Limits...
Visualization of Sensory Neurons and Their Projections in an Upper Motor Neuron Reporter Line.

Genç B, Lagrimas AK, Kuru P, Hess R, Tu MW, Menichella DM, Miller RJ, Paller AS, Özdinler PH - PLoS ONE (2015)

Bottom Line: Our findings corroborate previous studies, and suggest that more than five months is required for significant skin denervation.Crossing UCHL1-eGFP with hSOD1G93A mice generated hSOD1G93A-UeGFP reporter line of amyotrophic lateral sclerosis, and revealed sensory nervous system defects, especially towards disease end-stage.Our studies not only emphasize the complexity of the disease in ALS, but also reveal that UCHL1-eGFP reporter line would be a valuable tool to visualize and study various aspects of sensory nervous system development and degeneration in the context of numerous diseases.

View Article: PubMed Central - PubMed

Affiliation: Davee Department of Neurology and Clinical Neurological Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States of America.

ABSTRACT
Visualization of peripheral nervous system axons and cell bodies is important to understand their development, target recognition, and integration into complex circuitries. Numerous studies have used protein gene product (PGP) 9.5 [a.k.a. ubiquitin carboxy-terminal hydrolase L1 (UCHL1)] expression as a marker to label sensory neurons and their axons. Enhanced green fluorescent protein (eGFP) expression, under the control of UCHL1 promoter, is stable and long lasting in the UCHL1-eGFP reporter line. In addition to the genetic labeling of corticospinal motor neurons in the motor cortex and degeneration-resistant spinal motor neurons in the spinal cord, here we report that neurons of the peripheral nervous system are also fluorescently labeled in the UCHL1-eGFP reporter line. eGFP expression is turned on at embryonic ages and lasts through adulthood, allowing detailed studies of cell bodies, axons and target innervation patterns of all sensory neurons in vivo. In addition, visualization of both the sensory and the motor neurons in the same animal offers many advantages. In this report, we used UCHL1-eGFP reporter line in two different disease paradigms: diabetes and motor neuron disease. eGFP expression in sensory axons helped determine changes in epidermal nerve fiber density in a high-fat diet induced diabetes model. Our findings corroborate previous studies, and suggest that more than five months is required for significant skin denervation. Crossing UCHL1-eGFP with hSOD1G93A mice generated hSOD1G93A-UeGFP reporter line of amyotrophic lateral sclerosis, and revealed sensory nervous system defects, especially towards disease end-stage. Our studies not only emphasize the complexity of the disease in ALS, but also reveal that UCHL1-eGFP reporter line would be a valuable tool to visualize and study various aspects of sensory nervous system development and degeneration in the context of numerous diseases.

No MeSH data available.


Related in: MedlinePlus

Sensory axons are eGFP+.(A-B) eGFP expression in the axons of sensory branch of the femoral nerve (FS, arrows) makes it visible in vivo. FM: femoral nerve motor branch (arrowheads). (C) DRG axons innervating the dorsal and ventral horn of the spinal cord are labeled by eGFP (arrows). Spinal motor neurons (SMN) in the ventral horn are also GFP+ (arrowhead). (D) Cross-sections of the dorsal root show complete overlap between neurofilament-H (NF-H) labeled axons and eGFP expression in the UCHL1-eGFP mice, and there is no GFP in the WT mice. Scale bars A,B 1 mm; C 250 μm; D 50 μm; D inset 20 μm.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4519325&req=5

pone.0132815.g003: Sensory axons are eGFP+.(A-B) eGFP expression in the axons of sensory branch of the femoral nerve (FS, arrows) makes it visible in vivo. FM: femoral nerve motor branch (arrowheads). (C) DRG axons innervating the dorsal and ventral horn of the spinal cord are labeled by eGFP (arrows). Spinal motor neurons (SMN) in the ventral horn are also GFP+ (arrowhead). (D) Cross-sections of the dorsal root show complete overlap between neurofilament-H (NF-H) labeled axons and eGFP expression in the UCHL1-eGFP mice, and there is no GFP in the WT mice. Scale bars A,B 1 mm; C 250 μm; D 50 μm; D inset 20 μm.

Mentions: We next investigated if eGFP was present in the axons, and whether de novo fluorescence would be strong enough to visualize axon tracts and individual fibers. We find that in the UCHL1-eGFP mice eGFP expression is present not only in the cell bodies (Fig 2A), but also in the peripheral (Fig 3A and 3B) and central (Fig 3C) projections of the DRG. When the femoral nerve is exposed, eGFP expression distinguishes the sensory branch (FS) from the motor branch (FM) in an intact mouse (Fig 3A and 3B). In addition, both the SMN located in the ventral horn of the spinal cord (arrowhead) and the central projections of DRG (arrows) can be visualized in the same section of the DRG (Fig 3C). However, since CSMN are also genetically labeled with eGFP, it is not possible to discern DRG axons and the branches of the corticospinal tract, innervating spinal targets. Cross-sections through the dorsal root reveal that all sensory axons labeled by neurofilament-H (NF-H) are also eGFP+ (Fig 3D), further demonstrating the presence of fluorescence in individual axon fibers.


Visualization of Sensory Neurons and Their Projections in an Upper Motor Neuron Reporter Line.

Genç B, Lagrimas AK, Kuru P, Hess R, Tu MW, Menichella DM, Miller RJ, Paller AS, Özdinler PH - PLoS ONE (2015)

Sensory axons are eGFP+.(A-B) eGFP expression in the axons of sensory branch of the femoral nerve (FS, arrows) makes it visible in vivo. FM: femoral nerve motor branch (arrowheads). (C) DRG axons innervating the dorsal and ventral horn of the spinal cord are labeled by eGFP (arrows). Spinal motor neurons (SMN) in the ventral horn are also GFP+ (arrowhead). (D) Cross-sections of the dorsal root show complete overlap between neurofilament-H (NF-H) labeled axons and eGFP expression in the UCHL1-eGFP mice, and there is no GFP in the WT mice. Scale bars A,B 1 mm; C 250 μm; D 50 μm; D inset 20 μm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4519325&req=5

pone.0132815.g003: Sensory axons are eGFP+.(A-B) eGFP expression in the axons of sensory branch of the femoral nerve (FS, arrows) makes it visible in vivo. FM: femoral nerve motor branch (arrowheads). (C) DRG axons innervating the dorsal and ventral horn of the spinal cord are labeled by eGFP (arrows). Spinal motor neurons (SMN) in the ventral horn are also GFP+ (arrowhead). (D) Cross-sections of the dorsal root show complete overlap between neurofilament-H (NF-H) labeled axons and eGFP expression in the UCHL1-eGFP mice, and there is no GFP in the WT mice. Scale bars A,B 1 mm; C 250 μm; D 50 μm; D inset 20 μm.
Mentions: We next investigated if eGFP was present in the axons, and whether de novo fluorescence would be strong enough to visualize axon tracts and individual fibers. We find that in the UCHL1-eGFP mice eGFP expression is present not only in the cell bodies (Fig 2A), but also in the peripheral (Fig 3A and 3B) and central (Fig 3C) projections of the DRG. When the femoral nerve is exposed, eGFP expression distinguishes the sensory branch (FS) from the motor branch (FM) in an intact mouse (Fig 3A and 3B). In addition, both the SMN located in the ventral horn of the spinal cord (arrowhead) and the central projections of DRG (arrows) can be visualized in the same section of the DRG (Fig 3C). However, since CSMN are also genetically labeled with eGFP, it is not possible to discern DRG axons and the branches of the corticospinal tract, innervating spinal targets. Cross-sections through the dorsal root reveal that all sensory axons labeled by neurofilament-H (NF-H) are also eGFP+ (Fig 3D), further demonstrating the presence of fluorescence in individual axon fibers.

Bottom Line: Our findings corroborate previous studies, and suggest that more than five months is required for significant skin denervation.Crossing UCHL1-eGFP with hSOD1G93A mice generated hSOD1G93A-UeGFP reporter line of amyotrophic lateral sclerosis, and revealed sensory nervous system defects, especially towards disease end-stage.Our studies not only emphasize the complexity of the disease in ALS, but also reveal that UCHL1-eGFP reporter line would be a valuable tool to visualize and study various aspects of sensory nervous system development and degeneration in the context of numerous diseases.

View Article: PubMed Central - PubMed

Affiliation: Davee Department of Neurology and Clinical Neurological Sciences, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States of America.

ABSTRACT
Visualization of peripheral nervous system axons and cell bodies is important to understand their development, target recognition, and integration into complex circuitries. Numerous studies have used protein gene product (PGP) 9.5 [a.k.a. ubiquitin carboxy-terminal hydrolase L1 (UCHL1)] expression as a marker to label sensory neurons and their axons. Enhanced green fluorescent protein (eGFP) expression, under the control of UCHL1 promoter, is stable and long lasting in the UCHL1-eGFP reporter line. In addition to the genetic labeling of corticospinal motor neurons in the motor cortex and degeneration-resistant spinal motor neurons in the spinal cord, here we report that neurons of the peripheral nervous system are also fluorescently labeled in the UCHL1-eGFP reporter line. eGFP expression is turned on at embryonic ages and lasts through adulthood, allowing detailed studies of cell bodies, axons and target innervation patterns of all sensory neurons in vivo. In addition, visualization of both the sensory and the motor neurons in the same animal offers many advantages. In this report, we used UCHL1-eGFP reporter line in two different disease paradigms: diabetes and motor neuron disease. eGFP expression in sensory axons helped determine changes in epidermal nerve fiber density in a high-fat diet induced diabetes model. Our findings corroborate previous studies, and suggest that more than five months is required for significant skin denervation. Crossing UCHL1-eGFP with hSOD1G93A mice generated hSOD1G93A-UeGFP reporter line of amyotrophic lateral sclerosis, and revealed sensory nervous system defects, especially towards disease end-stage. Our studies not only emphasize the complexity of the disease in ALS, but also reveal that UCHL1-eGFP reporter line would be a valuable tool to visualize and study various aspects of sensory nervous system development and degeneration in the context of numerous diseases.

No MeSH data available.


Related in: MedlinePlus