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The present study sought to determine appropriate instrumentation for amplification and calibration of cages used to measure the acoustic startle response in rats. Fourier analysis indicated that the characteristic frequency of the rat startle response is about 5-15 Hz. This value was consistent in cages differing widely in resonant frequency, among several(More)
CRF(1) receptor antagonists have been proposed as novel pharmacological treatments for depression, anxiety and stress disorders. The primary goal of the present study was to evaluate the effects of the CRF(1) receptor antagonist, CP 154,526, in the separation-induced vocalization (SIV) model of anxiety. Nine- to 11-day-old rat pups were separated from their(More)
The whole-body acoustic startle response is a short-latency reflex mediated by a relatively simple neural circuit in the lower brainstem and spinal cord. The amplitude of this reflex is markedly enhanced by moderate fear levels, and less effectively increased by higher fear levels. Extensive evidence indicates that the amygdala plays a key role in the(More)
The amplitude of the acoustic startle response in rats is decreased if the startle stimulus is preceded by a nonstartle-eliciting auditory stimulus. This sensory gating phenomenon, known as prepulse inhibition, is diminished in schizophrenic individuals. In rats, the noncompetitive glutamate antagonist MK-801 disrupts prepulse inhibition. The present study(More)
Fear potentiation of the acoustic startle reflex was produced by eliciting startle responses in the presence of a light that had been previously paired with a shock. Buspirone (0.6-5.0 mg/kg) and gepirone (1.25-10.0 mg/kg), but not their common metabolite, 1-PP (0.5-40 mg/kg), produced a dose-dependent reduction of fear-potentiated startle. These doses of(More)
Chronic decerebrate rats, maintained in good condition for 31-84 postoperative days, showed significant within-session habituation of the acoustic startle response. However, they showed no habituation over days under conditions that produced significant response deficits in controls. The decerebrates' stimulus-provoked response deficits may have endured for(More)
The present study evaluated the role of various neurotransmitter systems in mediating buspirone's blockade of the fear-potentiated startle effect, where acoustic startle amplitude is normally increase in the presence of a light previously paired with a shock. Large lesions of the dorsal and median raphe nuclei or IP injections of the serotonin antagonists(More)
This study sought to determine where drugs that are known to alter sensorimotor reactivity measured with the acoustic startle reflex ultimately act within the acoustic startle pathway. To do this, startle was elicited either acoustically or electrically within various nuclei believed to comprise the acoustic startle pathway. Direct infusion of serotonin(More)
BACKGROUND There is a need for a rapid-acting, non-injection, acute treatment for agitation. AIMS To evaluate inhaled loxapine for acute treatment of agitation in schizophrenia. METHOD This phase III, randomised, double-blind, placebo-controlled, parallel-group study (ClinicalTrials.gov number NCT00628589) enrolled 344 individuals who received one, two(More)