The parabrachial nucleus (PB) is a brainstem cell group that receives a strong input from the nucleus tractus solitarius regarding the physiological status of the internal organs and sends efferent projections throughout the forebrain. Since the neuroanatomical organization of the PB remains unclear, our first step was to use specific antibodies against two neural lineage transcription factors: Forkhead box protein2 (FoxP2) and LIM homeodomain transcription factor 1 beta (Lmx1b) to define the PB in adult rats. This allowed us to construct a cytoarchitectonic PB map based on the distribution of neurons that constitutively express these two transcription factors. Second, the in situ hybridization method combined with immunohistochemistry demonstrated that mRNA for glutamate vesicular transporter Vglut2 (Slc17a6) was present in most of the Lmx1b+ and FoxP2+ parabrachial neurons, indicating these neurons use glutamate as a transmitter. Third, conscious rats were maintained in a hypotensive or hypertensive state for two hours, and then, their brainstems were prepared by the standard c-Fos method which is a measure of neuronal activity. Both hypotension and hypertension resulted in c-Fos activation of Lmx1b+ neurons in the external lateral-outer subdivision of the PB (PBel-outer). Hypotension, but not hypertension, caused c-Fos activity in the FoxP2+ neurons of the central lateral PB (PBcl) subnucleus. The Kölliker-Fuse nucleus as well as the lateral crescent PB and rostralmost part of the PBcl contain neurons that co-express FoxP2+ and Lmx1b+, but none of these were activated after blood pressure changes. Salt-sensitive FoxP2 neurons in the pre-locus coeruleus and PBel-inner were not c-Fos activated following blood pressure changes. In summary, the present study shows that the PBel-outer and PBcl subnuclei originate from two different neural progenitors, contain glutamatergic neurons, and are affected by blood pressure changes, with the PBel-outer reacting to both hypo- and hypertension, and the PBcl signaling only hypotensive changes.

The sensory circumventricular organs (CVOs) are specialized collections of neurons and glia that lie in the midline of the third and fourth ventricles of the brain, lack a blood-brain barrier, and function as chemosensors, sampling both the cerebrospinal fluid and plasma. These structures, which include the organum vasculosum of the lamina terminalis (OVLT), subfornical organ (SFO), and area postrema (AP), are sensitive to changes in sodium concentration but the cellular mechanisms involved remain unknown. Epithelial sodium channel (ENaC)-expressing neurons of the CVOs may be involved in this process. Here we demonstrate with immunohistochemical and in situ hybridization methods that ENaC-expressing neurons are densely concentrated in the sensory CVOs. These neurons become c-Fos activated, a marker for neuronal activity, after various manipulations of peripheral levels of sodium including systemic injections with hypertonic saline, dietary sodium deprivation, and sodium repletion after prolonged sodium deprivation. The increases seen c-Fos activity in the CVOs were correlated with parallel increases in plasma sodium levels. Since ENaCs play a central role in sodium reabsorption in kidney and other epithelia, we present a hypothesis here suggesting that these channels may also serve a related function in the CVOs. ENaCs could be a significant factor in modulating CVO neuronal activity by controlling the magnitude of sodium permeability in neurons. Hence, some of the same circulating hormones controlling ENaC expression in kidney, such as angiotensin II and atrial natriuretic peptide, may coordinate ENaC expression in sensory CVO neurons and could potentially orchestrate sodium appetite, osmoregulation, and vasomotor sympathetic drive.

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The connection between reading and writing seems straightforward: if there is writing, then someone must be able to read it. In art history, the act of 'reading' an image, a mainstay in a number of its methods, is connected to questions of close looking: when, for example, does close looking give way to close reading and vice versa, or, is it possible to simultaneously look and read closely? Prior to viewers being able to read or see anything -words or images -someone must have made the things that are read and seen. To the extent that writing is defined by its ability to be read, it must first be recognizable as readable. Just as writing can be closely read, it must also be closely seen, and it must have been designed to be readable. This article is an exercise in close looking at writing. It argues that, on the one hand, this particular way of seeing writing up close requires knowing how writing is made, not simply the structure of the particular writing system in question, but also, more literally, the material processes that underlie its production. On the other hand, to closely read requires a certain distance from the writing, so that these techniques of making writing are secondary concerns (if they are concerns at all) and thus do not interfere with the readability, as it were, of the text. Yet, at a certain viewing distance (perhaps close but not too close), the legibility of writing meets its readability. It is at these varying distances of seeing, I suggest in this essay, that ambiguity between words and images may be found.The type of writing examined in this article is woven inscriptions in Chinese characters (zhiwen) dated to the Eastern Han dynasty (25-220 CE) and possibly produced as late as the Jin (265-420 CE) that were excavated in the modern-day Xinjiang Uyghur Autonomous Region in China. These woven inscriptions do not necessarily have to be read in order to convey their messages. The content they record -repetitive blessings of longevity and descendants that appear in one form or another on numerous other precious and everyday objects in early China -is not only formulaic, but is also reinforced by the iconography of the decorative programme that accompanies them. Even if we could not read the inscriptions, we could 'read' the images of various mythical creatures and cloud swirls to similar effect. 1 Moreover, these textiles with woven inscriptions were excavated far from the early imperial Chinese court, in places such as the Western Regions (xiyu) where the Chinese writing system would not have been used as the primary form of written communication. 2 For these reasons among others, Lothar von Falkenhausen, in his examination of two textile fragments that contain Chinese inscriptions found in the Syrian oasis city of Palmyra, suggests that '[o]ne may thus speak of an iconic use of writing, in which

The effect of masker spatial variability and masker fringe on the perception of a brief tone in noise was investigated in a detection task. Simpson (2011) found large effects of spatial variability (randomizing masker locations from trial to trial) in a masked localization experiment, as well as two effects of masker fringe (masking noise before the onset of the target): 1) cuing the masker location (spatial cuing effect) and 2) temporally separating the onset of the masker and the onset of the target (onset effect). In contrast, in detection studies, the effects of masker spatial variability are small (e.g., Bernstein & Trahiotis, 1997) and the possibility of a spatial cuing effect has not been directly examined. However, onset effects of similar magnitude to those observed by Simpson have been reported (e.g., McFadden, 1966). To determine whether these differences in the effect of masker variability between localization and detection could be attributed to the fact that in localization experiments there is also trial-to-trial variability in the target, we conducted a detection experiment via headphones using a 2 Masker Variability (variable & fixed) x 2 Target Variability (variable & fixed) x 2 Masker Fringe (no fringe & fringe) factorial design. We used a 60-ms, 500-Hz sinusoidal target and a 60-ms Gaussian noise masker (and a 500-ms Gaussian noise masker fringe in the fringe conditions). Masker and/or target location was varied laterally by varying the interaural