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C1 catecholamine neurons reside within the rostroventrolateral medulla (RVLM), an area that plays an integral role in blood pressure regulation through reticulospinal projections to sympathetic preganglionic neurons in the thoracic spinal cord. In a previous investigation we mapped the efferent projections of C1 neurons, documenting supraspinal projections to cell groups in the preautonomic network that contribute to the control of cardiovascular function. Light microscopic study also revealed putative local circuit connections within RVLM. In this investigation we tested the hypothesis that RVLM C1 neurons elaborate a local circuit synaptic network that permits communication between C1 neurons giving rise to supraspinal and reticulospinal projections. A replication defective lentivirus vector that expresses enhanced green fluorescent protein (EGFP) under the control of a synthetic dopamine beta hydroxylase (DβH) promoter was used to label C1 neurons and their processes. Confocal fluorescence microscopy demonstrated thin varicose axons immunopositive for EGFP and tyrosine hydroxylase that formed close appositions to C1 somata and dendrites throughout the rostrocaudal extent of the C1 area. Dual-labeled electron microscopic analysis revealed axosomatic, axodendritic and axospinous synaptic contacts with C1 and non-C1 neurons with a distribution recapitulating that observed in the light microscopic analysis. Labeled boutons were large, contained light axoplasm, lucent spherical vesicles, and formed asymmetric synaptic contacts. Collectively these data demonstrate that C1 neurons form a synaptic network within the C1 area that may function to coordinate activity among projection-specific subpopulations of neurons. The data also suggest that the boundaries of RVLM should be defined on the basis of function criteria rather than the C1 phenotype of neurons.

The sympathetic innervation of lumbar dorsal root ganglia (DRGs) and the possible presence of spinal cord circuits connecting primary sensory afferents to the sympathetic outflow to DRGs were investigated. We used simultaneous tracing of the sympathetic input to and sensory output from DRGs. Adult male rats received unilateral microinjections of the Bartha strain of pseudorabies virus into four lumbar DRGs. At 24 h post-inoculation, productive infection was detected in both DRG neurons and sympathetic postganglionic neurons. Infection of spinal cord neurons was first observed in sympathetic preganglionic neurons of the intermediolateral column. Subsequently, the infection spread to the contralateral intermediolateral column, the area around the central canal and the superficial dorsal horn layers. To investigate the relationship between infected spinal cord neurons and primary afferents from the corresponding DRGs, we injected pseudorabies virus for retrograde tracing together with cholera toxin B for anterograde tracing. We found that infected LIV/LV and LX neurons were in close apposition to cholera toxin B labeled afferents. Importantly, immunohistochemical detection of bassoon, a pre-synaptic zone protein, identified such contacts as synapses. Together, this suggests synaptic contacts between primary sensory afferents and neurons regulating sympathetic outflow to corresponding DRGs.

This paper describes a generic dynamic control system designed for use in semiconductor fabrication process control. The controller is designed for any batch silicon wafer process that is run on equipment having a high number of variables that are under operator control. These controlled variables include both equipment state variables such as power, temperature, etc., and the repair, replacement, or maintenance of equipment parts, which cause parameter drift of the machine over time. The controller consists of three principal components: 1) an automatically updating database, 2) a neural-network prediction model for the prediction of process quality based on both equipment state variables and parts usage, and 3) an optimization algorithm designed to determine the optimal change of controllable inputs that yield a reduced operation cost, in-control solution. The optimizer suggests a set of least cost and least effort alternatives for the equipment engineer or operator. The controller is a PC-driven software solution that resides outside the equipment and does not mandate implementation of recommendations in order to function correctly. The neural model base continues to learn and improve over time. An example of the dynamic process control tool performance is presented retrospectively for a plasma etch system. In this study, the neural networks exhibited overall accuracy to within 20% of the observed values of .986, .938, and .87 for the output quality variables of etch rate, standard deviation, and selectivity, respectively, based on a total sample size of 148 records. The control unit was able to accurately detect the need for parts replacements and wet clean operations in 34 of 40 operations. The controller suggested chamber state variable changes which either improved performance of the output quality variables or adjusted the input variable to a lower cost level without impairment of output quality.

This paper details the use of neural network technologies in the characterization of bit fail patterns occurring on SRAM chips as an alternative to the more traditional rule-based or knowledge-based approach to fail-pattern occurrence and classification analysis. The results of bit fail pattern count analyses are used both for fault analysis post-processing and manufacturing yield improvement methodologies. The move toward neural network implementation comes in response to prohibitively long processing times required for implementation of rule-based algorithms on more complex devices and the added flexibility of a neural network to learn new fail types in a more adaptive mode. An unsupervised approach to fail pattern identification was implemented on a 128 K SRAM chip using a two-layer Kohonen Self Organizing Map for identification and concurrence of bit fail pattern categories within SRAM chips. A second network utilized a multilayer perceptron (MLP) architecture with backpropagation of error for prediction of the number of occurrences per bitmap of each of the 34 previously identified shape types. The MLP used the output of a SOM as its input vector to assist in the feature extraction by shape type. Both trained networks out-performed existing rule-based algorithms both in ability to identify bit fail pattern types, frequency counts, and speed of processing. >

The hypothalamus is a small but influential subdivision of the diencephalon essential for adaptive changes in physiology, maintenance of homeostasis, and reproduction of species. These functions are achieved through regulatory influences over central pattern generators, central preautonomic networks, and neuroendocrine control over pituitary secretion. This article reviews the functional architecture of the hypothalamus that permits the hypothalamus to integrate sensory input in support of coordinated adaptive changes in physiology and behavior.

Neurons containing phenylethanolamine-N-methyltransferase and the other enzymes required for epinephrine synthesis exist in three clusters in the mammalian brain stem. These ‘adrenergic neurons’ appear to be functionally involved in regulation of the sympathetic nervous system and the integration of autonomic, behavioral, and endocrine responses. While typically thought of as adrenergic neurons, evidence exists to question whether these neurons utilize epinephrine as a signaling molecule.

Bleomycin hydrolase is a multifaceted neutral cysteine protease with a suggested role in antigen presentation, homocysteine-thiolactone metabolism, and Alzheimer’s disease pathogenesis. Deletion of the protease in mice results in increased neonatal mortality and dermatopathology. Immunohistochemical and behavioral studies of BLMH knockout mice were undertaken to further evaluate the role of the protease in the brain. No gross abnormalities in the central nervous system were observed upon preliminary histological examination of B6.129Blmhtm1Geh/J null animals. However, glial fibrillary acid protein immunohistochemistry revealed a global reactive astrogliosis in the aged null animals, indicative of undefined brain pathology. The role of BLMH in the brain was further explored by characterizing the behavioral phenotype of hybrid [129S6-Blmhtm1Geh/J X B6.129 Blmhtm1Geh/J]F1 null and littermate controls using multiple behavioral paradigms. In the water maze, deletion of BLMH resulted in poorer performance during water maze probe trials without detectable effect of the mutation on sensorimotor function. In addition, no age-dependent decline in discriminative performance on probe trials was observed in null animals. These data suggest a physiological non-redundant function for BLMH in the central nervous system.

This paper details an advanced set of analyses designed to drive specific process variable setpoint adjustments or maintenance actions required for cost effective process control using the Dynamic Neural Controller/spl trade/ (DNC) wafer-to-wafer advisories for semiconductor manufacturing advanced process control. The new analytic displays and metrics are illustrated using data obtained on a LAM 4520XL at STMicroelectronics as part of a SEMATECH SPIT beta test evaluation. The DNC represents a comprehensive modeling environment that uses as its input extensive process chamber information and history of the time since maintenance actions occurred. The DNC uses a neural network to predict multiple quality output metrics and a closed-loop risk-based optimization to maximize process quality performance while minimizing overall cost of tool operation and machine downtime. The software responds in an advisory mode on a wafer-to-wafer basis as to the optimal actions to be taken. In this paper, we present three specific instances of patterns arising during wafer processing over time that signal the process or equipment engineer to the need for corrective action: either a process setpoint adjustment or specific maintenance actions. Based on the controller's recommended corrective action set with the overall risk reduction predicted by such actions, a metric of corrective action "urgency" can be created. The tracking of this metric over time yields different pattern types that signify a quantified need for a specific type of corrective action. Three basic urgency patterns are found: 1. a pattern in a given maintenance action over time showing increasing urgency or "risk reduction" capability for the action; 2. a pattern in a process variable specific to a given recipe indicating a chronic request over time to only adjust the variable setpoint either above or below the current target; 3. a pattern in a process variable existing over all recipes processed through the chamber indicating chronic request to adjust the variable setpoint in either or both directions over time. This pattern is a pointer to the need for a maintenance action that is either corroborated by the urgency graph for that maintenance action, or if no such action has been previously taken, a guide to the source of the equipment malfunction.

Previous studies have shown that neurons in addition to those in the medullary respiratory groups are involved in activating phrenic motoneurons during a number of behaviors, including vomiting and reaction to vestibular stimulation. However, the location of premotor inspiratory neurons outside of the main medullary respiratory groups is largely unknown, particularly in emetic species. In the present study, the transneuronal tracer pseudorabies virus was injected into the diaphragm of the ferret, and the locations of retrogradely-labeled motoneurons and transneuronally-labeled pre-motoneurons in the brainstem and cervical and thoracic spinal cord were mapped. Injections of a monosynaptic tracer, cholera toxin, were also made in order to verify the location of motoneurons innervating the diaphragm. Phrenic motoneurons identified with pseudorabies virus and cholera toxin were confined largely to the C5-C7 levels of spinal cord, and often gave rise to prominent polarized dendritic arbors that extended across the midline. At post-inoculation survival times > or = three days, transneuronally-labeled interneurons were located in the cervical and thoracic spinal cord and portions of the brainstem, including the midline pontomedullary reticular formation and the lateral medullary reticular formation. Double-labeling studies revealed that although the infected midline neurons were located in the proximity of serotonergic neurons, only a small number of the virus-containing cells were positive for serotonin. These findings suggest that neurons in the midline of the medulla and pons influence the activity of phrenic motoneurons, perhaps during inspiratory behaviors unique to emetic animals (such as vomiting).

This paper presents results and commentary on using a cascade neural network and a policy-iteration optimization routine to provide suggested process setpoints for recovery from long-term machine drift in a LAM 4520 6-in dielectric etcher. Traditional plasma etch variables such as pressures, gas flows, temperatures, RF power, etc, are combined with a generalized representation of the time dependent effects of maintenance events to predict film etch rates, uniformity, and selectivity, A cascade neural-network model is developed using 15 months of data divided into train, test, and validation sets. The neural model both fits the validation data well and captures the nonuniformity in the in-control region of the machine. Two control algorithms use this model in a predictive configuration to identify input state changes, including maintenance events, to bring an out-of-control situation back into control. The overall goal of the optimization is to reduce equipment downtime and decrease cost of ownership of the tool by speeding up response time and extending the lifetime of consumable parts. The optimization routines were tested on 11 out-of-control situations and successfully suggested reasonable low-cost solutions to each for bringing the system back into control.

Pseudorabies virus was injected into the wall of the urinary bladder and, following incubation times of 2, 3 and 4 days, central nervous tissue was processed immunohistochemically for the presence of virus. Longer incubation times resulted in more extensive spread of the virus. Infected neurons were initially found in the spinal cord (mainly lumbosacral) and, after longer survival times, in raphe nuclei, reticular area, pontine micturition center, locus coeruleus, red nucleus, hypothalamus, preoptic, and cortical areas. These data define a multisynaptic circuit of neurons whose ultimate output influences urinary bladder function.

The effect of sustained activation of excitatory amino acid receptors on neuronal survival was studied using slices of adult rat hippocampus and light and electron microscopy. Kainate, N-methyl- d -aspartate , quisqualate, and ibotenate all produce signs of severe neurotoxicity within 90 min. Neuronal damage occurs in the form of perikaryal and dendritic swelling, cytoplasmic and nucleoplasmic disintegration, and plasma and nuclear membrane ruffling and collapse. The toxicity is restricted to intrinsic neuronal somata, dendrites and spines, while afferent axons, boutons and glia are spared. Although damage is generally distributed throughout all areas of hippocampus, kainate has little effect on pyramidal neurons in the CA2 region. Quantitative analysis of neuronal survival indicates that agonists induce dose-dependent damage over concentration ranges known to be excitatory. Based on selective antagonism by dl -aminophosphonoheptanoate and the patterns of damage produced by each, N-methyl- d -aspartate , kainate, and quisqualate trigger neurotoxicity by acting on distinct receptor classes. It is concluded that, in hippocampal slices, excitatory amino acids induce neurotoxicity in a similar manner to their actions in vivo . The results support the hypothesis that hippocampal neurotoxicity is initiated by excessive excitation, and provide another example of the capacity of adult hippocampal neurons for rapid structural modification.

The distribution of vasopressin-, vasoactive intestinal polypeptide-, somatostatin-, avian pancreatic polypeptide-, 5-hydroxytryptamine- and glutamic acid decarboxylase-like immunoreactivity was analyzed in the suprachiasmatic nuclei of male and female golden hamsters. Vasopressin. Vasopressin-like immunoreactivity is localized within neurons, dendrites and axons throughout the rostrocaudal extent of the suprachiasmatic nuclei. Immunoreactive perikarya are restricted to the dorsomedial aspect of each nucleus and occur in highest numbers within the intermediate two-thirds of the rostrocaudal axis. Axons containing vasopressin-like immunoreactivity form a dense plexus in the dorsomedial suprachiasmatic nuclei and in a vertical column at the lateral aspect of each nucleus. Somatostatin. Somatostatin-like immunoreactivity is also contained in neurons in the dorsomedial aspect of the suprachiasmatic nuclei and in thin varicose axons distributed throughout the suprachiasmatic nuclei in a pattern similar to that of vasopressin-immunoreactive axons. Vasoactive intestinal polypeptide. Vasoactive intestinal polypeptide-immunoreactive neurons are concentrated in the ventrolateral portion of each nucleus and occur almost exclusively within the intermediate two-thirds of the rostrocaudal axis. An extremely dense plexus of varicose axons exhibiting vasoactive intestinal polypeptide-like immunoreactivity extends throughout the suprachiasmatic nuclei and passes out of the dorsal aspect of each nucleus into the periventricular and anterior hypothalamic areas. Avian pancreatic polypeptide. Avian pancreatic polypeptide-like immunoreactivity is restricted to axons which arborize within the ventrolateral aspect of each nucleus. These fibers extend throughout the rostrocaudal extent of each nucleus and partially overlap the terminal field of retinal afferents. Glutamic acid decarboxylase. A very dense plexus of axonal varicosities exhibiting glutamic acid decarboxylase-like immunoreactivity fills both the dorsomedial and ventrolateral portions of the suprachiasmatic nuclei throughout the rostrocaudal extent of each nucleus. Lightly stained immunoreactive perikarya also occur throughout the suprachiasmatic nuclei. 5-Hydroxytryptamine. 5-Hydroxytryptamine-like immunoreactivity is restricted to axons which form a plexus in the ventromedial portion of each nucleus that is most dense in the intermediate two-thirds of the rostrocaudal axis.(ABSTRACT TRUNCATED AT 400 WORDS)