Publication-ready icon

Action Potential Diagram Labeled 02

Name: SciFig
Author: SciFig

A labeled action potential graph plotting membrane potential over time, with threshold, depolarization, the +30 mV peak, repolarization, and hyperpolarization marked.

Editable SVGPublication-readyScientifically accurateFree to start

Use this icon Edit this icon

Figure prompt

Core Subject (e.g., Cas9 protein cutting DNA)

Action / Details (e.g., Double strand break, detailed molecular view)

Start with 200 free credits|No credit card required

Get up to 400 free credits on day one when you join through an invite.

6 input modes · 6 publication stylesEvery text editable · Multimodal enhanceEditable PPTX · Layered SVG · 8K PNG / JPG

What is Action Potential Diagram Labeled 02?

A labeled action potential graph is a diagram that plots a neuron's membrane potential over time as it fires, with each phase named. It starts near the -70 mV resting potential, rises to the threshold, depolarizes sharply to a peak around +30 mV, repolarizes back down, dips into hyperpolarization, and returns to rest. With SciFig you describe the trace in plain language and generate a clean, editable action potential graph, ready to relabel and export.

Why the trace is drawn from the electrophysiology, not from memory

Every phase name on the curve maps to a specific ionic event, so a trace with the wrong shape teaches the wrong mechanism — the rising phase must be steeper than the falling phase because voltage-gated Na⁺ conductance activates far faster than K⁺ conductance.
The axis values are the content. A trace without millivolts on the y-axis and milliseconds on the x-axis is decoration; with them it is a quantitative claim a reader can check against their own recordings.
The undershoot is diagnostic and routinely omitted. Delayed-rectifier K⁺ channels close slowly, so the membrane transiently sits below rest — a curve that returns straight to baseline has drawn away the mechanism.
The all-or-none property depends on threshold being drawn as a distinct level with subthreshold depolarisations failing at it; a figure showing only the successful spike cannot make that argument.
Cell type matters and is usually left implicit. A squid or mammalian axonal spike lasts ~1–2 ms; a cardiac ventricular action potential has a plateau and lasts 200–400 ms. Reusing one shape for the other is a substantive error.

Phases and features to label

Resting membrane potential at approximately −70 mV (neuronal), set by K⁺ leak conductance and the Na⁺/K⁺-ATPase, drawn as a dashed baseline that persists across the whole x-axis.
Threshold at roughly −55 mV, marked as a horizontal dashed line, with at least one failed subthreshold depolarisation shown beneath it to make the all-or-none point.
Rising phase / depolarisation: rapid Na⁺ influx through voltage-gated Na⁺ channels in regenerative positive feedback, driving the membrane toward E_Na (≈ +60 mV).
Peak at about +30 mV — note that it undershoots E_Na because Na⁺ channels begin inactivating and K⁺ channels begin opening before equilibrium is reached.
Falling phase / repolarisation: Na⁺ channel inactivation gates close while delayed-rectifier K⁺ channels open, so net K⁺ efflux returns the membrane toward rest.
Hyperpolarising afterpotential (undershoot) below −70 mV, approaching E_K (≈ −90 mV), caused by slow K⁺ channel closure.
Refractory periods drawn as bars beneath the trace: the absolute refractory period (Na⁺ channels inactivated, no stimulus can fire a second spike) and the relative refractory period (recovering channels plus residual K⁺ conductance, so a stronger-than-normal stimulus is required).

Where the labelled trace is used

Neuroscience teaching figures and lecture slides on excitability, conduction, and the Hodgkin–Huxley formulation.
Pharmacology figures showing channel-blocker effects — tetrodotoxin abolishing the upstroke, TEA broadening repolarisation, local anaesthetics on use-dependent block.
Channelopathy and disease figures: gain-of-function Na⁺ channel mutations in epilepsy, loss-of-function in periodic paralysis, and long-QT variants in the cardiac analogue.
Patch-clamp methods panels, where the schematic trace is placed alongside real recordings to orient the reader before showing data.
Comparative panels contrasting neuronal, cardiac (phases 0–4 with a Ca²⁺-mediated plateau), and skeletal muscle waveforms on a shared time axis.
Computational neuroscience figures where a modelled spike is compared to the canonical shape, and the conductance traces (g_Na, g_K) are stacked below.