dendrite
Enable an AI agent to recognise a neuronal dendrite, assess its observed structure and functional condition, and judge which observations or interventions are justified, provisionally interpreting the undefined registry term in its neuronal sense.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to recognise a neuronal dendrite, assess its observed structure and functional condition, and judge which observations or interventions are justified, provisionally interpreting the undefined registry term in its neuronal sense.
A dendrite (also dendron) is a typically tapering, branched cytoplasmic process of a neuron that receives synaptic, and in some cells sensory, input, spatially and temporally integrates the resulting local potentials, and conducts them toward the soma, with some dendrites also supporting regenerative spikes, back-propagating action potentials, and retrograde transmitter release.
It can be Trace the dendrite from its root through visible branches and flag ambiguous continuity.; Measure shaft geometry and spine distribution within explicitly evaluable regions.; Associate local contacts and recorded signals with particular branches, shafts or spines.; Compare repeated observations for supported structural or functional changes.; Assess whether a proposed local recording, stimulation or labelling intervention is accessible and justified by the preparation and evidence.; Record intervention location, exposure and response while distinguishing dendritic effects from effects on the parent neuron or neighbouring structures..
Distinguishing features
Establish neuronal context and traced continuity with a parent neuron before classifying a branching structure as a neuronal dendrite.
Distinguish dendrite from axon using convergent evidence from cellular origin, morphology, molecular labelling and neuron type; branching shape alone is insufficient.
Distinguish the dendritic shaft and its branches from the soma by recording the anatomical boundary used and whether that boundary is visible.
Distinguish an individual dendrite from the complete dendritic arbor by identifying its root and the rule for assigning downstream branches.
Distinguish spines or other surface protrusions from shaft branches using their connection and morphology; a protrusion alone does not establish a synapse.
Scope
+ Identification and boundaries of an individual dendrite within its parent neuron
+ Branch geometry, continuity and membership in the neuron's dendritic arbor
+ Dendritic spines, shaft specialisations and locally attributed synaptic contacts
+ Spatially and temporally resolved electrical, biochemical and structural observations
+ Dendrite-specific access, intervention constraints and observed responses
- Crystalline, mineral and electrochemical dendrites
- Whole-neuron identity, physiology and viability except as context for this dendrite
- Axons, axon terminals and their propagation or output machinery
- Complete synapses, including presynaptic machinery, beyond their interface with this dendrite
- Neural circuit computation, organism behaviour and clinical diagnosis
- General laboratory equipment and experimental protocols
Characteristics
- Dendritic identity confidence
- supported | provisional | unresolved | contradicted, with supporting observations Prevents a branching profile or isolated marker from being treated as decisive identification.
- Parent neuron and root attachment
- Referenced neuron and observed attachment location; unknown when untraced Anchors identity and establishes which arbor the dendrite belongs to.
- Dendrite class
- Apical | basal | other context-defined class | unclassified | not applicable Supports comparison within an appropriate neuron type without imposing a classification on every neuron.
- Branch connectivity
- Parent and child segments, branch points and terminal status Separates genuine branching from crossings, occlusion and incomplete reconstruction.
- Reconstructed path length
- µm, with endpoints and observed coverage Describes spatial extent without treating an incomplete trace as the complete dendrite.
- Shaft diameter profile
- µm by position, with measurement method and uncertainty Makes tapering, focal swelling and comparisons between locations assessable.
- Spine density
- Observed spines per µm of evaluable shaft, with detection criteria Allows local structural comparison while preserving the distinction between undetected and absent spines.
- Attributed synaptic contacts
- Contact location, partner if known, shaft or spine association, and evidence strength Separates established contacts from proximity and supports local input analysis.
- Local membrane potential
- mV by location and time, when directly measured or explicitly estimated Connects electrical state to the particular region sampled.
- Local calcium readout
- Calibrated concentration or explicitly identified reporter units such as ΔF/F₀ Preserves the distinction between an optical signal and a calibrated biochemical measurement.
- Structural condition
- Observed continuity, swelling, beading, fragmentation or remodelling, with time and confidence Records visible condition without automatically inferring viability or a cause.
- Observation context
- Living or fixed preparation, species, neuron type, developmental stage and acquisition method where known Determines which comparisons and functional interpretations are defensible.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Dendritic identity and boundaries Establish what neuronal structure is being modelled and where the individual dendrite begins and ends.
An undefined registry label and branching morphology cannot by themselves establish neuronal dendritic identity.
Neuronal attribution
Connect the candidate dendrite to a neuron and evaluate competing identifications.
Evidence for dendritic identity
Record the observations supporting dendritic identity and any unresolved axonal or non-neuronal interpretation.
- What evidence identifies this structure as a neuronal dendrite rather than an axon, glial process or non-neuronal branching structure? definition
- Which images, traces, labels or other observations support attribution to the stated parent neuron? provenance
Individual dendrite delimitation
Specify the root, included branches and observational limits of this dendrite.
Root and membership rule
Make the boundary between soma, individual dendrite and complete arbor explicit.
- Where is this dendrite's root, and what rule assigns downstream branches to it? boundary
- Which apparent endpoints are observed tips, and which are cuts, occlusions or exits from the imaging volume? boundary
Branch architecture Describe the dendrite's connected geometry at a resolution supported by observation.
Dendritic topology and local shaft dimensions are needed to locate inputs, compare changes and target interventions.
Branch connectivity
Resolve branch points, segment relationships and tracing ambiguity.
Supported branch topology
Record which segment connections are demonstrated and which remain uncertain.
- Which segments connect at each branch point, and how were crossings distinguished from connections? measurement
- Which connections cannot be resolved at the available spatial resolution? boundary
Shaft geometry
Measure spatial extent and local calibre along identified paths.
Length and calibre profile
Record path lengths and diameter variation with their sampling and uncertainty.
- What are the reconstructed path lengths and shaft diameters, and where were they measured? measurement
- How do projection, optical resolution and preparation-related distortion limit these measurements? provenance
Spines and input interfaces Locate dendritic surface specialisations and assess evidence for local synaptic contacts.
Spines, shaft contacts and nearby presynaptic structures must be distinguished before inferring the dendrite's inputs.
Surface specialisations
Describe observed protrusions and the shaft regions in which they could be detected.
Spine observations
Record spine occurrence, morphology and uncertainty without equating every protrusion with a synapse.
- Which protrusions meet the stated criteria for spines, and which remain unclassified? definition
- What spine density and morphology are measurable within the evaluable shaft length? measurement
Local synaptic attribution
Associate candidate or confirmed contacts with particular dendritic locations.
Contact evidence and location
Separate proximity-based candidates from contacts supported by appropriate structural or functional evidence.
- What evidence supports each attributed synaptic contact, and does it establish contact beyond spatial proximity? provenance
- Is the contact assigned to a shaft or spine, and which partner and input properties are established? boundary
Local state and change Record dendritic signals and structural changes at the locations and times actually observed.
A local readout or morphological change cannot establish the state of the entire dendrite without additional evidence.
Electrical and biochemical readouts
Preserve the identity, calibration and spatial coverage of local functional measurements.
Local signal interpretation
Distinguish directly measured quantities, reporter signals and inferred events.
- What electrical or biochemical quantity was recorded, at which dendritic location and with what temporal resolution? measurement
- What calibration and accompanying evidence support interpreting the readout as a particular local event? provenance
Structural dynamics
Assess changes in branches, shaft condition and spines across comparable observations.
Supported dendritic change
Record growth, retraction, spine turnover or apparent damage while retaining alternative explanations.
- Which structural features changed between registered observations, and by how much? measurement
- What evidence separates biological change from motion, labelling variation, segmentation error or preparation damage? provenance
Dendritic access and intervention Determine which local actions are feasible and how their effects can be attributed.
A dendrite's size, location and preparation constrain access, while local manipulations may also affect connected or neighbouring structures.
Target accessibility
Match a proposed action to a resolved dendritic target and the available preparation.
Local action feasibility
Record whether a specified shaft segment, branch or spine can be observed or manipulated with adequate selectivity.
- Which dendritic location is the target, and can the proposed method resolve and reach it in this preparation? action
- What spatial spread or physical disturbance could involve neighbouring branches, synapses or cells? boundary
Response attribution
Relate an intervention to measured local and wider effects.
Intervention response evidence
Record exposure, baseline and follow-up observations sufficient to judge the claimed dendritic response.
- What intervention was applied, where and when, and what local response was observed relative to baseline? action
- Which controls or simultaneous observations distinguish a local dendritic effect from parent-neuron activity or experimental artefact? provenance
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- apical dendrite
- basal dendrite
- oblique dendrite
- apical tuft
- spiny dendrite
- aspiny (smooth) dendrite
- primary (stem) dendrite
- higher-order dendritic branch
- Which of these kinds and varieties hold for the sense of dendrite this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q12821248 - Neuronal dendrite; Wikipedia anatomical-terminology box links this item, distinct from metallic dendrite Q11646943.
- MeSH - D003712 - Descriptor Dendrites, U.S. National Library of Medicine.
- FMA - 67314 - Foundational Model of Anatomy class for the neuronal dendrite.
- Which of these identifiers and schemes hold for the sense of dendrite this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Foundational Model of Anatomy class 67314, issued by the University of Washington Structural Informatics Group.
- MeSH descriptor D003712 (Dendrites), issued by the U.S. National Library of Medicine as a controlled biomedical vocabulary, not a product or safety code.
- Which of these standards and regulation hold for the sense of dendrite this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Golgi, intracellular-dye and fluorescence reconstructions of dendritic arbors to classify neuron types and map receptive fields.
- Patch-clamp, calcium and voltage imaging of dendritic integration, back-propagating spikes and dendritic spikes.
- Neuropathology of arbor simplification and spine loss in neurodevelopmental and neurodegenerative disease.
- Cable and compartmental models that treat dendrites as the spatial filter of synaptic input.
- Dendritic release of oxytocin, vasopressin and dopamine in neuroendocrine and midbrain circuits.
- Electron-microscopy connectomics assigning synapses onto dendritic shafts versus spines.
- Which of these real-world use hold for the sense of dendrite this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- dendritic shaft diameter (typical cortical pyramidal) - 0.5 to several - µm
- presynaptic partners onto a large pyramidal dendritic tree - about 30000 (some neurons up to about 100000) - synapses
- hormone-linked change in CA1 pyramidal dendritic (spine) density - up to about 30 - %
- Which of these typical measurements hold for the sense of dendrite this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Reduced hippocampal CA1/CA4 dendritic branching reported in autism spectrum disorder.
- Reduced basal dendritic branching in motor cortex and subiculum in Rett syndrome.
- Reduced dendritic arbor and spine density in schizophrenia.
- Shorter apical and basal dendrites in hippocampal CA1 in Alzheimer's disease.
- Spine loss, fragmentation and arbor simplification more generally, tightly correlated with impaired nervous-system function.
- Sensory deprivation (for example dark rearing) reducing spine number and altering branch distribution in visual cortex.
- The structure itself is not a public hazard; failure is of the neuron's input and integration, not of an external device.
- Which of these failure modes and hazards hold for the sense of dendrite this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Insect unipolar neurons place dendrites on one branch of a somatic stalk, unlike the multipolar trees typical of vertebrate principal cells.
- Some neurons, including certain invertebrate sensory cells, lack a specialized axon and transmit via dendrites, so the textbook receive-on-dendrite / send-on-axon split is not universal.
- The peripheral process of vertebrate pseudounipolar sensory neurons is often called a dendrite in teaching but conducts as an axon.
- The same English word names a different physical object in metallurgy and mineralogy (branched crystals); that sense is a separate registry item (Wikidata Q11646943).
- The anatomical term dendrite was coined in 1889 by Wilhelm His for the smaller protoplasmic processes of the nerve cell; dendron remains a synonym.
- Which of these regional variation hold for the sense of dendrite this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- axon - Dendrites usually taper, branch close to the soma and receive most synapses; axons typically keep a more constant caliber, can be much longer, often start at an axon initial segment, and are the usual output path.
- neurite - A neurite is any cytoplasmic process of a neuron, used especially before axon versus dendrite identity is settled in developing or cultured cells.
- dendritic spine - A spine is a micrometre-scale protrusion on a dendrite that bears most excitatory synapses; it is a part of a dendrite, not the dendrite.
- soma (cell body) - The soma is the nucleated cell body from which dendrites arise, not a branched receptive process.
- dendritic cell - An antigen-presenting immune cell; the shared name is historical (branched morphology), not a neuronal process. Wikipedia disambiguates the two.
- crystal or metallic dendrite - A tree-like crystal grown from melt, solution or electrodeposition (snow, frost, cast metal, battery lithium); test: crystalline solid without neuronal cytoplasm, synapses or membrane potential.
- glial process - Thin astrocytic or other glial branches occupy the same neuropil but lack neuronal postsynaptic specializations of that cell and do not define a dendritic tree of a neuron.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of dendrite this model covers, and on what evidence? provenance
Sources
- Dendrite - Wikipedia (Wikimedia Foundation) - Specialist definition of the neuronal process; MeSH D003712, FMA 67314 and Wikidata Q12821248; apical/basal and arbor-pattern kinds; axon contrast; synaptic load figures; electrical properties including passive spread, back-propagation and dendritic spikes; dendritic transmitter release; clinical arbor and spine changes; insect unipolar versus vertebrate trees.
- Pyramidal cell - Wikipedia (Wikimedia Foundation) - Working split into one apical dendrite versus several basal dendrites; typical pyramidal dendrite shaft diameter from about 0.5 µm to several micrometres.
- Pyramidal neurons: dendritic structure and synaptic integration - Nature Reviews Neuroscience (Springer Nature) - That pyramidal cells are defined by basal and apical trees including an apical tuft; domain-specific synaptic input; spines as the usual excitatory contact; dendritic voltage-gated channels, back-propagating spikes and dendritically initiated spikes.
- Dendrite (crystal) - Wikipedia (Wikimedia Foundation) - Neighbour sense: a multi-branching crystal habit (snow, frost, minerals, metals), not a neuronal process.
What the second pass must settle
- Does vr.tr.dendrite denote a neuronal dendrite, a crystalline or electrochemical dendrite, or an intentionally broader concept?
- Does an existing Vercy world model already own the intended concept, requiring a registry link instead of a separate model?
- Which neuron types and developmental contexts must the model support, and which dendrite-versus-axon identification criteria are valid in each?
- What minimum evidence should establish a spine, a synaptic contact or a local dendritic electrical event for each supported observation method?
- Which context-specific observations justify interpreting dendritic morphology as injury, recovery or plasticity rather than leaving the cause unresolved?