bluuebunny/crossref_metadata_2025_split huggingface dataset:
Broad complex isoforms have unique distributions during central nervous system metamorphosis in Drosophila melanogaster
Authors: Spokony Rebecca F. , Restifo Linda L. 
Published: June 2009

AbstractBroad Complex (BRC) is a highly conserved, ecdysone‐pathway gene essential for metamorphosis in Drosophila melanogaster, and possibly all holometabolous insects. Alternative splicing among duplicated exons produces several BRC isoforms, each with one zinc‐finger DNA‐binding domain (Z1, Z2, Z3, or Z4), highly expressed at the onset of metamorphosis. BRC‐Z1, BRC‐Z2, and BRC‐Z3 represent distinct genetic functions (BRC complementation groups rbp, br, and 2Bc, respectively) and are required at discrete stages spanning final‐instar larva through very young pupa. We showed previously that morphogenetic movements necessary for adult CNS maturation require BRC‐Z1, ‐Z2, and ‐Z3, but not at the same time: BRC‐Z1 is required in the mid‐prepupa, BRC‐Z2 and ‐Z3 are required earlier, at the larval‐prepupal transition. To explore how BRC isoforms controlling the same morphogenesis events do so at different times, we examined their central nervous system (CNS) expression patterns during the ≈16 hours bracketing the hormone‐regulated start of metamorphosis. Each isoform had a unique pattern, with BRC‐Z3 being the most distinctive. There was some colocalization of isoform pairs, but no three‐way overlap of BRC‐Z1, ‐Z2, and ‐Z3. Instead, their most prominent expression was in glia (BRC‐Z1), neuroblasts (BRC‐Z2), or neurons (BRC‐Z3). Despite sequence similarity to BRC‐Z1, BRC‐Z4 was expressed in a unique subset of neurons. These data suggest a switch in BRC isoform choice, from BRC‐Z2 in proliferating cells to BRC‐Z1, BRC‐Z3, or BRC‐Z4 in differentiating cells. Together with isoform‐selective temporal requirements and phenotype considerations, this cell‐type‐selective expression suggests a model of BRC‐dependent CNS morphogenesis resulting from intercellular interactions, culminating in BRC‐Z1‐controlled, glia‐mediated CNS movements in late prepupa. J. Comp. Neurol. 517:15–36, 2009. © 2009 Wiley‐Liss, Inc.
Receptive field organization across multiple electrosensory maps. II. Computational analysis of the effects of receptive field size on prey localization
Authors: Maler Leonard 
Published: June 2009

AbstractThe electric fish Apteronotus leptorhynchus emits a high‐frequency electric organ discharge (EOD) sensed by specialized electroreceptors (P‐units) distributed across the fish's skin. Objects such as prey increase the amplitude of the EOD over the underlying skin and thus cause an increase in P‐unit discharge. The resulting localized intensity increase is called the electric image and is detected by its effect on the P‐unit population; the electric image peak value and the extent to its spreads are cues utilized by these fish to estimate the location and size of its prey. P‐units project topographically to three topographic maps in the electrosensory lateral line lobe (ELL): centromedial (CMS), centrolateral (CLS), and lateral (LS) segments. In a companion paper I have calculated the receptive fields (RFs) in these maps: RFs were small in CMS and very large in LS, with intermediate values in CLS. Here I use physiological data to create a simple model of the RF structure within the three ELL maps and to compute the response of these model maps to simulated prey. The Fisher information (FI) method was used to compute the optimal estimates possible for prey localization across the three maps. The FI predictions were compared with behavioral studies on prey detection. These comparisons were used to frame alternative hypotheses on the functions of the three maps and on the constraints that RF size and synaptic strength impose on weak signal detection and estimation. J. Comp. Neurol. 516:394–422, 2009. © 2009 Wiley‐Liss, Inc.
Increased expression of the growth‐associated protein 43 gene in the sensorimotor cortex of the macaque monkey after lesioning the lateral corticospinal tract
Authors: Higo Noriyuki , Nishimura Yukio , Murata Yumi , Oishi Takao , Yoshino‐Saito Kimika , Takahashi Masahito , Tsuboi Fumiharu , Isa Tadashi 
Published: June 2009

AbstractTo investigate the neural basis for functional recovery of the cerebral cortex following spinal cord injury, we measured the expression of growth‐associated protein 43 (GAP‐43), which is involved in the process of synaptic sprouting. We determined the GAP‐43 mRNA expression levels in the sensorimotor cortical areas of macaque monkeys with a unilateral lesion of the lateral corticospinal tract (l‐CST) at the C4/C5 level of the cervical cord and compared them with the levels in the corresponding regions of intact monkeys. Lesioned monkeys recovered finger dexterity during the first months after surgery, and the GAP‐43 mRNA levels increased in layers II–III in primary motor areas (M1), bilaterally. Double‐labeling analysis of the lesioned monkeys showed that GAP‐43 mRNA was expressed strongly in excitatory neurons but only rarely in inhibitory interneurons. Expression also increased in the medium‐sized (area, 500–1,000 μm2) and large pyramidal cells (area, >1,000 μm2) in layer V of the bilateral M1. The increased expression of GAP‐43 mRNA in the M1 contralateral to the lesion was more prominent during the early recovery stage than during the late recovery stage. In addition, GAP‐43 mRNA increased in layers II–III of both the contralesional ventral premotor area and the primary somatosensory area. These results suggest that GAP‐43 is involved in time‐dependent and brain region‐specific plastic changes after l‐CST lesioning. The expression patterns imply that plastic changes occur not only in M1 but also in the broad associative cortical network, including the ventral premotor and primary sensory areas. J. Comp. Neurol. 516:493–506, 2009. © 2009 Wiley‐Liss, Inc.
Compartmentalization in the triceps brachii motoneuron nucleus and its relation to muscle architecture
Authors: Lucas‐Osma Ana M. , Collazos‐Castro Jorge E. 
Published: June 2009

AbstractEach fascicle of the triceps brachii (TB) can be independently recruited during movement execution. To investigate the anatomical basis of this selective control and to gain insight into its functional role in adult rats, we carried out a triple retrograde tracing of the motoneurons (MNs) innervating each TB head, and performed muscle ATPase histochemistry and histology to correlate the size of the MN pools with the number and type of muscle fibers innervated. No double‐labeled MNs were found, demonstrating that each TB head is innervated by a completely independent MN subnucleus. Absolute cell counts determined that the long fascicle had the largest MN subnucleus, followed by the medial and the lateral fascicles. MNs of the three fascicles intermingled extensively in the rostral part of the spinal motor column, while the caudal part of the column comprised mostly MNs innervating the long fascicle. Muscle histology and average innervation ratios estimated from absolute MN counts showed that the medial head was predominantly formed by small type I fibers and motor units (69 fibers/MN). In contrast, the lateral fascicle comprised a great quantity of large type IIb fibers and motor units (179 fibers/MN), whereas the long head consisted of a more balanced mixture of fiber types and motor units (99 fibers/MN). Taking into account the mechanical and physiological heterogeneity of the TB, our findings suggest that each fascicle may be considered an independent muscle with specific functional roles. J. Comp. Neurol. 516:226–239, 2009. © 2009 Wiley‐Liss, Inc.
Receptive field organization across multiple electrosensory maps. I. Columnar organization and estimation of receptive field size
Authors: Maler Leonard 
Published: June 2009

AbstractThe electric fish Apteronotus leptorhynchus emits a high‐frequency electric organ discharge (EOD) sensed by specialized electroreceptors (P‐units). Amplitude modulations (AMs) of the EOD are caused by objects such as prey as well as by social interactions with conspecifics. The firing rate of P‐units is modulated by the AMs due to both objects and communication signals. P‐units trifurcate as they enter the medulla; they terminate topographically with three maps of the electrosensory lateral line lobe (ELL): the centromedial (CMS), centrolateral (CLS), and lateral (LS) segments. Within each map P‐units terminate onto the basal dendrites of pyramidal cells. Anterograde filling of P‐units and retrograde filling of the basal bushes of pyramidal cells were used to estimate their respective spreads and spacing in the three maps. These estimates were used to compute the receptive field structure of the pyramidal cells: receptive fields were small in CMS and very large in LS with intermediate values in CLS. There are several classes of pyramidal cells defined by morphological and functional criteria; these cells are organized into columns such that each column contains one member of each class and all cells within a column receive the same P‐unit input. J. Comp. Neurol. 516:376–393, 2009. © 2009 Wiley‐Liss, Inc.
Comparison of the spatial distribution of seven types of neuroendocrine neurons in the rat paraventricular nucleus: Toward a global 3D model
Authors: Simmons Donna M. , Swanson Larry W. 
Published: June 2009

AbstractThe paraventricular nucleus of the hypothalamus (PVH) coordinates neuroendocrine, autonomic, and behavioral responses to help maintain energy and body water balance. The rat paraventricular nucleus has three major divisions: descending with axonal projections to somatomotor‐behavioral and autonomic circuitry, magnocellular neuroendocrine with projections directly to the posterior pituitary, and parvicellular neuroendocrine with projections to the median eminence for controlling anterior pituitary hormone secretion. The present work was undertaken to provide high‐resolution mapping of spatial relationships among the two magnocellular neuroendocrine and five parvicellular neuroendocrine neuron types throughout the nucleus. Double immunohistochemical labeling for two neuron types combined with retrograde labeling to identify neuroendocrine neurons positively was used in individual sections spaced 45 μm apart, along with a grid transfer method for reducing plane of section artifacts when comparing staining pattern data between animals. The results indicate that whereas each neuroendocrine neuron phenotype displays a unique distribution pattern, there is extensive partial overlap in a complex pattern between small “hot spots” with a relatively high density of a particular neuron type and few if any other phenotypes. In addition, the distribution of non‐neuroendocrine neurons staining with each of the markers (but not retrogradely labeled) was mapped and compared with each other and with the neuroendocrine neuron populations. This spatial organization raises important questions about the differential functional regulation of individual—and perhaps sets of—neuroendocrine motor neuron populations in the PVH by synaptic mechanisms and by less traditional mechanisms like dendritic neurotransmitter release and gap junctions within and between neuron types. J. Comp. Neurol. 516:423–441, 2009. © 2009 Wiley‐Liss, Inc.
Associative pairing involving monocular stimulation selectively mobilizes a subclass of GABAergic interneurons in the mouse visual cortex
Authors: Liguz‐Lecznar Monika , Waleszczyk Wioletta J. , Zakrzewska Renata , Skangiel‐Kramska Jolanta , Kossut Malgorzata 
Published: June 2009

AbstractLevels of γ‐aminobutyric acid (GABA) and its synthesizing enzyme in cerebral cortex are regulated by sensory experience. Previously we found that associative pairing of vibrissae stimulation and tail shock results in upregulation of GABAergic markers in the mouse barrel cortex. In order to ascertain whether GABAergic upregulation also accompanies associative pairing in other sensory modalities, we examined the mouse visual cortex after analogous training with visual stimulus. During pairing, visual stimulus (CS) was coupled with a tail shock (UCS). We examined the density of cells expressing glutamic acid decarboxylase (GAD) and parvalbumin (PV) in monocular and binocular segments of the primary visual cortex (V1). The auditory cortex was used as a control. After monocular training, the density of cells expressing GAD rose significantly in the monocular segment of V1 contralateral to the stimulated eye, compared with the opposite hemisphere. This effect was due to the association of CS and UCS, as no changes were found after visual stimulation alone or in the auditory cortex. No changes were noted in the density of PV+ neurons, so the effect was attributed to GAD+/PV− neurons. Mobilization of a specific subclass of GABAergic cells, observed after associative pairing in the somatosensory and visual cortices, may reflect the necessity to restrict the activity of circuits involved in sensory association. J. Comp. Neurol. 516:482–492, 2009. © 2009 Wiley‐Liss, Inc.
Enkephalins, dynorphins, and β‐endorphin in the rat dorsal horn: An immunofluorescence colocalization study
Authors: Marvizón Juan Carlos G. , Chen Wenling , Murphy Niall 
Published: June 2009

AbstractTo characterize neuronal pathways that release opioid peptides in the rat dorsal horn, multiple‐label immunohistochemistry, confocal microscopy, and computerized co‐localization measures were used to characterize opioid‐containing terminals and cells. An antibody that selectively recognized β‐endorphin labeled fibers and neurons in the ventral horn as well as fibers in the lateral funiculus and lamina X, but practically no fibers in the dorsal horn. An anti‐enkephalin antibody, which recognized Leu‐, Met‐, and Phe‐Arg‐Met‐enkephalin, labeled the dorsolateral funiculus and numerous puncta in laminae I–III and V of the dorsal horn. An antibody against Phe‐Arg‐Met‐enkephalin, which did not recognize Leu‐ and Met‐enkephalin, labeled the same puncta. Antibodies against dynorphin and prodynorphin labeled puncta and fibers in laminae I, II, and V, as well as some fibers in the rest of the dorsal horn. Dynorphin and prodynorphin immunoreactivities colocalized in some puncta and fibers, but the prodynorphin antibody additionally labeled cell bodies. There was no co‐localization of dynorphin (or prodynorphin) with enkephalin (or Phe‐Arg‐Met‐enkephalin). Enkephalin immunoreactivity did not colocalize with the C‐fiber markers calcitonin gene‐related peptide (CGRP), substance P, and isolectin B4. In contrast, there was some colocalization of dynorphin and prodynorphin with CGRP and substance P, but not with isolectin B4. Both enkephalin and dynorphin partly colocalized with vesicular glutamate transporter 2, a marker of glutamatergic terminals. The prodynorphin‐positive neurons in the dorsal horn were distinct from neurons expressing μ‐opioid receptors, neurokinin 1 receptors, and protein kinase C‐γ. These results show that enkephalins and dynorphins are present in different populations of dorsal horn neurons. In addition, dynorphin is present in some C‐fibers. J. Comp. Neurol. 517:51–68, 2009. Published 2009 Wiley‐Liss, Inc.
Viral strategies for studying the brain, including a replication‐restricted self‐amplifying delta‐G vesicular stomatis virus that rapidly expresses transgenes in brain and can generate a multicolor golgi‐like expression
Authors: van den Pol Anthony N. , Ozduman Koray , Wollmann Guido , Ho Winson S.C. , Simon Ian , Yao Yang , Rose John K. , Ghosh Prabhat 
Published: June 2009

AbstractViruses have substantial value as vehicles for transporting transgenes into neurons. Each virus has its own set of attributes for addressing neuroscience‐related questions. Here we review some of the advantages and limitations of herpes, pseudorabies, rabies, adeno‐associated, lentivirus, and others to study the brain. We then explore a novel recombinant vesicular stomatitis virus (dG‐VSV) with the G‐gene deleted and transgenes engineered into the first position of the RNA genome, which replicates only in the first brain cell infected, as corroborated with ultrastructural analysis, eliminating spread of virus. Because of its ability to replicate rapidly and to express multiple mRNA copies and additional templates for more copies, reporter gene expression is amplified substantially, over 500‐fold in 6 hours, allowing detailed imaging of dendrites, dendritic spines, axons, and axon terminal fields within a few hours to a few days after inoculation. Green fluorescent protein (GFP) expression is first detected within 1 hour of inoculation. The virus generates a Golgi‐like appearance in all neurons or glia of regions of the brain tested. Whole‐cell patch‐clamp electrophysiology, calcium digital imaging with fura‐2, and time‐lapse digital imaging showed that neurons appeared physiologically normal after expressing viral transgenes. The virus has a wide range of species applicability, including mouse, rat, hamster, human, and Drosophila cells. By using dG‐VSV, we show efferent projections from the suprachiasmatic nucleus terminating in the periventricular region immediately dorsal to the nucleus. DG‐VSVs with genes coding for different color reporters allow multicolor visualization of neurons wherever applied. J. Comp. Neurol. 516:456–481, 2009. © 2009 Wiley‐Liss, Inc.
Arcuate nucleus expression of NKX2.1 and DLX and lineages expressing these transcription factors in neuropeptide Y+, proopiomelanocortin+, and tyrosine hydroxylase+ neurons in neonatal and adult mice
Authors: Yee Cindy L. , Wang Yanling , Anderson Stewart , Ekker Marc , Rubenstein John L.R. 
Published: June 2009

AbstractDespite its small size, the arcuate nucleus of the hypothalamus has a critical role in regulating energy homeostasis. We have begun to define genetic approaches to express genes in specific cell types within the developing arcuate nucleus, to allow precise molecular perturbations of these cells. Furthermore, our analysis aims to contribute to defining the transcriptional networks that regulate the development of function of the arcuate neurons. Here, we define the neuronal cells types within the arcuate that express Nkx2.1 and Dlx homeobox genes. In addition, we used mice expressing Cre recombinase from the Dlx5/6 intergenic enhancer (Dlx5/6i) and from the Nkx2.1 locus to follow the fate of embryonic cells expressing these genes within the arcuate nucleus. We demonstrate that NKX2.1+ cells and their lineages are broadly expressed in arcuate neurons [γ‐aminobutyric acid (GABA)+, neuropeptide Y (NPY)+, proopiomelanocortin (POMC)+, tyrosine hydroxylase (TH)+] and glia (tanycytes). On the other hand, DLX+ cells and their lineages mark only GABA+ and TH+ (dopaminergic) neurons, and Dlx1–/– mutants have fewer TH+ neurons. These results have implications for the genetic control of arcuate development and function and for the utility of the Nkx2.1‐Cre and Dlx5/6i‐Cre mouse lines to alter gene expression in the developing arcuate. J. Comp. Neurol. 517:37–50, 2009. © 2009 Wiley‐Liss, Inc.
The proportion of synapses formed by the axons of the lateral geniculate nucleus in layer 4 of area 17 of the cat
Authors: da Costa Nuno Maçarico , Martin Kevan A.C. 
Published: June 2009

AbstractThe connection between the dorsal lateral geniculate nucleus (dLGN) and area 17 of the cat is a classical model for studying thalamocortical relations. We investigated the proportion of asymmetric synapses in layer 4 of area 17 of cats formed by axons of the dLGN, because this is an important morphological parameter in understanding the impact of dLGN axons on their target neurons. Although the present consensus is that this proportion is small, the exact percentage remains in doubt. Most previous work estimated that the thalamus contributes less than 10% of excitatory synapses in layer 4, but one estimate was as high as 28%. Two issues contribute to these widely different estimates, one being the tracers used, the other being the use of biased stereological approaches. We have addressed both of these issues. Thalamic axons were labeled in vivo by injections of biotinylated dextran amine into the A lamina of the dLGN of anesthetized cats. After processing, the brain was cut serially and prepared for light and electron microscopy. The density of asymmetric synapses in the neuropil and the density of synapses formed by labeled dLGN boutons were measured by using an unbiased sampling method called the physical disector. Our counts indicate that, in the fixed cat brain, there are 5.9 × 108 ± 0.9 × 108 asymmetric synapses per cubic millimeter of layer 4 in area 17, and the dLGN input provides only 6% of all asymmetric synapses in layer 4. The vast majority of synapses of layer 4 probably originate from other neurons in area 17. J. Comp. Neurol. 516:264–276, 2009. © 2009 Wiley‐Liss, Inc.
Specificity of the horizontal cell‐photoreceptor connections in the zebrafish (Danio rerio) retina
Authors: Li Yong N. , Matsui Jonathan I. , Dowling John E. 
Published: June 2009

AbstractHorizontal cells (HCs) are involved in establishing the center‐surround receptive field organization of photoreceptor and bipolar cells. In many species, HCs respond differentially to colors and may play a role in color vision. An earlier study from our laboratory suggested that four types of HCs exist in the zebrafish retina: three cone HCs (H1, H2 and H3) and one rod HC. In this study, we describe their photoreceptor connections. Cones are arranged in a mosaic in which rows of alternating blue (B)‐ and ultraviolet (UV)‐sensitive single cones alternate with rows of red (R)‐ and green (G)‐sensitive double cones; the G cones are adjacent to UV cones and B cones adjacent to R cones. Two small‐field (H1 and H2) and two large‐field (H3 and rod HC) cells were observed. The cone HC dendritic terminals connected to cones with single boutons, doublets, or rosettes, whereas the rod HCs connected to rods with single boutons. The single boutons/doublets/rosettes of cone HCs were arranged in double rows separated by single rows for H1 cells, in pairs and singles for H2 cells, and in a rectilinear pattern for H3 cells. These connectivity patterns suggest that H1 cells contact R, G, and B cones, H2 cells G, B, and UV cones, and H3 cells B and UV cones. These predictions were confirmed by applying the DiI method to SWS1‐GFP retinas whose UV cones express green fluorescent protein. Each rod HC was adjacent to the soma or axon of a DiI‐labeled cone HC and connected to 50–200 rods. J. Comp. Neurol. 516:442–453, 2009. © 2009 Wiley‐Liss, Inc.