The polysialylated form of the neural cell adhesion molecule (PSA-NCAM) is expressed in a subpopulation of mature cortical interneurons characterized by reduced structural features and connectivity

• Published in: Cerebral cortex (New York, N.Y. 1991) N.Y. 1991), 2011-05, Vol.21 (5), p.1028-1041
• Main Authors: Gómez-Climent, María Ángeles, Guirado, Ramón, Castillo-Gómez, Esther, Varea, Emilio, Gutierrez-Mecinas, María, Gilabert-Juan, Javier, García-Mompó, Clara, Vidueira, Sandra, Sanchez-Mataredona, David, Hernández, Samuel, Blasco-Ibáñez, José Miguel, Crespo, Carlos, Rutishauser, Urs, Schachner, Melitta, Nacher, Juan
• Format: Article
• Language: English
• Subjects: Animals; Cell Differentiation - genetics; Cell Shape - genetics; Cerebral Cortex - metabolism; Cerebral Cortex - pathology; Interneurons - metabolism; Interneurons - pathology; Male; Neural Cell Adhesion Molecule L1 - biosynthesis; Neural Cell Adhesion Molecule L1 - genetics; Neural Inhibition - genetics; Neural Pathways - metabolism; Neural Pathways - pathology; Neural Pathways - physiopathology; Neurogenesis - genetics; Neuronal Plasticity - genetics; Rats; Rats, Sprague-Dawley; Sialic Acids - biosynthesis; Sialic Acids - genetics
• ISSN: 1047-3211; 1460-2199
• DOI: 10.1093/cercor/bhq177

Principal neurons in the adult cerebral cortex undergo synaptic, dendritic, and spine remodeling in response to different stimuli, and several reports have demonstrated that the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) participates in these plastic processes. However, there is only limited information on the expression of this molecule on interneurons and on its role in the structural plasticity of these cells. We have found that PSA-NCAM is expressed in mature interneurons widely distributed in all the extension of the cerebral cortex and have excluded the expression of this molecule in most principal cells. Although PSA-NCAM expression is generally considered a marker of immature neurons, birth-dating analyses reveal that these interneurons do not have an adult or perinatal origin and that they are generated during embryonic development. PSA-NCAM expressing interneurons show reduced density of perisomatic and peridendritic puncta expressing different synaptic markers and receive less perisomatic synapses, when compared with interneurons lacking this molecule. Moreover, they have reduced dendritic arborization and spine density. These data indicate that PSA-NCAM expression is important for the connectivity of interneurons in the adult cerebral cortex and that its regulation may play an important role in the structural plasticity of inhibitory networks.