Un fàrmac redueix en ratolins la por causada per traumes previs

Haver viscut una experiència traumàtica afavoreix la persistència de la por associada a un estímul aversiu, una por condicionada que es pot alleujar en ratolins amb una sola dosi de 7,8-dihidroxiflavona, un derivat flavonoide que potencia nous aprenentatges emocionals. Així ho demostra un treball publicat a American Journal of Psychiatry realitzat per investigadors de la Universitat d'Emory (Estats Units) i de la UAB, que consideren que el fàrmac podria ser eficaç per tractar trastorns d'estrès post traumàtic, de pànic i fòbies en persones.Vivir una experiencia traumática favorece la persistencia del miedo asociado a un estímulo adverso, un miedo condicionado que se puede mitigar en ratones con una sola dosis de 7,8-dihidroxiflavona, un derivado flavonoide que potencia nuevos aprendizajes emocionales. Así lo demuestra un trabajo publicado en American Journal of Psychiatry, realizado por investigadores de la Universidad de Emory (Estados Unidos) y de la UAB, que consideran que el fármaco podría ser eficaz para tratar trastornos de estrés post-traumático, de pánico y fobias en personas.Living a traumatic experience favours the persistence of fear associated with an aversive stimulus, known as fear conditioning and which, in mice, can be eased with a single dosis of 7,8-Dihydroxyflavone, a type of flavonoid which boosts the ability to acquire new emotional habits. These findings were published in the American Journal of Psychiatry in a study carried out by researchers at Emory University, USA, and UAB, who consider that the drug could be used in the effective treatment of post- traumatic stress, panic and phobia disorders in persons

Personality cannot be predicted from the power of resting state EEG

In the present study we asked whether it is possible to decode personality traits from resting state EEG data. EEG was recorded from a large sample of subjects (N = 309) who had answered questionnaires measuring personality trait scores of the 5 dimensions as well as the 10 subordinate aspects of the Big Five. Machine learning algorithms were used to build a classifier to predict each personality trait from power spectra of the resting state EEG data. The results indicate that the five dimensions as well as their subordinate aspects could not be predicted from the resting state EEG data. Finally, to demonstrate that this result is not due to systematic algorithmic or implementation mistakes the same methods were used to successfully classify whether the subject had eyes open or eyes closed and whether the subject was male or female. These results indicate that the extraction of personality traits from the power spectra of resting state EEG is extremely noisy, if possible at all.Comment: 14 pages, 4 figure

Sex differences in the behavioural and hypothalamic-pituitary-adrenal response to contextual fear conditioning in rats

This is the author's version of a work that was accepted for publication in Hormones and behavior. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Hormones and behavior, Vol. 66 No. 5 (Nov. 2014), p. 713-723In recent years, special attention is being paid to sex differences in susceptibility to disease. In this regard, there is evidence that male rats present higher levels of both cued and contextual fear conditioning than females. However, little is known about the concomitant hypothalamic-pituitary-adrenal (HPA) axis response to those situations which is critical in emotional memories. Here, we studied the behavioural and HPA responses of male and female Wistar rats to context fear conditioning using electric footshock as the aversive stimulus. Fear-conditioned rats showed a much greater ACTH and corticosterone response than those merely exposed to the fear conditioning chamber without receiving shocks. Moreover, males presented higher levels of freezing whereas HPA axis response was greater in females. Accordingly, during the fear extinction tests, female rats consistently showed less freezing and higher extinction rate, but greater HPA activation than males. Exposure to an open-field resulted in lower activity/exploration in fear-conditioned males, but not females, suggesting greater conditioned cognitive generalization in males than females. It can be concluded that important sex differences in fear conditioning are observed in both freezing and HPA activation, but the two set of variables are affected in the opposite direction: enhanced behavioural impact in males, but enhanced HPA responsiveness in females. Thus, the role of sex differences on fear-related stimuli may depend on the variables chosen to evaluate it, the greater responsiveness of the HPA axis in females perhaps being an important factor to be further explored

Deoxygedunin, a Natural Product with Potent Neurotrophic Activity in Mice

Gedunin, a family of natural products from the Indian neem tree, possess a variety of biological activities. Here we report the discovery of deoxygedunin, which activates the mouse TrkB receptor and its downstream signaling cascades. Deoxygedunin is orally available and activates TrkB in mouse brain in a BDNF-independent way. Strikingly, it prevents the degeneration of vestibular ganglion in BDNF −/− pups. Moreover, deoxygedunin robustly protects rat neurons from cell death in a TrkB-dependent manner. Further, administration of deoxygedunin into mice displays potent neuroprotective, anti-depressant and learning enhancement effects, all of which are mediated by the TrkB receptor. Hence, deoxygedunin imitates BDNF's biological activities through activating TrkB, providing a powerful therapeutic tool for treatment of various neurological diseases

Effects of Tac2 pathway blockade on fear memory consolidation, circulating steroids expression, and mRNA and protein expression in the Central Amygdala

This dataset includes the source data related to the submission of the article "Sex differences in fear memory consolidation via Tac2 signaling in mice" to Nature Communications. It includes fear memory consolidation affections after the administration of a Neurokinin 3 Receptor antagonist including behavioral and molecular data related to sex-steroids and amygdalar mRNA and protein expression

Sex differences in the behavioural and hypothalamic-pituitary-adrenal response to contextual fear conditioning in rats

This is the author's version of a work that was accepted for publication in Hormones and behavior. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Hormones and behavior, Vol. 66 No. 5 (Nov. 2014), p. 713-723In recent years, special attention is being paid to sex differences in susceptibility to disease. In this regard, there is evidence that male rats present higher levels of both cued and contextual fear conditioning than females. However, little is known about the concomitant hypothalamic-pituitary-adrenal (HPA) axis response to those situations which is critical in emotional memories. Here, we studied the behavioural and HPA responses of male and female Wistar rats to context fear conditioning using electric footshock as the aversive stimulus. Fear-conditioned rats showed a much greater ACTH and corticosterone response than those merely exposed to the fear conditioning chamber without receiving shocks. Moreover, males presented higher levels of freezing whereas HPA axis response was greater in females. Accordingly, during the fear extinction tests, female rats consistently showed less freezing and higher extinction rate, but greater HPA activation than males. Exposure to an open-field resulted in lower activity/exploration in fear-conditioned males, but not females, suggesting greater conditioned cognitive generalization in males than females. It can be concluded that important sex differences in fear conditioning are observed in both freezing and HPA activation, but the two set of variables are affected in the opposite direction: enhanced behavioural impact in males, but enhanced HPA responsiveness in females. Thus, the role of sex differences on fear-related stimuli may depend on the variables chosen to evaluate it, the greater responsiveness of the HPA axis in females perhaps being an important factor to be further explored

Personality cannot be predicted from the power of resting state EEG

In the present study we asked whether it is possible to decode personality traits from resting state EEG data. EEG was recorded from a large sample of subjects (n=289) who had answered questionnaires measuring personality trait scores of the 5 dimensions as well as the 10 subordinate aspects of the Big Five. Machine learning algorithms were used to build a classifier to predict each personality trait from power spectra of the resting state EEG data. The results indicate that the five dimensions as well as their subordinate aspects could not be predicted from the resting state EEG data. Finally, to demonstrate that this result is not due to systematic algorithmic or implementation mistakes the same methods were used to successfully classify whether the subject had eyes open or closed. These results indicate that the extraction of personality traits from the power spectra of resting state EEG is extremely noisy, if possible at all

PACAP-PAC1R modulates fear extinction via the ventromedial hypothalamus

Altres ajuts: Fundación Koplovitz; NIH: P50 MH115874, F32MH125634, K08 DK118201; VA Merit and Department of Defense; Instituto de la Mujer: 235/09Exposure to traumatic stress can lead to fear dysregulation, which has been associated with posttraumatic stress disorder (PTSD). Previous work showed that a polymorphism in the PACAP-PAC1R (pituitary adenylate cyclase-activating polypeptide) system is associated with PTSD risk in women, and PACAP (ADCYAP1)-PAC1R (ADCYAP1R1) are highly expressed in the hypothalamus. Here, we show that female mice subjected to acute stress immobilization (IMO) have fear extinction impairments related to Adcyap1 and Adcyap1r1 mRNA upregulation in the hypothalamus, PACAP-c-Fos downregulation in the Medial Amygdala (MeA), and PACAP-FosB/ΔFosB upregulation in the Ventromedial Hypothalamus dorsomedial part (VMHdm). DREADD-mediated inhibition of MeA neurons projecting to the VMHdm during IMO rescues both PACAP upregulation in VMHdm and the fear extinction impairment. We also found that women with the risk genotype of ADCYAP1R1 rs2267735 polymorphism have impaired fear extinction

Sex differences in fear memory consolidation via Tac2 signaling in mice

Altres ajuts: NARSAD Young Investigator Grant #22434; FJC2018-037958-I (MCIyU)Memory formation is key for brain functioning. Uncovering the memory mechanisms is helping us to better understand neural processes in health and disease. Moreover, more specific treatments for fear-related disorders such as posttraumatic stress disorder and phobias may help to decrease their negative impact on mental health. In this line, the Tachykinin 2 (Tac2) pathway in the central amygdala (CeA) has been shown to be sufficient and necessary for the modulation of fear memory consolidation. CeA-Tac2 antagonism and its pharmacogenetic temporal inhibition impair fear memory in male mice. Surprisingly, we demonstrate here the opposite effect of Tac2 blockade on enhancing fear memory consolidation in females. Furthermore, we show that CeA-testosterone in males, CeA-estradiol in females and Akt/GSK3β/β-Catenin signaling both mediate the opposite-sex differential Tac2 pathway regulation of fear memory. The Tachykinin 2 (Tac2) pathway in the central amygdala is sufficient and necessary for modulating fear memory consolidation. The authors show that silencing Tac2 neurons in the amygdala of male mice reduces fear expression, while fear expression in female mice is increased when manipulations are made during proestrus