J Physiol Society Membership
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


J Physiol Vol 241, Issue 2 pp 389-405
Copyright © 1974 by The Physiological Society
This Article
Right arrow Full Text (PDF)
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ito, F.
Right arrow Articles by Kuroda, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ito, F.
Right arrow Articles by Kuroda, H.

Structural and functional asymmetries of myelinated branches in the frog muscle spindle

F. Ito, N. Kanamori and H. Kuroda

1. Most of the axons innervating single-type muscle spindles in the frog sartorius muscle divide into myelinated branches at a node; one of the branches subdivides (Bs) and the other does not (Bn).

2. Electrical responses at the afferent nerve terminal of the isolated spindles were recorded extracellularly and intracellularly with micro-electrodes, concurrently with the terminal responses by the paraffin gap method.

3. By recording spontaneous orthodromic and provoked antidromic impulses and by stimulating the nerve terminals with micro-electrodes and inactivating the terminals with micro-application of potassium ion, it was deduced that propagated and abortive spikes are almost always generated at the terminal of Bn (Tn), not at the terminals of Bs (Ta and Tb).

4. The site of impulse initiation, as determined in (3), was found, after measurement of the lengths of the myelinated branches in each preparation, to be essentially the terminal nearest the parent axon.

5. Selective inactivation of Tn by far-ultra-violet light removed both propagated and abortive spikes. Both types of spikes survived after irradiation of Ta and Tb, although the relationship between spike frequency and spindle stretch was altered. The same results were obtained after transection of the branches with a laser microbeam.




This article has been cited by other articles:


Home page
J. Neurophysiol.Home page
M. P. Mileusnic and G. E. Loeb
Mathematical Models of Proprioceptors. II. Structure and Function of the Golgi Tendon Organ
J Neurophysiol, October 1, 2006; 96(4): 1789 - 1802.
[Abstract] [Full Text] [PDF]




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1974 The Physiological Society.