# MOTONEURON AXON GUIDANCE IN THE EMBRYONIC LIMB

> **NIH NIH R01** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 1993 · $126,183

## Abstract

It is thought that the proper function of all voluntary motor                   
systems depends on the establishment of highly ordered connections              
between motoneurons and muscles.  The long-term objective of                    
proposed research is to identify mechanisms involved in the                     
formation of specific neuromuscular connections during development              
The embryonic avian spinal cord and hindlimb will be used as a                  
model system.  Previous studies have shown that limb motoneurons                
are specified or have a target identity prior to axon outgrowth and             
that they recognize specific cues in the periphery which guide them             
to correct targets.  Experimental evidence also suggests that these             
cues originate from the LS somatopleural mesoderm, the precursor                
of all limb connective tissues.  Proposed experiments will                      
characterize the role of connective tissue precursor cells in                   
guiding motoneuron axons in the limb.  Studies will define the                  
organization of these cells during axon outgrowth stages and                    
elucidate how and when guidance cues become specified within limb               
connective tissues.  Other experiments 1) will examine the role of              
Schwann cells in limb motoneuron axon outgrowth and 2) will address             
the question of how a motoneuron acquires a target identity prior               
to axon outgrowth.  The methods to be used include embryonic                    
surgical manipulations and interspecies grafting, anatomical and                
electrophysiological techniques for assessing the specificity of                
motoneuron projections, immunohistochemistry, and explant co-                   
culture.  These studies will provide new insights into mechanisms               
of motoneuron and target cell specification and motoneuron axon                 
guidance.  Additionally, they may suggest methods of enhancing axon             
outgrowth following injury.

## Key facts

- **NIH application ID:** 2199674
- **Project number:** 5R01HD025676-05
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **SAM.gov UEI:** MKAGLD59JRL1
- **Principal Investigator:** CYNTHIA LANCE-JONES
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $126,183
- **Award type:** 5
- **Project period:** 1989-07-01 → 1996-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2199674

## Citation

> US National Institutes of Health, RePORTER application 2199674, MOTONEURON AXON GUIDANCE IN THE EMBRYONIC LIMB (5R01HD025676-05). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2199674. Licensed CC0.

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