Increased fear response to contextual cues in mice lacking the 5-HT1A receptor
| Autor: | Kristen C. Klemenhagen, René Hen, Joshua A. Gordon, Denis J. David, Cornelius Gross |
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| Rok vydání: | 2005 |
| Předmět: |
Male
Light Context (language use) Motor Activity Developmental psychology Stress Disorders Post-Traumatic chemistry.chemical_compound Mice medicine Avoidance Learning Animals Fear conditioning Neurotransmitter Pharmacology Mice Knockout Electroshock Panic disorder Recognition Psychology Fear medicine.disease Psychiatry and Mental health Phenotype chemistry Knockout mouse Receptor Serotonin 5-HT1A Exploratory Behavior Anxiety 5-HT1A receptor Conditioning Operant Serotonin medicine.symptom Cues Psychology Neuroscience |
| Zdroj: | Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology. 31(1) |
| ISSN: | 0893-133X |
| Popis: | Serotonin 1A receptor knockout (5-HT1AR KO) mice exhibit increased behavioral inhibition in conflict tests. To gain further insight into their anxiety-related phenotype, we subjected these mice to additional behavioral tests. First, we considered whether behavioral inhibition in these knockout mice is a consequence of reduced exploratory motivation. The knockout mice engage in normal exploration during a light–dark test and normal exploration of a novel object in a familiar environment, suggesting that the anxiety-related phenotype is not due to reduced exploratory drive. Second, we tested whether these mice exhibit increased behavioral inhibition in response to any aversive cues, or whether this response depends on cue modality. Knockout mice respond normally to discrete aversive cues in the Vogel lick-suppression test, arguing that their phenotype is restricted to conflict tests based on complex or spatial aversive cues. Third, to probe the processing of spatial aversive cues, we assessed fear conditioning to contextual cues. After contextual fear conditioning, knockout and wild-type (WT) mice express freezing responses when exposed to the training environment. However, when placed in an ambiguous environment containing both conditioned and novel cues, the freezing response of knockout mice does not significantly decrease as it does in WT mice, suggesting that the knockout fear response is biased toward threatening cues. We hypothesize that this inappropriate generalization of fearful behavior to a context containing both fearful and neutral stimuli, a phenomenon that occurs in a subset of human anxiety disorders such as panic disorder and post-traumatic stress disorder, underlies the anxiety phenotype of 5-HT1AR KO mice. |
| Databáze: | OpenAIRE |
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