EurekaMag.com logo
+ Site Statistics
References:
48,253,228
Abstracts:
22,798,842
+ Resolve Accession
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
Submit PDF Full TextSubmit PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Extension and retraction of axonal projections by some developing neurons in the leech depends upon the existence of neighboring homologues. II. The AP and AE neurons


, : Extension and retraction of axonal projections by some developing neurons in the leech depends upon the existence of neighboring homologues. II. The AP and AE neurons. Journal of Neurobiology 18(3): 295-313

To assess the generality of our previous finding (Gao and Macagno, 1987) that segmental homologues play a role in the establishment of the pattern of axonal projections of the heart accessory HA neurons, we have extended our studies to two other identified leech neurons: the anterior pagoda (AP) neurons and the annulus erector (AE) motor neurons. Bilateral pairs of AP neurons are found in the first through the twentieth segmental ganglia (SG1 through SG20) of the leech ventral nerve cord. All AP neurons initially extend axonal projections to the contralateral periphery as well as longitudinal projections along the contralateral interganglionic connective nerves toward anterior and posterior neighboring ganglia. Although the peripheral projections are maintained by all AP neurons throughout the life of the animal, the longitudinal projections disappear in all but two segments: the AP neurons in SG1 maintain their anterior projections and extend them into the head ganglion, and those in SG20 maintain their posterior projections and extend them into SG21 and the tail ganglion. When single AP neurons are deleted anywhere along the nerve cord before processes begin to atrophy, however, the longitudinal projections are retained by their ipsilateral homologues in adjacent ganglia. The rescued processes appear to take over the projections of the deleted neurons. In cases where two or more AP neurons on the same side of the nerve cord are deleted from adjacent ganglia, a contralateral homologue sometimes extends projections to the periphery ipsilaterally or on both sides. We obtained similar results when we deleted single AE neurons from midbody ganglia. Thus, our experiments with three different identified neurons consistently show that the initial pattern of projections is the same in all ganglia, but that the existence of homologues in adjacent ganglia leads to the pruning of some of the initial projections. A consequence of this homologue-dependent process retraction is that neurons normally lacking neighboring homologues will have patterns of projections different from those neurons that do have such neighbors. Process loss by the HA, AP, and AE neurons may be the result either of competition for targets, inputs, or growth factors or of direct interactions among homologous cells.

Order PDF Full Text

Close
Close

Click here to order any other PDF Full Text


Accession: 005432783

PMID: 3298543

DOI: 10.1002/neu.480180305

Download PDF Full Text: Extension and retraction of axonal projections by some developing neurons in the leech depends upon the existence of neighboring homologues. II. The AP and AE neurons


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Other references

Simons, M., 1995: Dutch doctors to tighten rules on mercy killings. New York Times on the Web: A3-A3

Taneeru, S.; Guttikonda, V.R.; Yeluri, S.; Madala, J., 2014: Granular cell ameloblastoma of jaw - Report of a case with an emphasis on its characterization. Ameloblastoma is a neoplasm of odontogenic epithelium, especially of enamel organ-type tissue that has not undergone differentiation to the point of hard tissue formation. It accounts for approximately 10% of all tumors originating from gnathic bo...

MERRILD-HANSEN, B., 1954: Resection in cardiac diverticulum. Ugeskrift for Laeger 116(44): 1563-1564

Posadzki, P.; Smith, T.O.; Lizis, P., 2010: Lomi Lomi as a massage with movements: a conceptual synthesis?. This article narratively reviews the evidence of 2 therapeutic modalities, massage and passive movement. The authors suggest that these 2 treatment techniques may be combined as 1 treatment to be used in a variety of clinical settings. We present...

Powell, LE., 1973: Factors influencing agonistic behaviour and social organization in the orangespotted sunfish, Lepomis humilis (Girard). Dissertation Abstr lnt, 33B12(i): 6144-6145

Liu, W.; He, F.; Shi, G., 2015: Success rates and prognosis of heart valvuloplasty and valve replacement performed for elderly patients. To analyze the success rates and prognosis of heart valvuloplasty and valve replacement for elderly patients, and to provide clinical evidence. A total of 1240 patients who received heart valve surgeries in our hospital from June 2004 to October 2...

Fearing, D.A.; Banks, J.; Wilson, D.; Hillis, P.H.; Campbell, A.T.; Parsons, S.A., 2004: NOM control options: the next generation. Seasonal periods of high rainfall have been shown to cause elevated natural organic matter (NOM) loadings at treatment works. These high levels lead to difficulties in removing sufficient NOM to meet trihalomethane (THM) standards, and hence bette...

Reynolds, C.H.; Dalziel, K., 1979: Factors affecting coenzyme binding and subunit interactions in glyceraldehyde 3 phosphate dehydrogenase ec 1.2.1.12. There is no evidence, at pH 9.4, of negative cooperativity in the binding of NAD+ or NADH to rabbit muscle glyceraldehyde-3-phosphate dehydrogenase (D-glyceraldehyde-3-phosphate:NAD+ oxidoreductase (phorphorylating), EC 1.2.1.12) nor in the bindin...

McCormack, J.J.; Marquez, V.E.; Liu, P.S.; Vistica, D.T.; Driscoll, J.S., 2010: Inhibition of cytidine deaminase by 2-oxopyrimidine riboside and related compounds. Biochemical Pharmacology 29(5): 830-832

Villenas, F.; Palma, S., 2006: Sagitta chilensis nueva especie de quetognato en fiordos australes chilenos (Chaetognatha, Aphragmophora, Sagittidae). A new species of Chaetognatha, Aphragmophora, is described for the first time for the Chilean fjords. The specimens were collected between the mouth of the Guafo and Pulluche channel, in November 2002. Noteworthy morphological differences with oth...