Reconstructed cells segmented from 3DEM datasets of the oral and aboral intramuscular nerve cords. ©CrookLab
The lab’s newest work on mapping cephalopod nervous systems focuses on the four intramuscular nerve cords that run the length each arm. The function and fine structure of the INCs have received relatively little study.
In this project we combined volume EM and molecular mapping to reveal new information about the anatomy and transcriptional profile of these cords. We reveal that the cords contain a diverse sub-set of cells of different types, including neurons and glia, and that each cord has a clearly demarcated synaptic zone dense with vesicle-filled boutons. We also show that the oblique connectives, which were hypothesized to link INCs on each side of the arm, in fact bypass them completely without sharing fibers.
These data and their associated, freely available datasets are an important resource for the ongoing efforts of multiple lab groups to reveal new insight into the independent evolution of complex nervous systems.
This labor-intensive project was led by three MS students in the lab, John Benedict, Mox Engelman and Meaghan Klos, under the supervision of postdoctoral fellow Dr. Gabrielle Winters-Bostwick.
Our next focus will be the sub-acetabular ganglion, another structure in the arm peripheral nervous system that has received minimal detailed study.