The paraventricular nucleus of the thalamus (PVT), which serves as a hub, receives dense projections from the medial prefrontal cortex (mPFC) and projects to the lateral division of central amygdala (CeL). The infralimbic (IL) cortex plays a crucial role in encoding and recalling fear extinction memory. Here, we found that neurons in the PVT and IL were strongly activated during fear extinction retrieval. Silencing PVT neurons inhibited extinction retrieval at recent time point (24 h after extinction), while activating them promoted extinction retrieval at remote time point (7 d after extinction), suggesting a critical role of the PVT in extinction retrieval. In the mPFC-PVT circuit, projections from IL rather than prelimbic cortex to the PVT were dominant, and disrupting the IL-PVT projection suppressed extinction retrieval. Moreover, the axons of PVT neurons preferentially projected to the CeL. Silencing the PVT-CeL circuit also suppressed extinction retrieval. Together, our findings reveal a new neural circuit for fear extinction retrieval outside the classical IL-amygdala circuit.

Objective Erythroderma is a very serious disease that affects nearly the entire cutaneous surface and are highly subjected to secondary hypoalbuminemia, infection, cardiovascular diseases, complex causes and high death rates. The article aimed to explore the etiology, comorbidities and complicated infection of erythroderma.Methods Retrospective analysis was conducted on clinical data of 95 cases of erythroderma in our department from January 2009 to August 2016. Observations were made on the patients' clinical characteristics, etiology and inducement, lab examination, complications and complicated infection.Results There were 73 first-episode and 22 recurrent patients, among which 14 cases are psoriasis as the basic disease. As to etiological factors, there were 57 cases secondary to other skin diseases (60%) and 25 cases by drug reactions (26%). As to inducing factors, there were 6 cases by upper respiratory tract infection, 38 cases by irrational application of glucocorticoids, and 7 cases by external stimulants (traditional Chinese medicine scrubbing and external medicinal liquor). The main complications were 38 cases of cardiovascular diseases (40%). The complicated infection rates of plasma albumin in patients <35g/L and ≥35g/L were 65.78% and 12.28%(P<0.01). The complicated infection rates of the patients with hypoalbuminemia and electrolyte disturbance were 44.2% and 25% respectively (P<0.05).Conclusion The erythroderma is mainly secondary to previous skin diseases, mostly psoriasis, with cardiovascular diseases as the main comorbidities. In clinical practice, importance should be attached to monitoring decreased plasma albumin level and electrolyte disturbances in order to reduce the risk of infection.