Clustered Thalamocortical Input on to Layer 5 Pyramidal Neurons

Jong Cheol Rah(1)
Jong Cheol Rah
Korea Brain Research Institute, Korea
11:25~12:10, November 21st, 2014

Abstract :

The subcellular locations of synapses on pyramidal neurons strongly influence dendritic integration and synaptic plasticity. Despite this, there is little quantitative data on spatial distributions of specific types of synaptic input. Here we use array tomography (AT), a high-resolution optical microscopy method, to examine thalamocortical (TC) input onto layer 5 pyramidal neurons. We first verified the ability of AT to identify synapses using parallel electron microscopic analysis of TC synapses in layer 4. We then use large-scale array tomography (LSAT) to measure TC synapse distribution on L5 pyramidal neurons in a 1.00×0.83×0.21mm 3 volume of mouse somatosensory cortex. We found that TC synapses primarily target basal dendrites in layer 5, but also make a considerable input to proximal apical dendrites in L4, consistent with previous work. Our analysis further suggests that TC inputs are biased toward certain branches and, within branches, synapses show significant clustering with an excess of TC synapse nearest neighbors within 5–15µm compared to a random distribution. Thus, we show that AT is a sensitive and quantitative method to map specific types of synaptic input on the dendrites of entire neurons. We anticipate that this technique will be of wide utility for mapping functionally-relevant anatomical connectivity in neural circuits.


Research Interests

  • Physiology of synaptic transmission and dendritic integration
  • Experience-dependent Synaptic and Circuit Plasticity in the central nervous system


Awards and Honors

  • 2008. 11 – 2012. 8 : Howard Hughes Medical Institute: Visiting Scientist Program
  • 2005. 8 – 2009. 1 : NINDS Intramural Visiting Research Training Awards
  • 2002. 2 – 2004. 1 : Max-Planck fellowship for foreign PhD student
  • 2001. 11 – 2002. 2 : BK21 Exchange Studentship- Imperial College London
  • 2000. 8 – 2001. 2 : Brain Korea 21 (BK 21) scholarship
  • 2000. 11 – 2001. 1 : BK21 Exchange Studentship- Imperial College London
  • 2001. 8 : Best Graduate Student Award from Brain Korea 21