Combined brain-derived neurotrophic factor with extinction training alleviate impaired fear extinction in an animal model of post-traumatic stress disorder.

Impaired fear memory extinction (Ext) is one of the hallmark symptoms of post-traumatic stress disorder (PTSD). However, since the precise mechanism of impaired Ext remains unknown, effective interventions have not yet been established. Recently, hippocampal-prefrontal brain-derived neurotrophic factor (BDNF) activity was shown to be crucial for Ext in naïve rats. We therefore examined whether decreased hippocampal-prefrontal BDNF activity is also involved in the Ext of rats subjected to a single prolonged stress (SPS) as a model of PTSD. BDNF levels were measured by enzyme-linked immunosorbent assay (ELISA), and phosphorylation of TrkB was measured by immunohistochemistry in the hippocampus and medial prefrontal cortex (mPFC) of SPS rats. We also examined whether BDNF infusion into the ventral mPFC or hippocampus alleviated the impaired Ext of SPS rats in the contextual fear conditioning paradigm. SPS significantly decreased the levels of BDNF in both the hippocampus and mPFC and TrkB phosphorylation in the ventral mPFC. Infusion of BDNF 24 hours after conditioning in the infralimbic cortex (ILC), but not the prelimbic cortex (PLC) nor hippocampus, alleviated the impairment of Ext. Since amelioration of impaired Ext by BDNF infusion did not occur without extinction training, it seems the two interventions must occur consecutively to alleviate impaired Ext. Additionally, BDNF infusion markedly increased TrkB phosphorylation in the ILC of SPS rats. These findings suggest that decreased BDNF signal transduction might be involved in the impaired Ext of SPS rats, and that activation of the BDNF-TrkB signal might be a novel therapeutic strategy for the impaired Ext by stress.

First- and second-line pharmacological treatment for delirium in general hospital setting-Retrospective analysis.

AIM: We examined the first- and second-line pharmacological treatment for delirium to determine which drugs were chosen, how and when second-line drugs were started, and the effectiveness and tolerability of those treatments. METHODS: A retrospective medical chart review was performed for delirium inpatients referred to the Department of Psychiatry, Hiroshima Citizens Hospital, from October 2011 to September 2012. Clinical diagnoses were based on ICD-10. We compared the baseline severity of delirium, duration needed for improvement, and rescue with antipsychotics between subjects given only first-line drugs and those switched to second-line drugs. RESULTS: We studied 194 consecutive patients including 127 men and 67 women whose average age was 76.5±9.8years. For first-line drugs, trazodone was most frequently prescribed (n=100, 51.5%), followed by quetiapine (n=57, 29.4%). Among patients treated with trazodone or quetiapine as first line treatment, 59 of 100 (59%) continued trazodone and 52 of 57 (91.2%) continued quetiapine. Duration needed for improvement did not differ significantly between patients treated with trazodone as a first line drug and those with quetiapine as same. CONCLUSION: Trazodone can be a candidate drug as one of the first line drugs for delirium.