Lateral entorhinal cortex lesions impair local spatial frameworks

A prominent theory in the neurobiology of memory processing is that episodic memory is supported by contextually gated spatial representations in the hippocampus formed by combining spatial information from medial entorhinal cortex (MEC) with non-spatial information from lateral entorhinal cortex (LEC). However, there is a growing body of evidence from lesion and single-unit recording studies in rodents suggesting that LEC might have a role in encoding space, particularly the current and previous locations of objects within the local environment. Landmarks, both local and global, have been shown to control the spatial representations hypothesised to underlie cognitive maps. Consequently, it has recently been suggested that information processing within this network might be organized with reference to spatial scale with LEC and MEC providing information about local and global spatial frameworks respectively. In the present study, we trained animals to search for food using either a local or global spatial framework. Animals were re-tested on both tasks after receiving excitotoxic lesions of either the MEC or LEC. LEC lesioned animals were impaired in their ability to learn a local spatial framework task. LEC lesioned animals were also impaired on an object recognition task involving multiple local features but unimpaired at recognizing a single familiar object. Together, this suggests that LEC is involved in associating features of the local environment. However, neither LEC nor MEC lesions impaired performance on the global spatial framework task.Publisher PDFPeer reviewe

Episiotomy Scar Endometriosis a Rare Case Report

Endometriosis is defined as the presence of ectopic endometrial tissue outside the uterine cavity. It is a benign condition commonly observed in women of the reproductive age group. It can occur in both pelvic and extra-pelvic sites. Moreover, pelvic endometriosis is relatively common, as compared to extra-pelvic endometriosis. The most frequent site for pelvic endometriosis is ovary. It can also affect rectum, uterosacral ligaments, rectovaginal septum, urinary bladder. Extra-pelvic endometriosis is rare and when it occurs, does so more frequently in surgical scar sites, especially in caesarean section scar. Endometriosis in an episiotomy scar is extremely rare but can lead to significant morbidity in patients due to local infiltration. This condition can be diagnosed by the presence of the classical clinical triad of history of episiotomy, tender nodule at the scar site and cyclical pain. Surgical excision is very useful to assess the deeper extension of the lesion. Herein, we report one such case of episiotomy scar endometriosis

Distance- rather than location-based temporal judgements are more accurate during episodic recall in a real-world task

Definitions of episodic memory typically emphasise the importance of spatiotemporal frameworks in the contextual reconstruction of episodic retrieval. However, our ability to retrieve specific temporal contexts of experienced episodes is poor. This has bearing on the prominence of temporal context in the definition and evaluation of episodic memory, particularly among non-human animals. Studies demonstrating that rats rely on elapsed time (distance) rather than specific timestamps (location) to disambiguate events have been used to suggest that human episodic memory is qualitatively different to other species. We examined whether humans were more accurate using a distance- or location-based method for judging when an event happened. Participants (n = 57) were exposed to a series of events and then asked either when (e.g., 1:03 pm) or how long ago (HLA; e.g., 33 min) a specific event took place. HLA judgements were significantly more accurate, particularly for the most recently experienced episode. Additionally, a significantly higher proportion of participants making HLA judgements accurately recalled non-temporal episodic features across all episodes. Finally, for participants given the choice of methods for making temporal judgements, a significantly higher proportion chose to use HLA judgements. These findings suggest that human and non-human temporal judgements are not qualitatively different.PostprintPeer reviewe

Lateral entorhinal cortex lesions impair both egocentric and allocentric object-place associations

This work was supported by Biotechnology and Biological Sciences Research Council (BBSRC) grant BB/I019367/1.During navigation, landmark processing is critical either for generating an allocentric-based cognitive map or in facilitating egocentric-based strategies. Increasing evidence from manipulation and single-unit recording studies has highlighted the role of the entorhinal cortex in processing landmarks. In particular, the lateral (LEC) and medial (MEC) sub-regions of the entorhinal cortex have been shown to attend to proximal and distal landmarks, respectively. Recent studies have identified a further dissociation in cue processing between the LEC and MEC based on spatial frames of reference. Neurons in the LEC preferentially encode egocentric cues while those in the MEC encode allocentric cues. In this study, we assessed the impact of disrupting the LEC on landmark-based spatial memory in both egocentric and allocentric reference frames. Animals that received excitotoxic lesions of the LEC were significantly impaired, relative to controls, on both egocentric and allocentric versions of an object–place association task. Notably, LEC lesioned animals performed at chance on the egocentric version but above chance on the allocentric version. There was no significant difference in performance between the two groups on an object recognition and spatial T-maze task. Taken together, these results indicate that the LEC plays a role in feature integration more broadly and in specifically processing spatial information within an egocentric reference frame.Publisher PDFPeer reviewe

Treatment of depression in low-level residential care facilities for the elderly

Background: The rate of recognition and treatment of depressed older people in nursing homes is low. Data from the low-level residential care population have not been reported. This study aimed to collect information about the treatment of depression among older persons living in low-level residential care (hostels).Method: The participants comprised 300 elderly residents from ten low-level residential care facilities from various suburbs in metropolitan Melbourne. The participants were interviewed by a trained clinical psychologist to determine the presence or absence of major or minor depressive disorder using the Structured Clinical Interview for DSM-IV Axis I Disorder (SCID-I). Each participant was also administered the Standardized Mini-mental State Examination (SMMSE) to determine level of cognitive function. The clinical psychologist then reviewed all cases in consultation with a geropsychiatrist experienced in the diagnosis of depression among older people, prior to assigning a diagnosis of depression.Results: An important finding in this study was the low treatment for currently depressed residents, with less than half of those in the sample who were depressed receiving treatment. However, 61 of the 96 residents out of the sample of 300 who were on antidepressants were not currently depressed.Conclusion: There is an under recognition and under treatment of currently depressed older people in low-level residential care facilities (hostels) just as has been reported in studies in nursing homes. However, there are high numbers receiving antidepressants who are not currently depressed.<br /

The prevalence and recognition of major depression among low-level aged care residents with and without cognitive impairment

Previous research has demonstrated a high level of depression in nursing homes. The current study was designed to determine the prevalence of depression, using a structured diagnostic interview, among older people with and without mild-moderate cognitive impairment residing in low-level care facilities. The results demonstrated that, consistent with previous research in nursing homes, 16.9% of older people were diagnosed with major depressive disorder. Less than half of these cases had been detected or treated. Individuals with moderate cognitive impairment were more likely to be depressed, but cognitive impairment did not appear to act as a strong impediment to the detection of depression by general practitioners. A low awareness of their use of antidepressant medications was demonstrated among older people prescribed this treatment, including those with normal cognitive function. Reasons for the poor recognition of depression among older people are discussed

International Labor Standards, Soft Regulation, and National Government Roles

[Excerpt] In this article, we briefly describe the different approaches to the regulation of international labor standards, and then argue for a new role for national governments based on soft rather than hard regulation approaches. We argue that this new role shows potential for significantly enhancing progress in international labor standards, since it enables governments to articulate a position without having to deal with the enforcement issues that hard regulation mandates. We justify this new role for governments based on the increasing use of soft regulation in the international arena. Of course, this approach is not without its own problems, but given that existing approaches have all provided imperfect solutions to the problem of improving labor standards globally, re-visiting the role of national governments is in our view, highly important