Host cell remodelling and protein trafficking

Inside their respective vertebrate hosts, Plasmodium spp spend most of their life residing within hepatocytes and erythrocytes, with large-scale infection of the latter responsible for the clinical symptoms associated with malaria. These parasites extensively remodel these host cells for a variety of purposes relating to both pathogenesis and maintaining growth. Remodelling of the erythrocytic stage has been most intensively studied in P. falciparum and is the subject of this chapter. To help remodel their hosts these parasites export hundreds of proteins into the erythrocytic compartment. This principally alters the architecture of the erythrocyte, rendering the host membrane more permeable to solutes and nutrients, and also increasing the rigidity and adhesiveness of the infected erythrocyte. Moreover, because erythrocytes lack a secretory apparatus, the parasite must also export many additional proteins to help traffic other proteins to their correct destination within the host cell. The functions of some of these exported proteins will be discussed as will recent progress that has been made in unravelling how exported proteins gain access to the host compartment.

Modulation of putative mirror neuron activity by both positively and negatively valenced affective stimuli: a TMS study

Research indicates that mirror neurons are important for social cognition, including emotion processing. Emerging evidence, however, also reveals that emotional stimuli might be capable of modulating human mirror neuron system (MNS) activity.

The current study used transcranial magnetic stimulation (TMS) to assess putative mirror neuron function following emotionally evocative images in twenty healthy adults.

Participants observed videos of either a transitive hand action or a static hand while undergoing TMS of the primary motor cortex. In order to examine the effect of emotion on the MNS, each video was preceded by an image of either a positive, negative or neutral valence.

MNS activity was found to be augmented by both the positive and negative (relative to neutral) stimuli, thus providing empirical support for a bi-directional link between emotion and the MNS, whereby both positively and negatively valenced stimuli are capable of facilitating mirror neuron activity. The potential adaptive significance of this finding is discussed. 

Function and structure of the mirror neuron system in autism

 Utilizing MRI, this thesis identified wide-spread brain abnormalities in autism. White matter deficits were more pronounced in the left hemisphere, attributable to atypical myelination. Regarding the mirror neuron system, functional anomalies were situated in the right, dorsal, premotor cortex which further demonstrated reduced functional connectivity with the inferior parietal lobule.

Trafficking and protection: theorising reintegration and defining success

Grounded upon research in Cambodia, a theory of ‘reintegration’ is proposed for victims of sex-trafficking and benchmarks for assessing success. Drawing upon a cosmopolitan conception of shared vulnerability, it is argued that a life lived with dignity chiefly depends upon access to either modernist or traditional forms of reciprocal recognition.

Exploring associations between gaze patterns and putative human mirror neuron system activity

The human mirror neuron system (MNS) is hypothesized to be crucial to social cognition. Given that key MNS-input regions such as the superior temporal sulcus are involved in biological motion processing, and mirror neuron activity in monkeys has been shown to vary with visual attention, aberrant MNS function may be partly attributable to atypical visual input. To examine the relationship between gaze pattern and interpersonal motor resonance (IMR; an index of putative MNS activity), healthy right-handed participants aged 18-40 (n = 26) viewed videos of transitive grasping actions or static hands, whilst the left primary motor cortex received transcranial magnetic stimulation. Motor-evoked potentials recorded in contralateral hand muscles were used to determine IMR. Participants also underwent eyetracking analysis to assess gaze patterns whilst viewing the same videos. No relationship was observed between predictive gaze and IMR. However, IMR was positively associated with fixation counts in areas of biological motion in the videos, and negatively associated with object areas. These findings are discussed with reference to visual influences on the MNS, and the possibility that MNS atypicalities might be influenced by visual processes such as aberrant gaze pattern.