Development Of Topographic Maps Research Articles

Tasks and challenges of the Head Office of Geodesy and Cartography in the area of developing topographic maps in 1:25,000 scale

Abstract. In accordance with the legal regulations in force in Poland in the field of cartography, i.e. the Geodetic and Cartographic Law, one of the tasks of the Chief National Surveyor is to create and provide access to topographic, general geographic, thematic and special maps. Moreover, the topographic maps are developed in close cooperation with the Minister of National Defense. The basis for the development of topographic maps is, in particular, the Topographic Objects Database BDOT10k with the topographic objects’ level of details corresponding to 1:10,000 scale, the National Register of Geographic Names and the Digital Terrain Model.Considering the above, in 2022, the Head Office of Geodesy and Cartography, as part of its own work, launched a pilot project aimed at developing tools to automatically generate topographic maps in 1:10,000 and 1:25,000 scale. At a current stage, as part of the II iteration, the maps do not yet constitute full-fledged topographic maps, but we are striving for such a goal. The tools are constantly developed and corrections are made to eliminate errors that still occur. The maps in 1:10,000 and 1:25,000 scales, developed so far under this project in a fully automatic manner, are available free of charge to all interested users on the www.geoportal.gov.pl website.In the article, the results of the developed tools and generated topographic maps 1:25,000 will be presented, as well as the problems faced both in the context of the methodology and the limitations resulting from the software used.

Analysis of Activity Dependent Development of Topographic Maps in Neural Field Theory with Short Time Scale Dependent Plasticity

Topographic maps are a brain structure connecting pre-synpatic and post-synaptic brain regions. Topographic development is dependent on Hebbian-based plasticity mechanisms working in conjunction with spontaneous patterns of neural activity generated in the pre-synaptic regions. Studies performed in mouse have shown that these spontaneous patterns can exhibit complex spatial-temporal structures which existing models cannot incorporate. Neural field theories are appropriate modelling paradigms for topographic systems due to the dense nature of the connections between regions and can be augmented with a plasticity rule general enough to capture complex time-varying structures. We propose a theoretical framework for studying the development of topography in the context of complex spatial-temporal activity fed-forward from the pre-synaptic to post-synaptic regions. Analysis of the model leads to an analytic solution corroborating the conclusion that activity can drive the refinement of topographic projections. The analysis also suggests that biological noise is used in the development of topography to stabilise the dynamics. MCMC simulations are used to analyse and understand the differences in topographic refinement between wild-type and the $\beta2$ knock-out mutant in mice. The time scale of the synaptic plasticity window is estimated as $0.56$ seconds in this context with a model fit of $R^2 = 0.81$.

Vagus Topographic Map: Wandering through a gRAdient.

Topographic map development requires precise coordination between navigating axons and their targets in a dynamic environment. In this issue of Developmental Cell, Isabella etal. describe a mechanism in which a changing gradient of the morphogen retinoic acid regulates the expression of guidance factors to shape topographic axon targeting.

Retinoic Acid Organizes the Zebrafish Vagus Motor Topographic Map via Spatiotemporal Coordination of Hgf/Met Signaling.

Information flow through neural circuits often requires their organization into topographic maps in which the positions of cell bodies and synaptic targets correspond. To understand how topographic map development is controlled, we examine the mechanism underlying targeting of vagus motor axons to the pharyngeal arches in zebrafish. We reveal that retinoic acid organizes topography by specifying anterior-posterior identity in vagus motor neurons. We then show that chemoattractant signaling between Hgf and Met is required for vagus innervation of the pharyngeal arches. Finally, we find that retinoic acid controls the spatiotemporal dynamics of Hgf/Met signaling to coordinate axon targeting with the developmental progression of the pharyngeal arches and show that experimentally altering the timing of Hgf/Met signaling is sufficient to redirect axon targeting and disrupt the topographic map. These findings establish a mechanism of topographic map development in which the regulation of chemoattractant signaling in space and time guides axon targeting.

ЗАСТОСУВАННЯ КАРТОСЕМІОТИЧНИХ ПОЛОЖЕНЬ КАРТОГРАФІЧНОГО МОДЕЛЮВАННЯ

The article is devoted to considering the methodology of harmonizing the parameters and elements of the contents of thedomestic topographical map of the scale of 1:500,000 with a map of the same scale, developed in accordance with NATOstandards (TPC, ONC). It provides for analysis, with the possible reciprocal use of existing Samples of "Maps of Common Action"(Joint operations graphic - JOG, Series 1501) scale 1: 250,000 as a quadruple-sheet map of a scale of 1:500,000. The methodologypresents the result of graphic language studies in the general theory of iconic systems as language formations and subsequentscientific developments, which are implemented on the basis of the theoretical and methodological provisions of moderncardboard relative to the normalized structure of the semiotic sides of the "object" language of the map. (obligatory, minimum necessary and sufficient for mapping means of cartographic modeling of features (qualitative, quantitative, functional) variousobjects, processes and phenomena of real reality and their changes in space and time). It is the sembotic structure interrelatedbetween the sides of the content that makes the map language functioning and determines the degree of perfection (quality) ofcartographic image.This language structure is a reference for requirements, which provides for the control of the correspondence of elements ofthe content of any geoimage (representation of graphic language spatially and expressed information) with compliance mappingpositions of mapping modeling. Thus, on the basis of Semitic analysis, in development of topographic map as tactical-piloting,the necessity of introduction to its digital model of two additional "Coloro-thematic" layers is determined: objects of aeronauticalinformation (dark blue) and "signal" component of the content of the map – signatures of their own names in Latin (light red)colors.

Molecular complexity of visual mapping: a challenge for regenerating therapy.

Investigating the cellular and molecular mechanisms involved in the development of topographically ordered connections in the central nervous system constitutes an important issue in neurobiology because these connections are the base of the central nervous system normal function. The dominant model to study the development of topographic maps is the projection from the retinal ganglion cells to the optic tectum/colliculus. The expression pattern of Eph/ephrin system in opposing gradients both in the retina and the tectum, labels the local addresses on the target and gives specific sensitivities to growth cones according to their topographic origin in the retina. The rigid precision of normal retinotopic mapping has prompted the chemoaffinity hypothesis, positing axonal targeting to be based on fixed biochemical affinities between fibers and targets. However, several lines of evidence have shown that the mapping can adjust to experimentally modified targets with flexibility, demonstrating the robustness of the guidance process. Here we discuss the complex ways the Ephs and ephrins interact allowing to understand how the retinotectal mapping is a precise but also a flexible process.

Cell type specific impact of cannabinoid receptor signaling in somatosensory barrel map formation in mice.

Endocannabinoids and their receptors are highly abundant in the developing cerebral cortex and play major roles in early developmental processes, for example, neuronal proliferation, migration, and axonal guidance as well as postnatal plasticity. To investigate the role of the cannabinoid type 1 receptor (CB1) in the formation of sensory maps in the cerebral cortex, the topographic representation of the whiskers in the primary somatosensory cortex (barrel field) of adult mice with different cell type specific genetic deletion of CB1 was studied. A constitutive absence of CB1 (CB1-KO) significantly decreased the total area of the somatosensory cortical map, affecting barrel, and septal areas. Cell specific CB1 deletion in dorsal telencephalic glutamatergic neurons only (Glu-CB1-KO) or in both glutamatergic and forebrain GABAergic neurons (Glu/GABA-CB1-KO) resulted in an increased septa area in the barrel field map. No significant modifications in area parameters could be observed in GABA-CB1-KO mice. These data demonstrate that CB1 signaling especially in cortical glutamatergic neurons is essential for the development of topographic maps in the cerebral cortex.

Vagus Motor Neuron Topographic Map Determined by Parallel Mechanisms of hox5 Expression and Time of Axon Initiation

Many networks throughout the nervous system are organized into topographic maps, where the positions of neuron cell bodies in the projecting field correspond with the positions of their axons in the target field. Previous studies of topographic map development show evidence for spatial patterning mechanisms, in which molecular determinants expressed across the projecting and target fields are matched directly in a point-to-point mapping process. Here, we describe a novel temporal mechanism of topographic map formation that depends on spatially regulated differences in the timing of axon outgrowth and functions in parallel with spatial point-to-point mapping mechanisms. We focus on the vagus motor neurons, which are topographically arranged in both mammals and fish. We show that cell position along the anterior-posterior axis of hindbrain rhombomere 8 determines expression of hox5 genes, which are expressed in posterior, but not anterior, vagus motor neurons. Using live imaging and transplantation in zebrafish embryos, we additionally reveal that axon initiation is delayed in posterior vagus motor neurons independent of neuron birth time. We show that hox5 expression directs topographic mapping without affecting time of axon outgrowth and that time of axon outgrowth directs topographic mapping without affecting hox5 expression. The vagus motor neuron topographic map is therefore determined by two mechanisms that act in parallel: a hox5-dependent spatial mechanism akin to classic mechanisms of topographic map formation and a novel axon outgrowth-dependent temporal mechanism in which time of axon formation is spatially regulated to direct axon targeting.

Uncoupling of EphA/ephrinA Signaling and Spontaneous Activity in Neural Circuit Wiring

Classic studies have proposed that genetically encoded programs and spontaneous activity play complementary but independent roles in the development of neural circuits. Recent evidence, however, suggests that these two mechanisms could interact extensively, with spontaneous activity affecting the expression and function of guidance molecules at early developmental stages. Here, using the developing chick spinal cord and the mouse visual system to ectopically express the inwardly rectifying potassium channel Kir2.1 in individual embryonic neurons, we demonstrate that cell-intrinsic blockade of spontaneous activity in vivo does not affect neuronal identity specification, axon pathfinding, or EphA/ephrinA signaling during the development of topographic maps. However, intrinsic spontaneous activity is critical for axon branching and pruning once axonal growth cones reach their correct topographic position in the target tissues. Our experiments argue for the dissociation of spontaneous activity from hard-wired developmental programs in early phases of neural circuit formation.

Developmental Mechanisms of Topographic Map Formation and Alignment

Brain connections are organized into topographic maps that are precisely aligned both within and across modalities. This alignment facilitates coherent integration of different categories of sensory inputs and allows for proper sensorimotor transformations. Topographic maps are established and aligned by multistep processes during development, including interactions of molecular guidance cues expressed in gradients; spontaneous activity-dependent axonal and dendritic remodeling; and sensory-evoked plasticity driven by experience. By focusing on the superior colliculus, a major site of topographic map alignment for different sensory modalities, this review summarizes current understanding of topographic map development in the mammalian visual system and highlights recent advances in map alignment studies. A major goal looking forward is to reveal the molecular and synaptic mechanisms underlying map alignment and to understand the physiological and behavioral consequences when these mechanisms are disrupted at various scales.

Correction: Pfeiffenberger et al., Ephrin-As and Patterned Retinal Activity Act Together in the Development of Topographic Maps in the Primary Visual System

Correction: Pfeiffenberger et al., Ephrin-As and Patterned Retinal Activity Act Together in the Development of Topographic Maps in the Primary Visual System

Role of EphA/ephrin‐A signaling in the development of topographic maps in mouse corticothalamic projections

Corticothalamic (CT) feedback outnumbers thalamocortical projections and regulates sensory information processing at the level of the thalamus. It is well established that EphA7, a member of EphA receptor family, is involved in the topographic mapping of CT projections. The aim of the present study was to dissect the precise impact of EphA7 on each step of CT growth. We used in utero electroporation-mediated EphA7 overexpression in developing somatosensory CT axons to dissect EphA7/ephrin-A-dependent mechanisms involved in regulating both initial targeting and postnatal growth of the CT projections. Our data revealed that topographic maps of cortical afferents in the ventrobasal complex and medial part of the posterior complex in the thalamus become discernible shortly after birth and are fully established by the second postnatal week. This process starts with the direct ingrowth of the CT axons to the designated areas within target thalamic nuclei and by progressive increase of axonal processes in the terminal zones. Large-scale overproduction and elimination of exuberant widespread axonal branches outside the target zone was not observed. Each developmental event was coordinated by spatially and temporally different responsiveness of CT axons to the ephrin-A gradient in thalamic nuclei, as well as by the matching levels of EphA7 in CT axons and ephrin-As in thalamic nuclei. These results support the concept that the topographic connections between the maps in the cerebral cortex and corresponding thalamic nuclei are genetically prespecified to a large extent, and established by precise spatiotemporal molecular mechanisms that involve the Eph family of genes.

Role of adenylate cyclase 1 in retinofugal map development

The development of topographic maps of the sensory periphery is sensitive to the disruption of adenylate cyclase 1 (AC1) signaling. AC1 catalyzes the production of cAMP in a Ca2+/calmodulin-dependent manner, and AC1 mutant mice (AC1−/−) have disordered visual and somatotopic maps. However, the broad expression of AC1 in the brain and the promiscuous nature of cAMP signaling have frustrated attempts to determine the underlying mechanism of AC1-dependent map development. In the mammalian visual system, the initial coarse targeting of retinal ganglion cell (RGC) projections to the superior colliculus (SC) and lateral geniculate nucleus (LGN) is guided by molecular cues, and the subsequent refinement of these crude projections occurs via an activity-dependent process that depends on spontaneous retinal waves. Here, we show that AC1−/− mice have normal retinal waves but disrupted map refinement. We demonstrate that AC1 is required for the emergence of dense and focused termination zones and elimination of inaccurately targeted collaterals at the level of individual retinofugal arbors. Conditional deletion of AC1 in the retina recapitulates map defects, indicating that the locus of map disruptions in the SC and dorsal LGN of AC1−/− mice is presynaptic. Finally, map defects in mice without AC1 and disrupted retinal waves (AC1−/−;β2−/− double KO mice) are no worse than those in mice lacking only β2−/−, but loss of AC1 occludes map recovery in β2−/− mice during the second postnatal week. These results suggest that AC1 in RGC axons mediates the development of retinotopy and eye-specific segregation in the SC and dorsal LGN.

Phr1 is required for proper retinocollicular targeting of nasal–dorsal retinal ganglion cells

Precise targeting of retinal projections is required for the normal development of topographic maps in the mammalian primary visual system. During development, retinal axons project to and occupy topographically appropriate positions in the dorsal lateral geniculate nucleus (dLGN) and superior colliculus (SC). Phr1 retinal mutant mice, which display mislocalization of the ipsilateral retinogeniculate projection independent of activity and ephrin-A signaling, were found to have a more global disruption of topographic specificity of retinofugal inputs. The retinocollicular projection lacks local refinement of terminal zones and multiple ectopic termination zones originate from the dorsal-nasal (DN) retinal quadrant. Similarly, in the dLGN, the inputs originating from the contralateral DN retina are poorly refined in the Phr1 mutant. These results show that Phr1 is an essential regulator of retinal ganglion cell projection during both dLGN and SC topographic map development.

Large Developing Receptive Fields Using a Distributed and Locally Reprogrammable Address–Event Receiver

A distributed and locally reprogrammable address-event receiver has been designed, in which incoming address-events are monitored simultaneously by all synapses, allowing for arbitrarily large axonal fan-out without reducing channel capacity. Synapses can change the address of their presynaptic neuron, allowing the distributed implementation of a biologically realistic learning rule, with both synapse formation and elimination (synaptic rewiring). Probabilistic synapse formation leads to topographic map development, made possible by a cross-chip current-mode calculation of Euclidean distance. As well as synaptic plasticity in rewiring, synapses change weights using a competitive Hebbian learning rule (spike-timing-dependent plasticity). The weight plasticity allows receptive fields to be modified based on spatio-temporal correlations in the inputs, and the rewiring plasticity allows these modifications to become embedded in the network topology.

Ephrin-As and Patterned Retinal Activity Act Together in the Development of Topographic Maps in the Primary Visual System

The development of topographic maps in the primary visual system is thought to rely on a combination of EphA/ephrin-A interactions and patterned neural activity. Here, we characterize the retinogeniculate and retinocollicular maps of mice mutant for ephrins-A2, -A3, and -A5 (the three ephrin-As expressed in the mouse visual system), mice mutant for the beta2 subunit of the nicotinic acetylcholine receptor (that lack early patterned retinal activity), and mice mutant for both ephrin-As and beta2. We also provide the first comprehensive anatomical description of the topographic connections between the retina and the dorsal lateral geniculate nucleus. We find that, although ephrin-A2/A3/A5 triple knock-out mice have severe mapping defects in both projections, they do not completely lack topography. Mice lacking beta2-dependent retinal activity have nearly normal topography but fail to refine axonal arbors. Mice mutant for both ephrin-As and beta2 have synergistic mapping defects that result in a near absence of map in the retinocollicular projection; however, the retinogeniculate projection is not as severely disrupted as the retinocollicular projection is in these mutants. These results show that ephrin-As and patterned retinal activity act together to establish topographic maps, and demonstrate that midbrain and forebrain connections have a differential requirement for ephrin-As and patterned retinal activity in topographic map development.

Retinotopic Map Refinement Requires Spontaneous Retinal Waves during a Brief Critical Period of Development

During retinocollicular map development, spontaneous waves of action potentials spread across the retina, correlating activity among neighboring retinal ganglion cells (RGCs). To address the role of retinal waves in topographic map development, we examined wave dynamics and retinocollicular projections in mice lacking the β2 subunit of the nicotinic acetylcholine receptor. β2 −/− mice lack waves during the first postnatal week, but RGCs have high levels of uncorrelated firing. By P8, the wild-type retinocollicular projection remodels into a refined map characterized by axons of neighboring RGCs forming focal termination zones (TZs) of overlapping arbors. In contrast, in P8 β2 −/− mice, neighboring RGC axons form large TZs characterized by broadly distributed arbors. At P8, glutamatergic retinal waves appear in β2 −/− mice, and later, visually patterned activity appears, but the diffuse TZs fail to remodel. Thus, spontaneous retinal waves that correlate RGC activity are required for retinotopic map remodeling during a brief early critical period.

Control of axon branch dynamics by correlated activity in vivo.

To determine how patterned visual activity regulates the development of axonal projections, we collected in vivo time-lapse images of retinal axons from albino Xenopus tadpoles in which binocular innervation of the optic tectum was induced. Axons added branch tips with nearly equal probability in all territories, but eliminated them preferentially from territory dominated by the opposite eye. This selective branch elimination was abolished by blockade of N-methyl-D-aspartate receptors. These results describe a correlation-based mechanism by which visual experience directly governs axon branch dynamics that contribute to the development of topographic maps.

DEVELOPMENT OF TOPOGRAPHIC MAPS FOR PRECISION FARMING WITH MEDIUM ACCURACY GPS RECEIVERS

The topographic map is considered by many to be an important base map for a precision farming GIS(Geographic Information System). Previous work has shown that dual-frequency survey grade GPS (Global PositioningSystem) receivers are capable of producing accurate position data from a moving vehicle in a short time from whichtopographic maps can be developed. However, this type of GPS receiver is expensive and somewhat difficult to useproperly. This article presents the results from using sub-meter horizontal accuracy GPS receivers to collect multiplepasses of GPS data during normal field operations to develop topographic maps. The results show that: (1) it is possibleto develop a topographic map with a standard deviation of vertical error on the order of 10-12 cm with a sub-meterhorizontal position accuracy GPS receiver, and (2) when data is collected under controlled GPS windows, a minimum of10 passes of data with appropriate data processing is sufficient for the development of topographic maps with sub-meterGPS receivers.

DEVELOPMENT OF TOPOGRAPHIC MAPS FOR PRECISION FARMING WITH KINEMATIC GPS

The objective of this study was to examine the potential to use real-time kinematic differential GPS (RTK-DGPS)to collect GPS data on a moving vehicle for the development of topographic maps. An intensive study on a 1.5 ha field on anapproximate 3 m grid spacing was first conducted, using two GPS data collection modes, stop & go (using a tripod GPSantenna mount) and kinematic (with tractor mounted GPS antenna). It was found that the standard deviation of the elevationerror between 10 true error points and the calculated topographic surface ranged from 2 to 3 cm for data collected on anapproximate 3 m grid. The elevation error for derived grid spacings of 9, 18, and 33 m ranged from 2 to 5 cm. On a second20 ha field, only RTK-DGPS data was collected on an approximate 10 m grid spacing, with a resulting elevation error of4 cm using stop-and-go true error points, and 6 cm using RTK-DGPS true error points. A third 115 ha field was studied bycollecting data on an approximate 30 m grid with RTK-DGPS, with a resulting elevation error of 9 cm. The results arepositive and indicate that the technique of collecting RTK-DGPS data on a moving vehicle is a viable means by which datacan be collected to quickly develop topographic maps for precision farming and other applications.