Cytoplasmic syncytial interneuronal connection in molluscs

The paired neuroglial and interglial membranes in the crayfish stretch receptor and their local disorganization

“…How is the flux of ions and molecules prevented? Unlike the open perforations observed by Peracchia et al (1981) and Sotnikov et al (−2010), in the crayfish stretch receptor all PM defects are sealed by the diffuse proteolipid material, which can prevent or limit free passage between the contacting neuronal and glial cells, and, despite the local disorganization, the neuroglial border is maintained in its entirety. The presence of this diffuse material is not an artifact of preparation and fixation.…”

“…Formation of tight junctions between paired membranes has been suggested to precede PM fusion, destabilization, formation of vesicles, and perforations (Samosudova et al, ; Sotnikov and Paramonova, ; Sotnikov et al, ). The presence of unsealed PM perforations between crayfish axons and glial cells (Peracchia, ; Sotnikov et al, ) and between neurons of crayfish, mollusks, and mammals (Sotnikov et al, ; Sotnikov and Paramonova, ) has been previously reported. This contradicts the well‐accepted Ramon y Cahal neuronal paradigm and returns to C. Golgi's concept of the syncytial nervous system.…”

“…The following lipid and protein rearrangement leads to formation of vesicles and perforations in the paired membranes that can form the large‐scale passages and syncytial coupling between contacting cells. Such perforations have been observed between neurons and between neurons and glial cells of crayfish, mollusks, and mammals (Peracchia, ; Samosudova et al, ; Sotnikov et al, ; Sotnikov and Paramonova, ). The ion fluxes through such perforations should rapidly decrease ionic gradients and membrane potential and eliminate neuronal activity.…”

Use of Cell Culture to Prove Syncytial Connection and Fusion of Neurons

“…After information of absolute facts of fusion of nerve processes in invertebrates [16], some authors were ready to recognize the giant neurons to be the non-nerve cells rather than to agree with facts of their syncytial connection [17]. It is impossible to ignore detection of the syncytial connection in molluscs, crustaceans, polychaetes, and other invertebrates [18][19][20][21][22][23][24]. All these works first of all offer absolute proofs of that the interneuronal syncytium in the nervous system in principle does exist.…”

Interneuronal Membrane Contacts and Syncytial Perforations in CA2 Hippocampal Area after Brain Trauma

“…Tight junctions and gap junctions are the most common and well studied connections [11,14]. There are also some recent reports on syncytial connections of neuronal cells [5,9]. Syncytial connections were found in brain hypoxia [7] and in intact brain [15].…”