Sex-dependent behavioral and prefrontal BDNF mRNA responses to extinction training and short-term citalopram after fear conditioning in rats
Fear conditioning is widely used to model selected PTSD-relevant fear-related responses in rodents, particularly persistent freezing after an aversive cue. However, this paradigm does not reproduce the full clinical syndrome of PTSD. The present stud...
Key Findings
Fear conditioning is widely used to model selected PTSD-relevant fear-related responses in rodents, particularly persistent freezing after an aversive cue. However, this paradigm does not reproduce the full clinical syndrome of PTSD. The present study compared extinction training, short-term citalopram treatment, and their combination in male and female rats, with behavioral outcomes and prefrontal BDNF mRNA expression evaluated as sex-dependent readouts. Male and female Wistar rats were subjected to auditory fear conditioning using three footshocks (0.8 mA, 3 s each; 30 s inter-shock interval), each preceded by a 75 dB auditory cue. Extinction training and/or citalopram (30 mg/kg, i.p.) were administered at 1 h, 24 h, and 48 h after the onset of fear conditioning. Freezing behavior, open-field locomotor activity and rearing, and hot-plate nociceptive latency were assessed after the intervention period. Prefrontal BDNF mRNA expression was quantified by RT-qPCR in selected groups. Extinction training reduced freezing behavior in both sexes, and the combined citalopram + extinction group showed an additional reduction compared with extinction alone in males. Citalopram alone did not significantly reduce freezing under the present short-term dosing schedule. Locomotor activity was not significantly changed within either sex. Rearing increased after extinction-based intervention, whereas nociceptive latency decreased after extinction and citalopram + extinction. Prefrontal BDNF mRNA expression was unchanged in males but increased in females after extinction and citalopram + extinction. These findings support sex-dependent behavioral and molecular responses to extinction-based intervention after fear conditioning. The molecular findings should be interpreted as exploratory because BDNF was assessed only at the mRNA level, in selected groups, and with a small sample size (n = 3/group).
Why This Matters for Body-Mind Practice
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