Eisynaptisoituen

Eisynaptisoituen are a term used in speculative neuroscience to denote a proposed class of nanoscale signaling entities that mediate communication between cells at or near synaptic sites, but without forming classical chemical synapses. The term is not widely used in mainstream experimental literature and remains a hypothetical construct found in theoretical discussions and some speculative reviews.

In the proposed model, eisynaptisoituen are envisioned as vesicle-like particles, roughly 50 to 150 nanometers in diameter, enriched for membrane-trafficking proteins, and loaded with neuromodulators, peptides, or RNA fragments. They are posited to travel through the extracellular milieu and interact with nearby or distant cells via surface receptors or cytoplasmic signaling pathways, rather than by classic neurotransmitter release.

Proposed release and targeting mechanisms include activity-dependent exocytosis from neurons or glial cells and uptake by recipient cells through endocytosis or direct fusion. The interactions are described as modulating receptor activity, intracellular signaling cascades, or gene expression without generating traditional postsynaptic potentials.

Evidence and status: There is no broadly accepted in vivo evidence for eisynaptisoituen. Some in vitro experiments and computer simulations offer hypothetical signatures such as vesicle-like morphology, distinct surface markers, or correlated release patterns, but these claims lack standardized detection methods and independent replication. The concept has not been incorporated into standard ontologies or databases.

Potential significance: If confirmed, eisynaptisoituen would broaden the understanding of non-synaptic intercellular communication and could inform models of synaptic plasticity, neural network dynamics, and therapeutic delivery systems. Challenges include establishing reliable identification criteria, differentiating them from exosomes and other extracellular vesicles, and developing robust, noninvasive detection techniques.

See also: extracellular vesicles, exosomes, neuromodulation, non-synaptic transmission.