BRAIN OF HORSESHOE CRAB (LIMULUS-POLYPHEMUS) .1. NEUROGLIA

The brain of the horseshoe crab L. polyphemus harbored 3 populations of neuroglial cells, whose distribution and cell details were best appreciated by a combination of Ag impregnation, scanning, and transmission electron microscopy. Stellate astrocytes envelop neurons as satellite cells, permeate the neuropil, and secrete a framework of sustentacular trabeculae throughout the brain. Velate astrocytes are restricted to Kenyon cells, i.e., small association neurons, of which they harbor up to 150/neuroglial cell. The vascular neuroglia was composed of glycogen and mitochondria-laden, interlocked cells that formed an open meshwork in the hemocoelic spaces of the brain. Aside from supportive functions of neuroglia, the vascular neuroglial cells in particular seemed to subserve the role of a metabolic reserve cell for the CNS.