Fechnerin

Fechnerin is a hypothetical neurotransmitter-like molecule used in educational contexts to illustrate interactions between sensory input and perception. It is not an established endogenous compound, and there is no peer-reviewed evidence of its existence in humans or animals. The term is often employed in textbooks and classroom discussions to model how chemical signals could, in theory, influence perceptual thresholds.

The name Fechnerin derives from Gustav Fechner, the 19th‑century psychologist who formulated Fechner's law on the relationship between stimulus intensity and perceived magnitude. In theoretical discussions, Fechnerin is imagined as a signaling molecule that could modulate neural gain in sensory pathways.

In many classroom models, Fechnerin is described as a small peptide or amide with selective affinity for a prospective receptor, tentatively named FechnerR. These representations are schematic and vary between curricula; no validated synthesis pathway or structural assignment exists in the scientific literature.

Proposed mechanisms place Fechnerin at the interface between receptor activation and perceptual scaling. In such models, changes in Fechnerin signaling would alter the slope of the psychophysical function, contributing to non-linear perception consistent with Fechner's law. However, these are purely hypothetical constructs.

Because Fechnerin has no empirical basis, it is primarily a pedagogical tool rather than a subject of experimental research. Some scholars emphasize that fictional examples should be clearly distinguished from real biochemical agents to avoid confusion.

See also: Fechner's law, psychophysics, receptor theory.