Physiology and morphology of the cord stretch receptors of the crayfishCherax destructor

✍ Scribed by Savati, Fiona ;Macmillan, David L.

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 939 KB
• Volume: 265
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402650414

✦ Synopsis

Abstract

The axons of stretch‐sensitive units were located in the isolated nerve cord of the crayfish Cherax destructor. Their physiology and distribution closely resembled that of the tonic and phasic cord stretch receptor (CSR) units of Procambarus clarkii (Grobstein: J. Comp. Physiol., 86:331–348, 1973a), phasic units responding to stretch of the ganglionic cord, and tonic units to stretch of the interganglionic connectives. Removal of the connective tissue sheath did not abolish either response. Small bundles of nerves containing a CSR from the ganglion or connective adjacent to the recording site were backfilled with cobalt. Two common cell types stained, one associated with each physiological result, and we propose that these are the CSRs. Both have cell bodies anteroventrally in the ganglion adjacent to the stretch‐sensitive area and neurites in the same dorsoventral plane as their axons. The neurites of the tonic CSRs are oriented transversely in the neuropile and those of the phasic CSRs longitudinally. We propose that the CSRs are the site of primary stretch activation, that they are either primary sensory neurons with an interneuron‐like structure or interneurons that have acquired a sensitivity to stretch, and that they are activated by connections to cord structures such as those described by Cobb and Heitler (J. Neurocytol., 14:413–426, 1985). We searched for and found no CSRs in the thorax or in the last abdominal ganglion. © 1993 Wiley‐Liss, Inc.