The inhibitory innervation of the walking leg of the lobsterHomarus americanus

✍ Scribed by Theodore J. Wiens

• Publisher: Springer
• Year: 1990
• Tongue: English
• Weight: 812 KB
• Volume: 167
• Category: Article
• ISSN: 0340-7594
• DOI: 10.1007/bf00192404

✦ Synopsis

1. The extensor, accessory flexor, bender, and closer muscles of the lobster leg were confirmed to be innervated by a single common inhibitory axon branch, denoted CI~, whose activation does not influence the remaining leg muscles in most autotomized limbs.

2. The flexor, stretcher, reductor, and rotator muscles share inhibition from a second common inhibitory axon branch, CIF, whose activation in most autotomized limbs does not affect CIE'S target muscles. The stretcher muscle additionally receives a separate inhibitory innervation from the specific stretcher inhibitor, SI.

3. In whole, non-autotomized limbs that retain the most proximal segments (the coxa and the basis), CI E and CI F were shown to be proximally diverging branches of a single common inhibitory axon (CI), as evidenced by the activation of one branch through antidromic spikes in the other.

4. The opener muscle also receives CI, usually but not invariably from the CI E branch. The well-known specific opener inhibitor, OI, produces a distinctly different additional class of ijp's in opener muscle fibers.

5. Thus, in the lobster as in other decapods, a single common inhibitory neuron, CI, innervates all leg muscles; two specific inhibitors to the stretcher and opener muscles are the only other known inhibitory motoneurons to the leg.