Electron Microscopic Reconstruction of Functionally Identified Cells in a Neural Integrator. Academic Article uri icon

Overview

abstract

  • Neural integrators are involved in a variety of sensorimotor and cognitive behaviors. The oculomotor system contains a simple example, a hindbrain neural circuit that takes velocity signals as inputs and temporally integrates them to control eye position. Here we investigated the structural underpinnings of temporal integration in the larval zebrafish by first identifying integrator neurons using two-photon calcium imaging and then reconstructing the same neurons through serial electron microscopic analysis. Integrator neurons were identified as those neurons with activities highly correlated with eye position during spontaneous eye movements. Three morphological classes of neurons were observed: ipsilaterally projecting neurons located medially, contralaterally projecting neurons located more laterally, and a population at the extreme lateral edge of the hindbrain for which we were not able to identify axons. Based on their somatic locations, we inferred that neurons with only ipsilaterally projecting axons are glutamatergic, whereas neurons with only contralaterally projecting axons are largely GABAergic. Dendritic and synaptic organization of the ipsilaterally projecting neurons suggests a broad sampling from inputs on the ipsilateral side. We also observed the first conclusive evidence of synapses between integrator neurons, which have long been hypothesized by recurrent network models of integration via positive feedback.

publication date

  • July 14, 2017

Research

keywords

  • Eye Movements
  • Neurons
  • Rhombencephalon
  • Zebrafish

Identity

PubMed Central ID

  • PMC5569574

Scopus Document Identifier

  • 85023601004

Digital Object Identifier (DOI)

  • 10.1016/j.cub.2017.06.028

PubMed ID

  • 28712570

Additional Document Info

volume

  • 27

issue

  • 14