The involvement of CRF1 receptor within the basolateral amygdala and dentate gyrus in the naloxone-induced conditioned place aversion in morphine-dependent mice.

Drug withdrawal-associated aversive memories trigger relapse to drug-seeking behavior. Corticotrophin-releasing factor (CRF) is an important mediator of the reinforcing properties of drugs of abuse. However, the involvement of CRF1 receptor (CRF1R) in aversive memory induced by opiate withdrawal has yet to be elucidated. We used the conditioned-place aversion (CPA) paradigm to evaluate the role of CRF1R on opiate withdrawal memory acquisition, along with plasticity-related processes that occur after CPA within the basolateral amygdala (BLA) and dentate gyrus (DG). Male mice were rendered dependent on morphine and injected acutely with naloxone before paired to confinement in a naloxone-associated compartment. The CPA scores as well as the number of TH-positive neurons (in the NTS-A2 noradrenergic cell group), and the expression of the transcription factors Arc and pCREB (in the BLA and DG) were measured with and without CRF1R blockade. Mice subjected to conditioned naloxone-induced morphine withdrawal robustly expressed CPA. Pre-treatment with the selective CRF1R antagonist CP-154,526 before naloxone conditioning session impaired morphine withdrawal-induced aversive memory acquisition. CP-154,526 also antagonized the enhanced number of TH-positive neurons in the NTS-A2 that was seen after CPA. Increased Arc expression and Arc-pCREB co-localization were seen in the BLA after CPA, which was not modified by CP-154,526. In the DG, CPA was accompanied by a decrease of Arc expression and no changes in Arc-pCREB co-localization, whereas pre-treatment with CP-154,526 induced an increase in both parameters. These results indicate that CRF-CRF1R pathway could be a critical factor governing opiate withdrawal memory storage and retrieval and might suggest a role for TH-NA pathway in the effects of withdrawal on memory. Our results might indicate that the blockade of CRF1R could represent a promising pharmacological treatment strategy approach for the attenuation of the relapse to drug-seeking/taking behavior triggered by opiate withdrawal-associated aversive memories.

A mutation in the Z-line Cypher/ZASP protein is associated with arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an important cause of malignant arrhythmia and sudden death particularly in young people. Although it is considered a desmosomal disease, mutations in non-desmosomal genes have also been identified. We report on a family where a mutation in LDB3 is associated with this condition. The index case and first and second degree relatives underwent a complete clinical evaluation: physical examination, electrocardiography (ECG), signal-averaged ECG, 2D echocardiogram, cardiac magnetic resonance and 24-h monitoring. After ruling out mutations in the five desmosomal genes, genetic testing by means of Next Generation Sequencing was carried out on the proband. A heterozygous missense mutation in LDB3 c.1051A>G was identified. This result was confirmed by subsequent Sanger DNA sequencing. Another six carriers were identified amongst her relatives. Three subjects fulfilled the criteria for a definitive diagnosis of ARVC and one reached a borderline diagnosis. In conclusion, this is the first family with ARVC where a mutation in LDB3 is associated with ARVC. Next generation sequencing arises as a particular useful tool to point to new causative genes in ARVC.