axon cap

10 examples (0.02 sec)
  • Finally, the surface of the axon cap is covered with a cap wall composed of several layers of astrocyte-like glial cells.
  • The high resistance of this axon cap contributes to the typical shape of the Mauthner cell field potential (see below).
  • The fibers of these neurons are located in the axon cap, and they receive inputs from both ipsilateral and contralateral Mauthner cells.
  • The positive components of the field potential are strongest in the axon cap, reaching amplitudes of 45 mV in adult goldfish.
  • The Mauthner cell axon hillock is surrounded by a dense formation of neuropil, called the Axon cap.
  • In its most advanced form the axon cap consists of a core, immediately adjacent to the Mauthner cell axon, and containing a network of very thin unmyelinated fibers, and a peripheral part.
  • Evolutionarily, the axon cap is a more recent development than the Mauthner cell itself, so some animals, such as lampreys and eels, while having functional Mauthner cells, don't have axon cap at all, while some other animals, such as amphibia and lungfish, do have a very simplified version of it.
  • When the region of the PHP cell axon outside the axon cap depolarizes, the influx of positive charge into the cell through voltage gated sodium channels is accompanied by a passive outflow of current from the PHP cell axon into the region bound by the axon cap.
  • This peripheral part contains the large unmyelinated fibers of the PHP neurons (see below) that mediate the inhibitory feedback to the Mauthner cell; the Mauthner cell itself also sends small dendrites from its axon hill to the peripheral part of the axon cap.
  • The action of PHP neurons onto the Mauthner cells is mediated by electrical, and not chemical effects: the outward currents generated by the action potentials in axon cap fibers flow inward across the Mauthner cell axon hillock and hyperpolarize it.