Irene Delia Martijena

Bio: Irene Delia Martijena is an academic researcher from National University of Cordoba. The author has contributed to research in topics: Memory consolidation & Basolateral amygdala. The author has an hindex of 18, co-authored 29 publications receiving 842 citations.

Gabaergic modulation of the stress response in frontal cortex and amygdala

Abstract: GABAergic neurotransmission is thought to play an important role in the modulation of the central response to stress. In the present study we evaluate the influence of a brief restraint exposure on GABA-stimulated chloride influx in diverse brain areas presumed to have a major role in the mediation of emotional behaviors following aversive stimulation. A reduced chloride uptake after stress exposure was only observed in frontal cortex and amygdala. Moreover, rats subjected to such stressor performed an anxiogenic behavior when exposed later to the elevated plus-maze. A comparable behavior in the elevated plus-maze was observed between animals that were allowed to chew during the restraint experience and those without any stressful manipulation, suggesting that chewing served as an efficient coping behavioral strategy during such threatening situations. In order to explore if chewing during the restraint experience could suppress the reduction in GABA-stimulated chloride uptake induced by this stressor, rats were allowed or not to chew during restraint and in both cases GABA-stimulated chloride influx was assayed in frontal cortex and amygdala. The finding of this experiment showed that restrained rats that have the possibility to chew exhibited a similar GABA-stimulated chloride uptake in cortical tissue to that shown by control, unstressed rats. Moreover, chewing in response to restraint attenuated the reduction of GABA-stimulated chloride uptake in amygdala, supporting the notion that chewing is an effective coping response to restraint. These experiments suggest that a reduced GABAergic inhibitory control in these areas could be implicated in the emotional sequelae generated by this uncontrollable stressor and that the suppression of this reduction seems to be associated with the occurrence of coping behavioral response to such fear-inducing stimulus.

Chronic Mild Stress (CMS) Revisited: Consistency and Behavioural-Neurobiological Concordance in the Effects of CMS

Abstract: The chronic mild stress (CMS) model of depression has high validity but has in the past been criticized for being difficult to replicate. However, a large number of recent publications have confirmed

Measuring reward with the conditioned place preference (CPP) paradigm: update of the last decade.

Abstract: Conditioned place preference (CPP) continues to be one of the most popular models to study the motivational effects of drugs and non-drug treatments in experimental animals. This is obvious from a steady year-to-year increase in the number of publications reporting the use this model. Since the compilation of the preceding review in 1998, more than 1000 new studies using place conditioning have been published, and the aim of the present review is to provide an overview of these recent publications. There are a number of trends and developments that are obvious in the literature of the last decade. First, as more and more knockout and transgenic animals become available, place conditioning is increasingly used to assess the motivational effects of drugs or non-drug rewards in genetically modified animals. Second, there is a still small but growing literature on the use of place conditioning to study the motivational aspects of pain, a field of pre-clinical research that has so far received little attention, because of the lack of appropriate animal models. Third, place conditioning continues to be widely used to study tolerance and sensitization to the rewarding effects of drugs induced by pre-treatment regimens. Fourth, extinction/reinstatement procedures in place conditioning are becoming increasingly popular. This interesting approach is thought to model certain aspects of relapse to addictive behavior and has previously almost exclusively been studied in drug self-administration paradigms. It has now also become established in the place conditioning literature and provides an additional and technically easy approach to this important phenomenon. The enormous number of studies to be covered in this review prevented in-depth discussion of many methodological, pharmacological or neurobiological aspects; to a large extent, the presentation of data had to be limited to a short and condensed summary of the most relevant findings.

Mechanisms of fear extinction

Abstract: Excessive fear and anxiety are hallmarks of a variety of disabling anxiety disorders that affect millions of people throughout the world. Hence, a greater understanding of the brain mechanisms involved in the inhibition of fear and anxiety is attracting increasing interest in the research community. In the laboratory, fear inhibition most often is studied through a procedure in which a previously fear conditioned organism is exposed to a fear-eliciting cue in the absence of any aversive event. This procedure results in a decline in conditioned fear responses that is attributed to a process called fear extinction. Extensive empirical work by behavioral psychologists has revealed basic behavioral characteristics of extinction, and theoretical accounts have emphasized extinction as a form of inhibitory learning as opposed to an erasure of acquired fear. Guided by this work, neuroscientists have begun to dissect the neural mechanisms involved, including the regions in which extinction-related plasticity occurs and the cellular and molecular processes that are engaged. The present paper will cover behavioral, theoretical and neurobiological work, and will conclude with a discussion of clinical implications.