62 research outputs found
Regulation and Restoration of Motoneuronal Synaptic Transmission During Neuromuscular Regeneration in the Pulmonate Snail Helisoma trivolvis
Regeneration of motor systems involves reestablishment of central control networks, reinnervation of muscle targets by motoneurons, and reconnection of neuromodulatory circuits. Still, how these processes are integrated as motor function is restored during regeneration remains ill defined. Here, we examined the mechanisms underlying motoneuronal regeneration of neuromuscular synapses related to feeding movements in the pulmonate snail Helisoma trivolvis. Neurons B19 and B110, although activated during different phases of the feeding pattern, innervate similar sets of muscles. However, the percentage of muscle fibers innervated, the efficacy of excitatory junction potentials, and the strength of muscle contractions were different for each cell’s specific connections. After peripheral nerve crush, a sequence of transient electrical and chemical connections formed centrally within the buccal ganglia. Neuromuscular synapse regeneration involved a three-phase process: the emergence of spontaneous synaptic transmission (P1), the acquisition of evoked potentials of weak efficacy (P2), and the establishment of functional reinnervation (P3). Differential synaptic efficacy at muscle contacts was recapitulated in cell culture. Differences in motoneuronal presynaptic properties (i.e., quantal content) were the basis of disparate neuromuscular synapse function, suggesting a role for retrograde target influences. We propose a homeostatic model of molluscan motor system regeneration. This model has three restoration events: (1) transient central synaptogenesis during axonal outgrowth, (2) intermotoneuronal inhibitory synaptogenesis during initial neuromuscular synapse formation, and (3) target-dependent regulation of neuromuscular junction formation
Welfare conditionality and social marginality: the folly of the tutelary state?
In a contemporarnb 1`vby evolution of the tutelary state, welfare reform in the United Kingdom has been characterised by moves towards greater conditionality and sanctioning. This is influenced by the attributing responsibility for poverty and unemployment to the behaviour of marginalised individuals. Mead (1992) has argued that the poor are dependants who ought to receive support on condition of certain restrictions imposed by a protective state that will incentivise engagement with support mechanisms. This article examines how the contemporary tutelary and therapeutic state has responded to new forms of social marginality. Drawing on a series of in-depth interviews conducted with welfare claimants with an offending background in England and Scotland, the article examines their encounters with the welfare system and argues that alienation, rather than engagement with support, increasingly characterises their experiences
Monitoring fever treatment behaviour and equitable access to effective medicines in the context of initiatives to improve ACT access: baseline results and implications for programming in six African countries
BACKGROUND: Access to artemisinin-based combination therapy (ACT) remains limited in high malaria-burden countries, and there are concerns that the poorest people are particularly disadvantaged. This paper presents new evidence on household treatment-seeking behaviour in six African countries. These data provide a baseline for monitoring interventions to increase ACT coverage, such as the Affordable Medicines Facility for malaria (AMFm). METHODS: Nationally representative household surveys were conducted in Benin, the Democratic Republic of Congo (DRC), Madagascar, Nigeria, Uganda and Zambia between 2008 and 2010. Caregivers responded to questions about management of recent fevers in children under five. Treatment indicators were tabulated across countries, and differences in case management provided by the public versus private sector were examined using chi-square tests. Logistic regression was used to test for association between socioeconomic status and 1) malaria blood testing, and 2) ACT treatment. RESULTS: Fever treatment with an ACT is low in Benin (10%), the DRC (5%), Madagascar (3%) and Nigeria (5%), but higher in Uganda (21%) and Zambia (21%). The wealthiest children are significantly more likely to receive ACT compared to the poorest children in Benin (OR = 2.68, 95% CI = 1.12-6.42); the DRC (OR = 2.18, 95% CI = 1.12-4.24); Madagascar (OR = 5.37, 95% CI = 1.58-18.24); and Nigeria (OR = 6.59, 95% CI = 2.73-15.89). Most caregivers seek treatment outside of the home, and private sector outlets are commonly the sole external source of treatment (except in Zambia). However, children treated in the public sector are significantly more likely to receive ACT treatment than those treated in the private sector (except in Madagascar). Nonetheless, levels of testing and ACT treatment in the public sector are low. Few caregivers name the national first-line drug as most effective for treating malaria in Madagascar (2%), the DRC (2%), Nigeria (4%) and Benin (10%). Awareness is higher in Zambia (49%) and Uganda (33%). CONCLUSIONS: Levels of effective fever treatment are low and inequitable in many contexts. The private sector is frequently accessed however case management practices are relatively poor in comparison with the public sector. Supporting interventions to inform caregiver demand for ACT and to improve provider behaviour in both the public and private sectors are needed to achieve maximum gains in the context of improved access to effective treatment
Activity-dependent induction of functional secretory properties at cultured neuromuscular synapses of Helisoma
Wartime Experiences and Indigenous Identities in the Japanese Empire
Further research on the operations of empire and on Indigenous histories offers the opportunity to examine how Indigenous communities in the Japanese Empire experienced competing currents of loyalty and identity during the Pacific War. This article examines how three Indigenous populations—Ainu, Indigenous Taiwanese and Micronesian Islanders—survived the ideological and social pressures of an empire at war and, despite the intense assimilationist demands of Japan’s kōminka program and traumatic wartime experiences, retained cultural identities sufficiently robust to allow expression at the end of the century in the form of action to maintain community lives apart from, while engaged with, the nation-state
Regulation and Restoration of Motoneuronal Synaptic Transmission During Neuromuscular Regeneration in the Pulmonate Snail Helisoma trivolvis
- …