Bimodal septal and cortical triggering and complex propagation patterns of spontaneous waves of activity in the developing mouse cerebral cortex

• Published in: Developmental neurobiology (Hoboken, N.J.) N.J.), 2010-09, Vol.70 (10), p.679-692
• Main Authors: Conhaim, Jay, Cedarbaum, Emily R., Barahimi, Mitra, Moore, Jennifer G., Becker, Matthew I., Gleiss, Helge, Kohl, Christine, Moody, William J.
• Format: Article
• Language: English
• Subjects: alpha -Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors; Animals; Biological Clocks - drug effects; Biological Clocks - physiology; Boundaries; Brain; Calcium imaging; Calcium Signaling - physiology; Calcium signalling; Central nervous system; Cerebral Cortex - embryology; Cerebral Cortex - physiology; Cortex; development; Developmental stages; Evoked Potentials - drug effects; Evoked Potentials - physiology; Female; Functional Laterality - physiology; gamma -Aminobutyric acid A receptors; Mice; Neonates; Nervous system; Neural Pathways - embryology; Neural Pathways - physiology; Neurons - drug effects; Neurons - physiology; Organ Culture Techniques; pacemaker; Pacemakers; picrotoxin; Septal Nuclei - embryology; Septal Nuclei - physiology; septal nucleus; Septum; spontaneous activity; Voltage-Sensitive Dye Imaging - methods
• ISSN: 1932-8451; 1932-846X; 1932-846X
• DOI: 10.1002/dneu.20797

Spontaneous waves of activity that propagate across large structures during specific developmental stages play central roles in CNS development. To understand the genesis and functions of these waves, it is critical to understand the spatial and temporal patterns of their propagation. We recently reported that spontaneous waves in the neonatal cerebral cortex originate from a ventrolateral pacemaker region. We have now analyzed a large number of spontaneous waves using calcium imaging over the entire area of coronal slices from E18‐P1 mouse brains. In all waves, the first cortical region active is this ventrolateral pacemaker. In half of the waves, however, the cortical pacemaker activity is itself triggered by preceding activity in the septal nuclei. Most waves are restricted to the septum and/or ventral cortex, with only some invading the dorsal cortex or the contralateral hemisphere. Waves fail to propagate at very stereotyped locations at the boundary between ventral and dorsal cortex and at the dorsal midline. Waves that cross these boundaries pause at these same locations. Waves at these stages are blocked by both picrotoxin and CNQX, indicating that both GABAA and AMPA receptors are involved in spontaneous activity. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 679–692, 2010