Perineuronal nets: past and present

Golgi ranked the peripheral reticulum - which adheres intimately to nerve c ell surfaces - alongside the intracellular reticulum, or Golgi apparatus,wh ich immortalized his name.At first dismissed as an artefact of capricious s taining techniques, this peripheral reticulum, or perineuronal net, is now recognized as a genuine entity in neurocytology. it represents a complex of extracellular matrix molecules interposed between the meshwork of glial pr ocesses, from which they are indistinguishable, and nerve-cell surfaces. In no other branch of neuroscience has the waxing and waning of interest in a ny morphological entity been so pronounced as in the case of the perineuron al net. This review traces the history of this enigmatic structure from its conception to the present time, brings to light the keen observational pow ers of morphologists at the turn of the century and reveals how their sagac ious forethought anticipated current thinking on the role of perineuronal n ets.