Title:
Structured spike series specify gene expression patterns for olfactory circuit formation

 

Speaker:
Haruki Takeuchi
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan

 

Abstract:

Neural circuits emerge through the interplay of genetic programming and activity-dependent process. During the development of mouse olfactory map, axons segregate into distinct glomeruli in an olfactory receptor (OR)-dependent manner. ORs generate a combinatorial code of axon-sorting molecules, whose expression is regulated by neural activity. However, how neural activity induces OR-specific expression patterns of axon-sorting molecules remains unclear. Here we revealed that the temporal patterns of spontaneous neuronal spikes were not spatially-organized, but were correlated with the OR types. Receptor substitution experiments demonstrated that ORs determine spontaneous activity patterns. Moreover, optogenetically differentiated patterns of neuronal activity induced specific expression of the corresponding axon-sorting molecules and regulated axonal segregation. Thus, OR-dependent temporal patterns of spontaneous activity play instructive roles in generating the combinatorial code of axon-sorting molecules during olfactory map formation.

 

References:

1. ^※Nakashima A, ^※Ihara N. et al. “Structured spike series specify gene expression patterns for olfactory circuit formation” Science (article), DOI: 10.1126/science.aaw5030 (2019)
2. Ihara N, Nakashima A. et al. “Differential expression of axon-sorting molecules in mouse olfactory sensory neurons” Eur. J. Neurosci Vol.44, 1998-2003 (2016)
3. ^※Nakashima A, ^※Takeuchi H. et al. “Agonist-independent GPCR activity regulates Anterior-Posterior targeting of olfactory sensory neurons.”　Cell,　Vol.154 1314-1325 (2013)
4. ^※Takeuchi H, ^※Inokuchi K. et al. “Sequential Arrival and Graded Secretion of Sema3F by Olfactory Neuron Axons Specify Map Topography at the Bulb.” Cell, Vol.141 1056-1067 (2010)
5. ^※Serizawa S, ^※Miyamichi K, ^※Takeuchi H. et al. “A Neuronal Identity Code for the Odorant Receptor-Specific and Activity-Dependent Axon Sorting.” Cell, Vol.127 1057-1069 (2006) ※ equally contributed