Create a scientific figure about: Neuron synapse ultrastructure with vesicles and postsynaptic density.
Visual style: Botanical Field Guide.
Requirements:
- publication-ready scientific quality
- clear labels and directional arrows where appropriate
- avoid cartoon style, avoid meme style, avoid stock-photo look
- avoid neon glow and over-sharpened CGI look unless explicitly requested
- composition optimized for research papers and academic slides
- category context: micro-structures
- field-guide illustration style with disciplined line work and restrained fill color
- taxonomic and anatomical callouts arranged for textbook readability
- natural pigment behavior and paper-friendly texture without painterly chaos
