, whose mothers were recruited prenatally based on alcohol and cocaine use during pregnancy, gestational age of less than 38 weeks was significantly correlated with cocaine use in the mothers (283). The infants were tested at 6.5,12, and 13 months of age the cocaine-exposed infants were more excitable, preferred faster frequencies of stimulation, had more difficulty habituating, were more reactive, and showed a greater startle response to noise. Moreover,... 

Startle Response A sudden noise will cause a startle response in people. The reaction is involuntary. Characteristics are vasoconstriction, an increase in blood pressure, dilation of pupils, and muscle contraction. Every time a loud... 

Sensitivity to Other Non-Social Exteroceptive Stimuli - Several studies indicate that PCPA increases various behavioral or neurological effects of electrical stimulation. Thresholds of current required to reinforce selfstimulation behavior are lowered by PCPA in rats,46 and PCPA has been reported to cause strong excitatory effects on intracranial self-stimulation rates in rats 3 days after treatment.47 5-HT-depleted animals have been reported to be more active than controls under conditions of extra environmental stimulation, particularly "novel" stimulation.18b,19c Cats "overreact to slight noises,"48 sensory thresholds are lowered,29 the responsiveness to a startle stimulus of rats with low basal responsiveness Is Increased,49 and habituation to an audltory-ellcited startle response, as measured by cortical electrical responses. Is reduced.50... 

Recticular net—A brain stem region that accentuates the reflex response to a sudden loud noise that results in an increased startle reaction. 

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