Sprouting and functional regeneration of an identified neuron in helisoma

Murphy, A. D.; Kater, Stanley B.

doi:10.1016/0006-8993(80)90974-9

Cited by 88 publications

(58 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No evidence of neuron death as a result of target removal was observed in the present or related studies (Murphy and Kater, 1980a;Stamler et al, unpublished). The ability of molluscan motoneurons to survive without targets may be a property common to invertebrate neurons.…”

Section: Physiological Properties Of Motoneurons After Target Separationcontrasting

confidence: 45%

“…Helisoma neurons exhibit directed growth following axotomy when peripheral target organs are present or when nerve roots are intact , 1980a, 1980b. Such regenerative growth leads to the restoration of normal Here we report on the physiological condition of the isolated ganglia, and we will draw parallels to the effects of axotomy observed in mammals and insects.…”

Section: Discussionmentioning

confidence: 86%

“…(Purves, 1977;Jacobson, 1978;Lund, 1978). Isolated molluscan ganglia, however, survive indefinitely in the absence of normal targets (Murphy and 532 BULLOCH, KATER, AND MURPHY Kater, 1980a), and here we report both the loss and subsequent restoration of central chemical synapses without target reinnervation.…”

Section: Introductionmentioning

confidence: 78%

See 2 more Smart Citations

Connectivity changes in an isolated molluscan ganglion during in vivo culture

1980

View full text Add to dashboard Cite

SUMMARYThe stability of neuronal connections in the isolated buccal ganglia of Helisoma trivolvis was examined during in vivo culture for periods up to one month. After 4-8 days the characteristic IPSP input to protractor motoneurons (PMNs) was either abolished or reduced in efficacy. This is apparently due to reduced efficacy of chemical synapses, since the input resistance and resting potential of the motoneurons is unchanged and a fraction of spike-evoked IPSPs from premotor neurons (cyberchrons) onto PMNs was absent. PMNs lacking IPSP input nevertheless exhibit vigorous cyclical bursts of action potentials driven by electrical EPSPs. The IPSP of PMNs showed partial or full restoration after 14-32 days of culture despite the lack of reinnervation of normal targets. Existing electrical synapses were apparently more stable during culture, but electrical connections between cyberchrons and PMNs were strengthened. Probably because of the reinforcement of these electrical synapses, regenerative cycles of activity in both cyberchrons and PMNs may often be initiated by brief stimulation of a single PMN in cultured ganglia. This is in marked contrast to normal ganglia in which PMNs possess a limited ability to generate such activity. It is concluded that isolation of the buccal ganglia results in a predictable, functional alteration of its neuronal circuitry. Such a perturbation of connectivity indicates that a significant degree of plasticity can be exhibited by adult molluscan neurons.

show abstract

Section: Physiological Properties Of Motoneurons After Target Separationcontrasting

confidence: 45%

Section: Discussionmentioning

confidence: 86%

See 1 more Smart Citation

Connectivity changes in an isolated molluscan ganglion during in vivo culture

1980

View full text Add to dashboard Cite

show abstract

“…After procedures 2-5, the axons of neuron B4 regenerated in the form of bundles of neurites, as described by Murphy and Kater (1980a). Neurite outgrowth was already evident 1-2 days postoperation, whereas after 2-3 days the longest neurites approached the salivary glands.…”

Section: Time Course Of Neurite Outgrowth and Target Reinnervationmentioning

confidence: 96%

“…Many invertebrate neurons with multiple axons also regenerate all their severed axons, e.g., in Helisoma (Murphy and Kater, 1980a;Bulloch et al, 1980;Cohan et al, 1987;Bulloch, 1985), and in the leech (Macagno et al, 1985).…”

Section: Introductionmentioning

confidence: 99%

Axonal regeneration of an identified Helisoma neuron depends on the site of axotomy

Kruk¹,

Bulloch²

1992

J of Neuroscience Research

View full text Add to dashboard Cite

Axotomy of molluscan neurons usually results in axonal regeneration. In this study, we tested the axotomy response of an identified neuron of the pond snail Helisoma trivolvis (buccal neuron 4, B4). This neuron has two primary axonal branches, the ipsilateral axon and the contralateral axon, each innervating one of the paired salivary glands. The ipsilateral axon projects via the ipsilateral esophageal nerve trunk whereas the contralateral axon crosses both buccal ganglia and projects via the contralateral esophageal nerve trunk. We tested various procedures of axotomy: injury to one axon or both axons, close to the ganglion or more distal. Surprisingly, we found that proximal axotomy of the ipsilateral axon was not usually followed by axonal regeneration. By contrast, all other procedures of axotomy (e.g., distal ipsilateral, or proximal bilateral) resulted in robust axonal regeneration and target reinnervation. Thus, in this preparation, axotomy may or may not result in axonal regeneration, depending on the site(s) of axotomy. To the best of our knowledge, such a differential result has not yet been found in any other preparation. We conclude that axotomy is not always a sufficient condition for axonal regeneration of molluscan neurons. We hypothesize that a damaged axonal stump may be a necessary condition for the initiation of regeneration. An alternative hypothesis is that neurite outgrowth is inhibited in normal mature neurons by a target-derived factor. This hypothetical factor would be transported retrogradely, but not anterogradely, along axons.

show abstract

Axonal regeneration in the central nervous system ofAplysia californica determined by anterograde transport of biocytin

et al. 1999

View full text Add to dashboard Cite

Rhythmic biting, a component of consummatory feeding behavior in the sea hare Aplysia californica, is eliminated following bilateral cerebral–buccal connective (CBC) crushes and recovers within 14 days postlesion. To assess axonal regeneration after CBC lesions, we used biocytin backfills of CBCs followed by fluorescence labeling with streptavidin‐lissamine rhodamine. Anterograde transport of biocytin showed up to 1 mm of outgrowth by regenerating axons at 3 days postlesion. At 7 days postlesion, the regenerated axons approached or had entered the ipsilateral buccal neuropil and exhibited numerous varicosities; the average rate of axonal growth was 326 μm/day for the longest, most rapidly growing axons labeled in the CBC. The number of varicosities on labeled axons, suggestive of intercellular interactions, was increased dramatically at all times postlesion. At 14 and 20 days postlesion, regenerated axons branched extensively in the ipsilateral buccal neuropil, entered the contralateral buccal neuropil, and entered peripheral nerves on both sides of the midline. At these later times postlesion, some labeled axons encircled unlabeled buccal cell bodies and exhibited branches containing numerous varicosities, indicative of axosomatic contacts. Some regenerating axons were observed in the sheath of the CBC, but the vast majority of labeled axons remained confined to the connective core, as in control preparations. The bilateral projections within the buccal ganglia of labeled cerebral‐to‐buccal axons and the large number of varicosities present on these processes are indicative of regenerating axons and synapses that likely contribute to the functional recovery of rhythmic biting. J. Comp. Neurol. 406:476–486, 1999. © 1999 Wiley‐Liss, Inc.

show abstract

Sprouting and functional regeneration of an identified neuron in helisoma

Cited by 88 publications

References 21 publications

Connectivity changes in an isolated molluscan ganglion during in vivo culture

Connectivity changes in an isolated molluscan ganglion during in vivo culture

Axonal regeneration of an identified Helisoma neuron depends on the site of axotomy

Axonal regeneration in the central nervous system ofAplysia californica determined by anterograde transport of biocytin

Contact Info

Product

Resources

About