Essay in Judgment: Reading for Aesthetics in Mansfield Park

My dissertation demonstrates how Mansfield Park, which contains philosophically compelling claims about judgment generally and aesthetic judgment specifically, makes these claims through a reading experience that is itself an exercise in aesthetic judgment. Although this experience could be had by any actual reader of the novel, the experience of every actual reader depends upon her willingness to measure the exercise of her own faculty of judgment against that of the self-reflective, aesthetically disinterested, yet emotionally engaged reader whom the novel itself hypothesizes. With this hypothesized reader, I argue, the novel encourages readers to realize this ideal of aesthetic judgment while also explaining the various ways they might fall short. This hypothesized reader, I argue further, strives to follow a demand similar to Mikhail Bakhtins demand in Art and Answerability for each individual to make art and life answerable to one another. Mansfield Park challenges readers to make art and life answerable primarily through a double plot structure; narrative techniques that complicate the distance between characters and readers; and the portrayal of the characters various failures of judgment. I employ methods of rhetorical narratology in my analysis of the novel to highlight the specifically literary ways it contributes to questions of philosophical aesthetics. This approach also accounts for the extent and types of disagreements about the novel in the critical literature about it. Within the general structure of a marriage comedy, Mansfield Park tells another story that challenges the expectations raised by that structure: the story of Fannys complicated perspective on Mansfield Park as both she and it change. I call this story the novels position plot. By complicating readers expectations for and judgments of the characters, the novel challenges readers to consider the extent to which their judgments of the characters and of the novel should be grounded in their expectations for a marriage comedy and the extent to which they should be informed by the novels portrayal of how ones position affects ones judgment. The novel manipulates readers expectations as well as their distance from the characters in clarifying the limits and possibilities of both disinterested and aesthetic judgment

Ancient evolutionary origin of vertebrate enteric neurons from trunk-derived neural crest

The enteric nervous system of jawed vertebrates arises primarily from vagal neural crest cells that migrate to the foregut and subsequently colonize and innervate the entire gastrointestinal tract. Here we examine development of the enteric nervous system in the basal jawless vertebrate the sea lamprey (Petromyzon marinus) to gain insight into its evolutionary origin. Surprisingly, we find no evidence for the existence of a vagally derived enteric neural crest population in the lamprey. Rather, labelling with the lipophilic dye DiI shows that late-migrating cells, originating from the trunk neural tube and associated with nerve fibres, differentiate into neurons within the gut wall and typhlosole. We propose that these trunk-derived neural crest cells may be homologous to Schwann cell precursors, recently shown in mammalian embryos to populate post-embryonic parasympathetic ganglia, including enteric ganglia. Our results suggest that neural-crest-derived Schwann cell precursors made an important contribution to the ancient enteric nervous system of early jawless vertebrates, a role that was largely subsumed by vagal neural crest cells in early gnathostomes

Acute increase of alpha-synuclein inhibits synaptic vesicle recycling evoked during intense stimulation

This work was supported by grants from the NIH/National Institute of Neurological Disorder and Stroke RO1 NS078165 (to J.R.M.), the Morton Cure Paralysis Fund (to J.R.M.), and the Branfman Family Foundation (to J.M.G.) and by a Dorothea Bennett graduate fellowship (to D.J.B.)

Serotoninergic modulation of sensory transmission to brainstem reticulospinal cells

Sensory inputs are subjected to modulation by central neural networks involved in controlling movements. It has been shown that serotonin (5‐HT) modulates sensory transmission. This study examines in lampreys the effects of 5‐HT on sensory transmission to brainstem reticulospinal (RS) neurons and the distribution of 5‐HT cells that innervate RS cells. Cells were recorded intracellularly in the in vitro isolated brainstem of larval lampreys. Trigeminal nerve stimulation elicited disynaptic excitatory responses in RS neurons, and bath application of 5‐HT reduced the response amplitude with maximum effect at 10 μm. Local ejection of 5‐HT either onto the RS cells or onto the relay cells decreased sensory‐evoked excitatory postsynaptic potentials (EPSPs) in RS cells. The monosynaptic EPSPs elicited from stimulation of the relay cells were also reduced by 5‐HT. The reduction was maintained after blocking either N‐methyl‐d‐aspartate (NMDA) or α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid (AMPA) receptors. The local ejection of glutamate over RS cells elicited excitatory responses that were only slightly depressed by 5‐HT. In addition, 5‐HT increased the threshold for eliciting sustained depolarizations in response to trigeminal nerve stimulation but did not prevent them. Combined 5‐HT immunofluorescence with axonal tracing revealed that the 5‐HT innervation of RS neurons of the middle rhombencephalic reticular nucleus comes mainly from neurons in the isthmic region, but also from neurons located in the pretectum and caudal rhombencephalon. Our results indicate that 5‐HT modulates sensory transmission to lamprey brainstem RS cells

Non-mammalian model systems for studying neuro-immune interactions after spinal cord injury

Mammals exhibit poor recovery after injury to the spinal cord, where the loss of neurons and neuronal connections can be functionally devastating. In contrast, it has long been appreciated that many non-mammalian vertebrate species exhibit significant spontaneous functional recovery after spinal cord injury (SCI). Identifying the biological responses that support an organism\u27s inability or ability to recover function after SCI is an important scientific and medical question. While recent advances have been made in understanding the responses to SCI in mammals, we remain without an effective clinical therapy for SCI. A comparative biological approach to understanding responses to SCI in non-mammalian vertebrates will yield important insights into mechanisms that promote recovery after SCI. Presently, mechanistic studies aimed at elucidating responses, both intrinsic and extrinsic to neurons, that result in different regenerative capacities after SCI across vertebrates are just in their early stages. There are several inhibitory mechanisms proposed to impede recovery from SCI in mammals, including reactive gliosis and scarring, myelin associated proteins, and a suboptimal immune response. One hypothesis to explain the robust regenerative capacity of several non-mammalian vertebrates is a lack of some or all of these inhibitory signals. This review presents the current knowledge of immune responses to SCI in several non-mammalian species that achieve anatomical and functional recovery after SCI. This subject is of growing interest, as studies increasingly show both beneficial and detrimental roles of the immune response following SCI in mammals. A long-term goal of biomedical research in all experimental models of SCI is to understand how to promote functional recovery after SCI in humans. Therefore, understanding immune responses to SCI in non-mammalian vertebrates that achieve functional recovery spontaneously may identify novel strategies to modulate immune responses in less regenerative species and promote recovery after SCI

Spatial Frequency-Based Analysis of Mean Red Blood Cell Speed in Single Microvessels: Investigation of Microvascular Perfusion in Rat Cerebral Cortex

BACKGROUND: Our previous study has shown that prenatal exposure to X-ray irradiation causes cerebral hypo-perfusion during the postnatal development of central nervous system (CNS). However, the source of the hypo-perfusion and its impact on the CNS development remains unclear. The present study developed an automatic analysis method to determine the mean red blood cell (RBC) speed through single microvessels imaged with two-photon microscopy in the cerebral cortex of rats prenatally exposed to X-ray irradiation (1.5 Gy). METHODOLOGY/PRINCIPAL FINDINGS: We obtained a mean RBC speed (0.9±0.6 mm/sec) that ranged from 0.2 to 4.4 mm/sec from 121 vessels in the radiation-exposed rats, which was about 40% lower than that of normal rats that were not exposed. These results were then compared with the conventional method for monitoring microvascular perfusion using the arteriovenous transit time (AVTT) determined by tracking fluorescent markers. A significant increase in the AVTT was observed in the exposed rats (1.9±0.6 sec) as compared to the age-matched non-exposed rats (1.2±0.3 sec). The results indicate that parenchyma capillary blood velocity in the exposed rats was approximately 37% lower than in non-exposed rats. CONCLUSIONS/SIGNIFICANCE: The algorithm presented is simple and robust relative to monitoring individual RBC speeds, which is superior in terms of noise tolerance and computation time. The demonstrative results show that the method developed in this study for determining the mean RBC speed in the spatial frequency domain was consistent with the conventional transit time method