Domain: Healthcare — Pathophysiology
Target concept: Vascular dilation and exudative response during inflammation

Video generation prompt: Intradermally inject histamine solution into the mouse ear, and observe and measure changes in ear skin color and thickness over time.

Evaluation guide:
(i) Target concept: Histamine-induced acute inflammatory response in murine dermis.
Minimum mechanism: Intradermal histamine delivery must trigger rapid, localized, and concurrent vascular dilation (causing erythema) and increased vascular permeability (causing exudative edema), both anatomically confined to the injection site and its immediate radial vicinity.
(ii)Storyline: [Baseline] Mouse ear at rest: pale pink, thin contour, matte surface. → [Action] Syringe needle approaches and inserts intradermally at ear base. → [Causal onset] Within <1s post-insertion: first red hue appears *exactly at needle tip location*, then expands radially. → [Causal progression] Simultaneously, ear tissue visibly thickens *only around injection zone*, elevating contour and increasing surface gloss/translucency due to fluid accumulation. → [Persistence] Both redness and swelling remain stable and co-localized for duration; no regression, spread beyond anatomical boundaries, or secondary phenomena (e.g., bleeding, necrosis). Perspective: fixed dorsal-view macro shot; full ear in frame; injection site unoccluded before/during/after needle contact.

Manual:
Experimental Procedure
1. Restrain mouse and expose right ear.
2. Load histamine solution into insulin syringe with 30G needle.
3. Insert needle intradermally at ear base, inject 20 µL.
Observation of Experimental Phenomena
- Immediate localized reddening radiating from injection site
- Visible thickening/swelling of ear tissue at injection site
- Increased surface translucency/glossiness in swollen region
Summary of Experimental Principles
Histamine binds H1 receptors on dermal arterioles → vasodilation → increased blood flow → erythema; simultaneously increases capillary permeability → plasma exudation → edema and tissue swelling.

Prompt Grounding rubric:
level_1: No syringe or needle appears anywhere in the clip; no mouse ear is shown; no histamine solution container or syringe barrel is visible; the ear shows no distinguishable earlier vs. later state at all; the scene isn't recognizably a mouse-ear injection setup.
level_2: A mouse ear is shown sitting still, but no syringe or needle ever appears; no injection action takes place; no histamine solution container is visible anywhere; the clip never shows any progression from an earlier moment to a later one.
level_3: A mouse ear is shown; a syringe with a needle is present and positioned near the ear; the needle is shown going into the ear tissue; the ear is shown both before and after this insertion; but the clip doesn't clearly set the earlier state and the later state apart from each other, for example with no clear moment marking where one ends and the other begins.
level_4: Everything required for level 3 is shown, and in addition the histamine solution container (a labeled vial or a syringe barrel with visible clear liquid) is shown; the needle entering the ear tissue is shown unambiguously rather than merely implied; the clip clearly separates an early state of the ear from a later state of the same ear; the same ear stays in view from the same camera angle across the whole sequence.
level_5: Everything required for level 4 is shown, and in addition the needle insertion is shown without any cut or jump in camera angle right up to and through the moment of entry; the same single ear, syringe, and camera framing are used continuously from before the injection through to the end of the clip; nothing else about the setup (background, animal positioning, framing) changes between the early and later states other than what happens to the ear itself.

Scientific and Causal Correctness rubric:
level_1: The ear's color and thickness never change at all; or a change happens that contradicts what histamine should cause: for example the skin visibly pales or blanches rather than reddening, the ear gets thinner rather than thicker, or the tissue shows blackening or peeling rather than any inflammatory response.
level_2: Only the ear's color changes, for example a flat, uniform redness with no spread pattern, with no accompanying thickness change; or only the thickness changes with no accompanying redness; or neither change is shown as following from the needle's entry; or redness appears before the needle ever touches the ear.
level_3: Redness appears after the needle goes in and starts at the injection site before spreading outward from there; the ear's thickness increases in the area right around that same site; both of these are present, but there's no clear before/after contrast to judge them against, and the swollen area doesn't show any extra shine or translucency that would suggest fluid buildup.
level_4: Redness clearly starts right at the injection site and spreads outward from it; the thickened area is confined to the region around the injection site and visibly changes the ear's outline; both the redness and the thickening only begin after the needle goes in and then stay present for the rest of the clip; the swollen area shows some added shine or translucency compared to the rest of the ear; nothing contradictory happens, such as blanching, blistering, or bleeding.
level_5: Everything required for level 4 is shown, and in addition the reddened area follows a fine, branching pattern resembling small blood vessels rather than a flat blotch; the thickened area bulges out smoothly and symmetrically, without any tearing or creasing of the skin; the added shine or translucency is confined to the swollen area and gradually becomes more noticeable as the clip goes on; the redness and swelling never fade or shrink back down at any point before the clip ends.

Spatiotemporal Consistency rubric:
level_1: The mouse ear vanishes and then reappears; the syringe jumps from one spot to another with no motion in between; the picture's brightness or shadowing changes abruptly; the ear flips or rotates to a different angle with no visible motion getting it there; the clip stutters in a way that makes the needle seem to jump position.
level_2: There's a hard cut between the before-injection and after-injection shots rather than continuous footage; the camera jitters or the zoom level shifts noticeably while the needle approaches; the ear's visible side switches, for example front to back, without any turning motion shown; the shadow the syringe casts points in a different direction than the light source would suggest.
level_3: The camera position stays the same throughout; the ear stays fully visible and steady in frame; the syringe's motion from approach to insertion looks like one continuous movement; nothing teleports or changes shape unnaturally; the overall brightness of the shot and the direction of the visible shadows stay the same from the first frame to the last, aside from a brief moment where the needle tip is hidden behind fur.
level_4: Everything required for level 3 is shown, and in addition the injection site stays visible before, during, and after the needle makes contact; the ear's outline is never cut off by the frame edge or stretched out of shape; the syringe's shaft and needle tip stay fully in view while moving; nothing about the ear's shape looks warped or distorted from an odd camera perspective.
level_5: Everything required for level 4 is shown, and in addition the syringe appears to move at a steady, constant speed rather than speeding up or slowing down oddly; the ear tissue only moves or dents right where the needle touches it, without the whole ear jiggling or bouncing; the ear and the background behind it stay visually consistent with each other as the camera view is held; details like fur texture and visible small vessels stay recognizable and steady across the whole clip.