Histamine is a signaling chemical best known for its role in allergic reactions. When the immune system detects a foreign substance or allergen, specialized cells like mast cells and basophils release histamine. This triggers an inflammatory response, causing blood vessels to dilate and become more permeable, which leads to common allergy symptoms like a runny nose, sneezing, and itching as the body tries to expel the perceived threat. Beyond allergies, histamine also functions as a neurotransmitter in the brain, where it helps regulate the sleep-wake cycle and cognitive function, and it plays a part in stimulating stomach acid secretion.

Explore searchable catalogue of hundreds of molecules, including details on how models were generated.

Notes

• If you happen to break something, use superglue to fix it. It will make the broken part even stronger.
• I decided to go with the ball-and-stick type, as it is easiest to color, is rigid, and looks awesome.
• The model represents the major resonance contributor.
• I oriented the model for optimal strength/waste/time compromise, but if you decide to reorient it, try to avoid placing bonds along the Z-axis, as they will be very easy to break.
• Supports removable without too much worry of damaging model if you are careful with scalpel and do of paper-sanding afterwards.
• You can use PETG as support material (don't forget to set the heatbed to 70 °C!) and PLA for the model itself (the support then come off much easier). For extra swag, use PLA support filament or PVA as supports.
• Recommended colorization is based on the Corey–Pauling–Koltun (CPK) palette (Figure 1). To quickly change colors, use the settings depicted in Figure 2.
  Alternatively, if you want to save filament and time, print the model in full-white and paint it with a permanent marker.

Figure 1. Recommended palette based on CPK coloring.

Figure 2. Setting to quickly color atoms with one click.

Happy printing!s