SYNAPTIC TRANSMISSION AND ITS RELATION TO SURFACE CHEMISTRY OF NERVE CELLS.
Abstract
Research was conducted on two problems: (1) In the frog, certain muscles normally contain slow as well as fast muscle fibers, and exhibit a composite mechanical response. It was found following denervation of these muscles and during nerve regeneration that the sustained component of the mechanical response disappears, without appreciable change in the fast component. Further experiments revealed that this transformation is not related to the transmission of nervous impulses across the neuromuscular junction. Also, electron microscopy of transformed muscles reveals slow muscle fibers in normal proportion, and with intact internal (fibrillar) structure. Accordingly it is concluded that a 'humoral' or 'trophic' agent released by the degenerating or regenerating nerve is capable of modification of membrane structure of slow muscle fibers in the frog to prevent excitation and the ensuing mechanical contraction. (2) In the cerebral cortex of the cat, analysis was performed of the 'equivalent dipole length' of the dipoles formed between current sources and sinks on cortical neurons. Because synapses on these cells act as current sources, and the circuit is closed through passive membrane, presumably around the axon hillock, this approach gives an indication of the localization of synapses relative to the axon hillock and the cell body. Dipoles of 0.5 - 2.5 mm pole separation were found in the waking animal. During sleep pole separation increased to 1.0 - 4.0 mm. It was also found that different components of visual evoked potentials are generated by synapses at significantly different locations on the neuron. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 15, 1968
- Accession Number
- AD0666694
Entities
People
- Rafael Elul
Organizations
- University College London