This week we profile a recent publication in Neuron from Drs. Jonathan Ting (left)
and Brian Kalmbach (right) at the Allen Institute for Brain Science.
Can you provide a brief overview of your lab’s current research focus?
The aim of our work is to systematically explore the diverse cell types of the human neocortex using an integrated electrophysiological, morphological, and molecular profiling approach. We are building a comprehensive classification of cell types in the human neocortex with the goal of understanding how these component parts contribute to brain function in health and disease.
What is the significance of the findings in this publication?
Human and rodent brains are clearly different in terms of size and complexity. Yet, how the constituent parts of rodent versus human brain differ is unclear. We provide evidence that the physiological properties of human and mouse supragranular pyramidal neurons differ substantially in part because of differences in the expression of an ion channel, the h-channel. Consequently, human and mouse supragranular pyramidal neurons integrate synaptic input differently. For example, human neurons prefer synaptic input containing frequencies associated with learning and attention (theta-band frequencies). Our results also indicate that the expression of h-channels in human supragranular pyramidal neurons may represent an evolutionary adaptation for very large pyramidal neurons in the human neocortex.
What are the next steps for this research?
Given the unique biophysical properties of the pyramidal neurons in the deepest part of the supragranular cortex, we hope to further examine the abundance and distribution of these neurons in the human neocortex, and to link gene expression to function for the various other genes that we have identified as differentially expressed or enriched in these neurons.
