Mammals evolved a potent fear-motivated defensive system capable of single-trial fear learning that shows no forgetting over the lifespan of the animal. The basolateral amygdala complex (BLA) is considered an essential component of this conditional fear learning system. However, recent studies challenge this view and suggest that plasticity within other brain regions (i.e., central nucleus of the amygdala) may be crucial for fear conditioning. In the present study, we examine the mnemonic limits of contextual fear conditioning in the absence of the BLA using overtraining and by measuring remote fear memories. After excitotoxic lesions of the BLA were created, animals underwent overtraining and were tested at recent and remote memory intervals. Here we show that animals with BLA lesions can learn normal levels of fear. However, this fear memory loses its adaptive features: it is acquired slowly and shows substantial forgetting when remote memory is tested. Collectively, these findings suggest that fear-related plasticity acquired by brain regions outside of the BLA, unlike those acquired in the intact animals, do so for a relatively time-limited period.fear conditioning ͉ forgetting ͉ remote memory ͉ savings F ailure to defend against an environmental threat such as predation exacts an extreme cost on adaptive fitness (1). Unlike a single missed feeding or mating opportunity, a single failure to defend means you will have no future opportunities to pass on your genes. As a consequence, mammals have evolved a potent fear-motivated defensive system that is capable of singletrial learning (2) and shows no forgetting over the lifespan of the animal (3). Prior studies suggest that such memories are normally established and permanently maintained within the basolateral complex of the amygdala (BLA) (3-7). Typically, damage to the BLA eliminates the acquisition and expression of Pavlovian fear memories across a wide spectrum of mammals, including humans (8) and rodents (5, 6, 9-13). Both electrophysiological and molecular markers of neural activity within the BLA reveal a learning-and retrieval-specific pattern of activation (14-18). Moreover, blockade of NMDA receptors or de novo protein synthesis within the BLA disrupts the acquisition and consolidation of fear memories (19)(20)(21)(22)(23). In addition, regardless of whether fear memories are 1 day or 1.5 years old, posttraining BLA lesions completely abolish the expression of fear (3). Collectively, such findings are consistent with a mnemonic role of the BLA in fear learning.However, recent studies have challenged this view and suggest that plasticity in other brain regions are capable of supporting fear conditioning (24,25). Indeed, there is growing evidence that fear conditioning can be established in the absence of the BLA. In particular, deficits resulting from either lesions or inactivations of the BLA can be overcome with extensive overtraining (7,(25)(26)(27). Furthermore, both Zimmerman et al. (25) and Wilensky et al. (24) have recently shown that disrup...

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Purpose: Phantom limb syndrome (PLSd) is a frequent chronic complication post amputation and is difficult to manage with conventional medicine. Acupuncture has been shown to be effective in the management of other chronic pain conditions but little is known about the effectiveness of acupuncture for the management of PLSd. The study is nested in a larger study evaluating the feasibility of acupuncture for treating PLSd and aimed to explore the experience of PLSd and establish the acceptability of acupuncture intervention to treat PLSd.Methods: Study design comprised of a case study approach using multiple cases. One off semi-structured interviews were conducted with a purposive sample of 15 lower limb amputees 1-3 months post-surgery, with past or current experience of PLSd. Interviews explored participants' experience of PLSd and perceived acceptability of acupuncture intervention. Framework analysis was used to analyse data.Results: 6 key themes were identified during analysis; suffering (prior to amputation), acceptance and coping with the loss of a limb, real and physical phantoms, living with a phantom, being informed about PLSd, acupuncture acceptability. Additionally, outcome measures for the feasibility study were substantiated for ease of completion and relevance. Acupuncture was generally considered an acceptable intervention regardless of positive or negative past experience and few concerns were expressed. Local needling of the residual limb was considered acceptable. PLSd was perceived as a real and physical pain and participants used numerous and often metaphorical descriptions. PLSd frequently disrupted sleep and negatively affected wellbeing and mood.Conclusion: The study contributes to existing evidence exploring the experience of PLSd and identified that PLSd is a bothersome and annoying condition which affects quality of life. Findings suggest that amputees suffering from PLSd would be willing to try a complementary medicine (acupuncture) approach to help manage this condition.Contact: Esme Trevelyan, trevelye@lsbu.ac.uk / Nicola Robinson, nicky.robinson@lsbu.ac.uk http://dx.

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