intercellular

Intercellular is an adjective used in biology to describe phenomena, structures, or processes that occur between cells. In tissues, intercellular interactions coordinate development, metabolism, and responses to injury, enabling cells to function as a coordinated unit rather than as isolated units.

Intercellular space refers to the narrow extracellular compartment between adjacent cells within a tissue. It contains interstitial fluid and extracellular matrix components, and it serves as the medium for diffusion of nutrients, signaling molecules, and waste products. The size and composition of this space influence transport and cell adhesion.

Intercellular communication includes direct and indirect methods. Direct communication occurs via gap junctions, allowing ions and small metabolites to pass between neighboring cells. Cells also connect through junctions such as tight junctions and desmosomes that organize tissue structure and regulate transport and mechanical coupling. Contact-dependent signaling uses membrane-bound signals engaging receptors on adjacent cells. Indirect signaling releases secreted molecules: paracrine signals affect nearby cells, autocrine signals target the signalling cell itself, and endocrine signals travel through the bloodstream to distant targets. In plants, plasmodesmata connect cytoplasm between cells, enabling exchange of signals and materials.

Intercellular adhesion depends on specialized molecules such as cadherins, claudins, and desmosomal proteins that form junctions and maintain tissue architecture. These connections allow coordinated responses and mechanical stability essential for tissue integrity.

Disruption of intercellular communication or adhesion can contribute to developmental disorders, infectious diseases, and cancer progression. Understanding intercellular processes informs fields from histology to neurobiology and immunology.