Counteractive effects of antenatal glucocorticoid treatment on D1 receptor modulation of spatial working memory

RATIONALE: Antenatal exposure to the glucocorticoid dexamethasone dramatically increases the number of mesencephalic dopaminergic neurons in rat offspring. However, the consequences of this expansion in midbrain dopamine (DA) neurons for behavioural processes in adulthood are poorly understood, including working memory that depends on DA transmission in the prefrontal cortex (PFC). OBJECTIVES: We therefore investigated the influence of antenatal glucocorticoid treatment (AGT) on the modulation of spatial working memory by a D1 receptor agonist and on D1 receptor binding and DA content in the PFC and striatum. METHODS: Pregnant rats received AGT on gestational days 16-19 by adding dexamethasone to their drinking water. Male offspring reared to adulthood were trained on a delayed alternation spatial working memory task and administered the partial D1 agonist SKF38393 (0.3-3 mg/kg) by systemic injection. In separate groups of control and AGT animals, D1 receptor binding and DA content were measured post-mortem in the PFC and striatum. RESULTS: SKF38393 impaired spatial working memory performance in control rats but had no effect in AGT rats. D1 binding was significantly reduced in the anterior cingulate cortex, prelimbic cortex, dorsal striatum and ventral pallidum of AGT rats compared with control animals. However, AGT had no significant effect on brain monoamine levels. CONCLUSIONS: These findings demonstrate that D1 receptors in corticostriatal circuitry down-regulate in response to AGT. This compensatory effect in D1 receptors may result from increased DA-ergic tone in AGT rats and underlie the resilience of these animals to the disruptive effects of D1 receptor activation on spatial working memory

The material soul: Strategies for naturalising the soul in an early modern epicurean context

We usually portray the early modern period as one characterised by the ‘birth of subjectivity’ with Luther and Descartes as two alternate representatives of this radical break with the past, each ushering in the new era in which ‘I’ am the locus of judgements about the world. A sub-narrative called ‘the mind-body problem’ recounts how Cartesian dualism, responding to the new promise of a mechanistic science of nature, “split off” the world of the soul/mind/self from the world of extended, physical substance—a split which has preoccupied the philosophy of mind up until the present day. We would like to call attention to a different constellation of texts—neither a robust ‘tradition’ nor an isolated ‘episode’, somewhere in between—which have in common their indebtedness to, and promotion of an embodied, Epicurean approach to the soul. These texts follow the evocative hint given in Lucretius’ De rerum natura that ‘the soul is to the body as scent is to incense’ (in an anonymous early modern French version). They neither assert the autonomy of the soul, nor the dualism of body and soul, nor again a sheer physicalism in which ‘intentional’ properties are reduced to the basic properties of matter. Rather, to borrow the title of one of these treatises (L’Âme Matérielle), they seek to articulate the concept of a material soul. We reconstruct the intellectual development of a corporeal, mortal and ultimately material soul, in between medicine, natural philosophy and metaphysics, including discussions of Malebranche and Willis, but focusing primarily on texts including the 1675 Discours anatomiques by the Epicurean physician Guillaume Lamy; the anonymous manuscript from circa 1725 entitled L’Âme Matérielle, which is essentially a compendium of texts from the later seventeenth century (Malebranche, Bayle) along with excerpts from Lucretius; and materialist writings such Julien Offray de La Mettrie’s L’Homme-Machine (1748), in order to articulate this concept of a ‘material soul’ with its implications for notions of embodiment, materialism and selfhood

Neuroimaging the consciousness of self: Review, and conceptual-methodological framework

We review neuroimaging research investigating self-referential processing (SRP), that is, how we respond to stimuli that reference ourselves, prefaced by a lexical-thematic analysis of words indicative of “self-feelings”. We consider SRP as occurring verbally (V-SRP) and non-verbally (NV-SRP), both in the controlled, “top-down” form of introspective and interoceptive tasks, respectively, as well as in the “bottom-up” spontaneous or automatic form of “mind wandering” and “body wandering” that occurs during resting state. Our review leads us to outline a conceptual and methodological framework for future SRP research that we briefly apply toward understanding certain psychological and neurological disorders symptomatically associated with abnormal SRP. Our discussion is partly guided by William James’ original writings on the consciousness of self

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Varieties of neo-colonialism: government accounting reforms in Anglophone and Francophone Africa - Benin and Ghana compared

This study compares government accounting reforms in an Anglophone and a Francophone African country, namely Ghana and Benin, with respect to neo-colonialism. The data draws from interviews with local officials concerned with government accounting, documents and documentaries. The focus lay on the perceived effectiveness of reforms, and their formulation and implementation. In both countries their former colonial powers, Britain and France, still influence accounting through economic means (through monetary systems), international financial institutions, political advisors, Northern accounting associations and neo-patrimonialism. However, their use of these differs. While France structures her control mostly around the monetary system established during colonialism, Britain relies on its post-colonial infrastructure and accounting profession, and concedes much influence to the USA, essentially through international financial institutions. France exerts more direct control through advisors than Britain (with the USA). The French approach is conceptualized as coercive-neo-colonialism and the British as soft-neo-colonialism. Despite international financial institutions’ pervasive presence, they are not monolithic agents with a uniform role and influence in Ghana and Benin, and good governance aims to increase civil service capacity, financial transparency and accountability remain problematic

South African professional super rugby players’ lived experiences of career-related traumatic injuries : a phenomenological analysis

Abstract: Historically, non-career-ending traumatic rugby injuries have been defined, researched, and treated from a predominantly biological perspective. However, dimensional approaches (e.g., the bio-psycho-social model) have highlighted the need to incorporate both psychological and social dimensions into understanding the effects of traumatic rugby injuries on the entire lebenswelt of the individual experiencing them. Recently, certain research has outlined a general stage-wise process or progression that traumatically injured sports people, including rugby players, seem to experience as a result of being injured. Generally speaking, these stages comprise reactions to the onset of the traumatic injury, emotional reactions to the injury, and the subsequent rehabilitation processes leading to recovery. The aim of the present study was to describe the lived experiences of traumatically injured South African Super Rugby players. Hence, it was decided that the employment of a qualitative, descriptive phenomenological methodology was well suited to achieving this general research aim. Purposive sampling was employed apropos the research participants (i.e., three participants who had sustained a traumatic rugby injury while competing in the 2017 Super Rugby competition were selected). Each participant was required to be between the ages of 24 and 30 years old. This age group was chosen in an attempt to maintain a degree of consistency between the possible psychosocial experiences described by the participants. Open-ended interviews were conducted in order to gather information, while allowing for as much spontaneity and authenticity in the participant responses as possible. This study produced a variety of rich descriptions of the experience of a traumatic rugby injury from the perspectives of the three traumatically injured South African Super Rugby player participants. Common themes indicate that the experience of a traumatic rugby injury can be seen to exist within three stages, that is, initial reactions to the traumatic injury / injury onset, emotional reactions to the traumatic injury and subsequent reactions to the traumatic injury (including the rehabilitation process). Each of the stages comprises various sub-themes (i.e., the traumatically injured South African Super Rugby player attempts to remain positive about the injury, while appraising the severity of the injury). Emotional reactions include fear responses to the need for surgical interventions, and to the possibility of financial losses concomitant with feelings of loss related to foregone career opportunities. Subsequently, the traumatically injured South African SuperM.A. (Psychology

Electrical responses to short-range kinematogram displays: An occipital lobe global motion process in humans?

Recently some evidence has been presented to suggest global organising function within V1. Gray, Konig, Engel and Singer (1989) presented the results of multi-unit responses simultaneously recorded from spatially separate sites in cortical area 17 of the cat. Presenting appropriately oriented moving light bars, the authors found that neurons in spatially separate columns could synchronise their response. They found "that synchronisation depends on global features of the stimuli such as coherent motion and continuity, which are not reflected by the local responses alone" (p. 335). Such a process described for the cat, may underlie the pattern of results found here for the extraction of coherent motion from kinematogram displays in humans

An eye-tracking AFROC study of the influence of experience and training on chest X-ray interpretation

Four observer groups with different levels of expertise were tested in an investigation into the comparative nature of expert performance. The radiological task was the detection and localisation of significant pulmonary nodules in postero-anterior views of the chest in adults. Three test banks of 40 images were used. The observer groups were 6 experienced radiologists, 6 experienced radiographers prior to a six month training programme in chest image interpretation, the same radiographers after their training programme, and 6 fresher undergraduate radiography students. Eye tracking was carried out on all observers to demonstrate differences in visual activity and nodule detection performance was measured with an AFROC technique. Detection performances of the four groups showed the radiologists and radiographers after training were measurably superior at the task. The eye-tracking parameters saccadic length, number of fixations visual coverage and scrutiny time per film were measured for all subjects and compared. The missed nodules fixated and not fixated were also determined for the radiologist group. Results have shown distinct stylistic differences in the visual scanning strategies between the experienced and inexperienced observers that we believe can be generalised into a description of characteristics of expert versus non-expert performance. The findings will be used in the educational programme of image interpretation for non-radiology practitioners