Syncytial interneuronal connections in the sensorimotor cortex and caudate nucleus were studied in 20 rats of 14–22 days of intrauterine development. While the development of glial processes was extremely weak, many neuron bodies and their processes were in direct contact with each other. Contacting membranes formed extended and punctate contacts reminiscent of gap and tight junctions. As a result, intercellular clefts showed varicose-type deformation. Hardly detectable membrane pores were seen around contacts, which increased in size to large perforations. The margins of perforations formed a rounded structure consisting of the fused plasmalemmas of adjacent cells. Areas of paired membranes between perforations were fragmented, increasing the number of residual bodies until the neurons fused completely, forming a neuroplasm common to the contacting cells. These results lead to the conclusion that neuron fusion in the cerebral cortex and brainstem nuclei of vertebrates can occur not only in pathology, but also in normal animals at the intrauterine stage of development.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
N. N. Bogolepov, N. I. Pavlovskaya, and N. I. Yakovleva, “Ultrastructure of contacts between paired neurons during the posthypoxic period,” Arkh. Anat., 79, No. 9, 15–24 (1980).
N. N. Bogolepov, N. I. Yakovleva, L. E. Frumkina, and S. K. Koroleva, “Different types of nonspecific intercellular contacts in the developing rat brain,” Arkh. Anat., 40, No. 2, 45–53 (1986).
V. F. Ivanov, “Multinucleate cells (formation, structure, biological significance),” Arkh. Anat., 87, No. 12, 80–86 (1984).
A. A. Paltsyn, E. G. Kolokolchikova, N. B. Konstantinova, et al., “Formation of heterokarya as a means of regenerating neurons in postischemic damage to the cerebral cortex in rats,” Byull. Eksperim. Biol. Med., 146, No. 10, 407–410 (2008).
A. A. Paltsyn, N. B. Konstantinova, G. A. Romanov, et al., “The role of cell fusion in the physiological and reparative regeneration of the cerebral cortex,” Byull. Eksperim. Biol., 148, No. 11, 580–583 (2009).
N. V. Samosudova, N. P. Larionova, and P. L. Chailakhyan, “Pathological fusion of frog cerebellar cells in the presence of L-glutamate in vivo,” Dokl. Ros. Akad. Nauk., 336, No. 3, 406–409 (1994).
V. V. Semchenko, N. N. Bogolepov, and S. S. Stepanov, “Synaptic plasticity of the neocortex in white rats in diffuse-focal brain damage,” Morfologiya, 128, No. 4, 76–81 (2005).
O. S. Sotnikov, L. I. Archakova, S. A. Novakovskaya, and I. A. Solovieva, “The question of the syncytical connections of neurons in pathology,” Byull. Eksperim. Biol., 147, No. 2, 207–210 (2009).
O. S. Sotnikov, S. A. Novakovskaya, and I. A. Solovieva, “Syncytial perforations of neuronal membranes in human embryos,” Ontogenez, 42, No. 1, 42–52 (2011).
A. B. Uzdenskii, “Controlled necrosis,” Biol. Membrany, 27, No. 1, 7–17 (2010).
N. E. Yarygin and V. N. Yarygin, Pathogenetic and Adaptive Changes in Neurons [in Russian], Meditsina, Moscow (1973).
J. B. Ackman, F. Siddiqi, R. S. Walikonis, and J. J. LoTurco, “Fusion of microglia with pyramidal neurons after retroviral infection,” J. Neurosci., 26, No. 44, 11413–11422 (2006).
A. Aguzzi, E. F. Wagner, K. O. Netzer, et al., “Human foamy virus proteins accumulate in neurons and induce multinucleated giant cells in the brain of transgenic mice,” Am. J. Pathol., 142, No. 4, 1061–1071 (1993).
M. Alvarez-Dolado, R. Pardal, J. M. Garcia-Verdugo, et al., “Fusion of bone marrow-derived cells with Purkinje neurons, cardiomyocytes and hepatocytes,” Nature, 425, No. 6961, 968–973 (2003).
L. I. Archakova, O. S. Sotnikov, S. A. Novakovskaya, et al., “Syncytial cytoplasmic anastomoses between neurites in caudal mesenteric ganglion cells,” Neurosci. Behav. Physiol., 40, No. 4, 447–450 (2010).
J. S. Bae, H. S. Han, D. H. Youn, et al., “Bone marrow-derived mesenchymal stem cells promote neural networks with functional synaptic transmission after transplantation into mice with neurodegeneration,” Stem Cells, 25, No. 5, 1307–1316 (2007).
J. D. Marotti, S. L. Savitz,W. K. Kim, et al., “Cerebral amyloid angiitis processing to generalized angiitis and leucoencephalitis,” Neuropathol. Appl. Neurobiol., 33, No. 4, 474–479 (2007).
N. M. Paramonova and O. S. Sotnikov, “Cytoplasmic syncytial connections between neuron bodies in the CNS of adult animals,” Neurosci. Behav. Physiol., 40, No. 1, 73–77 (2010).
R. S. Santander, G. M. Cuadrado, and M. R. Sáez, “Exceptions to Cajal’s neuron theory: communicating synapses,” Acta Anat., 132, 74–76 (1988).
O. S. Sotnikov, V. V. Malashko, and G. I. Rybakova, “Fusion of nerve fibers,” Dokl. Biol. Sci., 410, 361–363 (2006).
O. S. Sotnikov, V. V. Malashko, and G. I. Rybakova, “Syncytial coupling of neurons in tissue culture and early ontogenesis,” Neurosci. Behav. Physiol., 38, No. 4, 323–331 (2008).
O. S. Sotnikov, N. M. Paramonova, and L. I. Archakova, “Ultrastructural analysis of interneuronal syncytial perforations,” Cell Biol. Int., 34, No. 4, 361–364 (2009).
Author information
Authors and Affiliations
Corresponding author
Additional information
Translated from Morfologiya, Vol. 139, No. 2, pp. 18–21, March–April, 2011.
Rights and permissions
About this article
Cite this article
Sotnikov, O.S., Frumkina, L.E., Novakovskaya, S.A. et al. Fusion of Brain Neurons in Rat Embryos. Neurosci Behav Physi 42, 594–597 (2012). https://doi.org/10.1007/s11055-012-9606-y
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11055-012-9606-y