The present study is part of an ongoing series of experiments aimed at delineation of the neural pathways that mediate fear-potentiated startle, a model of conditioned fear in which the acoustic startle reflex is enhanced when elicited in the presence of a light previously paired with shock. A number of cortical areas that might be involved in relaying information about the visual conditioned s...

In experiment 1, we assessed the role of the primate amygdala and hippocampus in the acquisition of learned fear measured with fear-potentiated startle. Three groups of six rhesus monkeys were prepared with bilateral ibotenic acid lesions of the amygdaloid complex and the hippocampus or were sham operated. Selective ibotenic acid lesions of the amygdala, but not the hippocampus, blocked the acq...

A single action potential in one of a pair of reticulospinal neurons, the Mauthner cells, precedes a short-latency electromyographic response of the trunk and tail musculature on the opposite side of the body and a fast startle response in gold®sh. It has been postulated that not only the Mauthner cell, but also an array of neurons can trigger or participate in fast startle responses (Eaton et ...

The magnitude of the acoustic startle response can be reduced by a relatively weak sound presented immediately before the startle-eliciting sound; this phenomenon has been termed prepulse inhibition (PPI). Previous studies reported that PPI was present in the decerebrate rat, indicating that the primary neural pathways mediating PPI are located in the brainstem. The present study investigated t...

Cortisol release in a stressful situation can be beneficial for memory encoding and memory consolidation. Stimuli, such as odors, related to the stressful episode may successfully cue memory contents of the stress experience. The current investigation aimed at testing the potency of stress to influence startle responsivity 24 hr later and to implicitly reactivate emotional memory traces trigger...

Drugs thought to increase intracellular levels of cAMP were infused intrathecally into the subarachnoid space of the lumbar spinal cord, and the effects on the acoustic startle response in rats were measured. Intrathecal infusions of the cAMP analogs dibutyryl cAMP or 8-bromo cAMP (12.5-100 micrograms) produced marked, dose-dependent increases in startle amplitude compared to the infusion of ar...

AIMS An assessment of the acoustic startle response (ASR) and prepulse inhibition (PPI) of ASR in laboratory animals is used to model human anxiety and psychotic states, respectively. The aim of the study was to evaluate ASR and PPI in alcohol-naive male and female Warsaw alcohol high-preferring (WHP) and Warsaw alcohol low-preferring (WLP) rats. METHODS ASR and PPI were assessed in two separ...

AIMS Little is known about changes in the modulation of the startle reflex when patients go through an alcohol-dependence treatment in an outpatient facility. In the current study, the affective modulation of the cue-related startle reflex has been used to evaluate changes in the emotional processing of alcohol-related stimuli that occurred after a standard cognitive-behavioral intervention, an...

BACKGROUND The acoustic startle reflex (ASR) is a rapid, involuntary movement to sound, found in many species. The ASR can be modulated by external stimuli and internal state, making it a useful tool in many disciplines. ASR data collection and interpretation varies greatly across laboratories making comparisons a challenge. NEW METHOD Here we investigate the animal movement associated with a...

Short-term habituation is a basic form of learning that is analyzed in different species and using different behavioral models. Previous studies on mechanisms of short-term habituation yielded evidence for a potential role of group III metabotropic glutamate receptors (mGluRIIIs). Here we tested the hypothesis that mGluRIII mediate short-term habituation of startle in rats, combining electrophy...