Dataset Information

Long-lasting incubation of conditioned fear in rats.

ABSTRACT: BACKGROUND:In 1937, Diven reported that human fear responses to cues previously paired with shock progressively increase or incubate over 24 hours. Since then, fear incubation has been demonstrated in both humans and nonhumans. However, the difficulty of demonstrating long-lasting fear incubation in rodents has hampered the study of the underlying mechanisms of this incubation. Here, we describe a rat procedure where fear reliably incubates over time. METHODS:We trained food-restricted rats to lever-press for food pellets in daily 90-min sessions. We then gave each rat 100 30-sec tones co-terminating with a .5-sec .5-mA footshock over 10 days (10 pairings/day). Groups of rats (n = 10-15) were then given four presentations of the tone (the fear cue) 2, 15, 31, or 61 days after fear conditioning training and were assessed for conditioned suppression of lever-pressing. RESULTS:We found that conditioned fear responses were significantly higher 31 and 61 days after fear training than after 2 or 15 days. In control experiments, we showed that extensive tone-shock pairing is necessary for the emergence of fear incubation and that it is unlikely that non-associative factors contribute to this incubation. CONCLUSIONS:We describe a procedure for generating reliable and long-lasting conditioned fear incubation. Our procedure can be used to study mechanisms of fear incubation and might provide a model for studying the mechanisms of delayed-onset posttraumatic stress disorder that occur in a sub-population of people previously exposed to chronic stressors.

SUBMITTER: Pickens CL

PROVIDER: S-EPMC2740722 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Long-lasting incubation of conditioned fear in rats.

Pickens Charles L CL Golden Sam A SA Adams-Deutsch Tristan T Nair Sunila G SG Shaham Yavin Y

Biological psychiatry 20090123 10

<h4>Background</h4>In 1937, Diven reported that human fear responses to cues previously paired with shock progressively increase or incubate over 24 hours. Since then, fear incubation has been demonstrated in both humans and nonhumans. However, the difficulty of demonstrating long-lasting fear incubation in rodents has hampered the study of the underlying mechanisms of this incubation. Here, we describe a rat procedure where fear reliably incubates over time.<h4>Methods</h4>We trained food-restr ...[more]

PMID: 19167702

Similar Datasets

Project description:Social support, when provided following a traumatic experience, is associated with a lower incidence of stress-related psychiatric disorders. Our hypothesis was that providing a social interaction period with a naive conspecific would improve sleep architecture in response to cued fear conditioning in Wistar rats. Rats were randomly assigned to either the socially isolated or socially partnered groups. Rats assigned to the socially isolated group were individually housed following electrode implantation and fear conditioning. Rats assigned to the socially partnered group were initially paired-housed, and then one rat from each pair was randomly chosen for sleep electrode implantation and fear conditioning. Rats from both groups were habituated to a recording chamber, and baseline sleep was recorded over 22 hours. One day later (Training Day), they were fear-conditioned to 10 presentations of a tone (800 Hz, 90 dB, 5 sec) co-terminating with a mild electric foot shock (1.0 mA, 0.5 sec), at 30-sec intervals. While rats in the socially isolated group were left undisturbed in their home cage for 30-min, socially partnered rats interacted for 30 minutes with their non-stressed rat partner immediately after fear conditioning and while the auditory tones were presented on Days 1 and 14. The results indicated that social interaction increased sleep efficiency in partnered rats compared to isolated rats following the fear conditioning procedure. This was due to an increase in the amount of rapid eye movement sleep (REMS) during the light phase. Evaluation of REMS microarchitecture revealed that the increase in REMS was due to an increase in the number of single REMS episodes (siREMS), which represented a more consolidated REMS pattern. A surprising finding was that partnered rats had a greater number of sequential REMS episodes (seqREMS) at Baseline, on the Training Day and on Day 1 when compared to isolated rats. The greater number of seqREMS episodes in partnered rats may be due to the partnering procedure and not fear conditioning, as the effect was also seen at Baseline. Thus it appears that while the partnering procedure may have given rise to a fragmented REMS pattern, social partnering promoted a greater consolidation of REMS in response to the fear conditioning procedure.

Project description:Numerous behavioral paradigms have been developed to assess tinnitus-like behavior in animals. Nevertheless, they are often limited by prolonged training requirements, as well as an inability to simultaneously assess onset and lasting tinnitus behavior, tinnitus pitch or duration, or tinnitus presence without grouping data from multiple animals or testing sessions. To enhance behavioral testing of tinnitus, we developed a conditioned licking suppression paradigm to determine the pitch(s) of both onset and lasting tinnitus-like behavior within individual animals. Rats learned to lick water during broadband or narrowband noises, and to suppress licking to avoid footshocks during silence. After noise exposure, rats significantly increased licking during silent trials, suggesting onset tinnitus-like behavior. Lasting tinnitus-behavior, however, was exhibited in about half of noise-exposed rats through 7 weeks post-exposure tested. Licking activity during narrowband sound trials remained unchanged following noise exposure, while ABR hearing thresholds fully recovered and were comparable between tinnitus(+) and tinnitus(-) rats. To assess another tinnitus inducer, rats were injected with sodium salicylate. They demonstrated high pitch tinnitus-like behavior, but later recovered by 5 days post-injection. Further control studies showed that 1): sham noise-exposed rats tested with footshock did not exhibit tinnitus-like behavior, and 2): noise-exposed or sham rats tested without footshocks showed no fundamental changes in behavior compared to those tested with shocks. Together, these results demonstrate that this paradigm can efficiently test the development of noise- and salicylate-induced tinnitus behavior. The ability to assess tinnitus individually, over time, and without averaging data enables us to realistically address tinnitus in a clinically relevant way. Thus, we believe that this optimized behavioral paradigm will facilitate investigations into the mechanisms of tinnitus and development of effective treatments.

Dataset Information

Long-lasting incubation of conditioned fear in rats.

Publications

Long-lasting incubation of conditioned fear in rats.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets