• Courtesy of Ronald Griffith : Mono-transynaptic labeling of premotor interneurons with modified rabies viruses

  • Courtesy of Travis Rotterman: The monosynaptic stretch reflex from Cajal to genetic labeling

  • Courtesy of Travis Rotterman: Motoneuron (blue) and microglia (green) interactions

  • Courtesy of Francisco Alvarez: Renshaw cells

  • Courtesy of Laura Gomez-Perez: Muscle fibers transfected with GFP and/or mCherry

  • Courtesy of Alicia Lane : Genetic intersectional approaches for targeting Renshaw cells

  • Courtesy of Erica Akter: KCC2 regulation in axotomized motoneurons

  • Courtesy of Travis Rotterman: Axotomized motoneurons (blue) and activated microglia (green)

  • Courtesy of Ronald Griffith: AAV1 transfected motoneurons

  • Courtesy of Andre Rivard: Firing properties of genetically-defined classes of interneurons

  • Courtesy of Sarah Fisher (summer student): Muscle spindles

  • Courtesy of Francisco Alvarez: Early embryonic development of the spinal motor system

  • Courtesy of Sarah Fisher (summer student) and Tavishi Chopra: Neuromuscular junctions.

  • Courtesy of Travis Rotterman: Spinal cord microglia

Contact

Francisco J. Alvarez, PhD
Professor and Vice Chair
Department of Cell Biology
Emory University School of Medicine
615 Michael Street
Room 605D
Atlanta, GA 30322-3110
Office:404-727-5139

francisco.j.alvarez@emory.edu

Publications on:
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Research Interests

The Alvarez Lab studies the structure, development and function of spinal motor circuits. Spinal motoneurons innervate skeletal muscle and are the final common path by which our brain executes motor behaviors and interacts with the world around us. Coordinated movement depends on the pattern and timing of motor output from the spinal cord. Think about  the many muscles that need to contract  in  a coordinated manner to place an index finger on the forehead. Motoneurons innervating different muscles need to fire in the appropriate sequence and frequencies to control both timing and strength of contractions in the different muscles moving a joint or a limb. This control is exerted by the neuronal networks of the spinal cord.

These networks are remarkable and allow us to maintain balance and posture, have volitional movements for either kicking a ball or playing the piano and also start rhythmic patterns like locomotion or scratching. Not surprisingly, they are extremely complex and although they have been investigated for over 100 years there is still much to learn about them. The lab is interested in the following questions:

1. How  does this neural network develop in embryo and mature in infants? What can we learn from developmental neurobiology about its organization and the evolution  of locomotor systems in the vertebrate phylogeny? Moreover what goes wrong in these networks in babies with congenital motor deficits?

2. How does this neural network reconfigure when challenged by injury in adult? What role does injury-induced neuroinflammation play in altering the network connections and for what purpose? What is the impact of synaptic plasticity, in particular that of GABA/glycinergic synapses, on motoneurons regenerative programs after they become injured in their axons? 

3. Can knowledge of these neural networks tell us anything about progression of symptoms and triggers during neurodegenerative diseases of the spinal motor system, like Spinal Muscular Atrophy or Amyotrophic Lateral Sclerosis?

Funding and Sponsors

NINDS NSF
Click here for current active grants and fellowships.

Research Highlights and Lab News

11/19/2024

See our latest preprint at: 

https://biorxiv.org/cgi/content/short/2024.11.18.623863v1

QR code: https://connect.biorxiv.org/qr/qr_img.php?id=2024.11.18.623863

GABA and glycine synaptic release on axotomized motoneuron cell bodies promotes motor axon regeneration” by Ryan L. Wood, Paula M. Calvo, William M. McCallum, Arthur W. English, and Francisco J. Alvarez

This paper illustrates the significance for motor axon regeneration of GABA and/or glycine signalling on axotomized adult motoneuron cell bodies after injury-induced KCC2 downregulation. 

 

11/29/2024

Check our recetly paper published in Elife.

Worthy AE, Anderson JT, Lane AR, Gomez-Perez LJ, Wang AA, Griffith RW, Rivard AF, Bikoff JB, Alvarez FJ. Spinal V1 inhibitory interneuron clades differ in birthdate, projections to motoneurons, and heterogeneity. Elife. 2024 Nov 28;13:RP95172. doi: 10.7554/eLife.95172. PMID: 39607843; PMCID: PMC11604222.

https://doi.org/10.7554/eLife.95172.3 

This paper explores heterogeneity within the principal class of genetically defined inhibitory interneurons of the spinal cord that modulate motor output and that are known as V1. It describes how different V1 cell subgroups are generated at different time point during neurogenesis and then shown their different relations with modulation of motoneurons. It further explores in detail the V1 group defined by expression of the transcription factor Foxp2 and relates many of these Foxp2-V1 interneurons to limb control, characterizing some as reciprocal Ia inhibitory interneurons that modulate alternate contractions of flexors and extensors.

 

 

 

Motoneuron 3D Data

3D Motoneuron Data Sharing