Laminin and BDNF synergistically induce local translation in axonal growth cones

Didn't your competent? doctor already have SPECIFIC PROTOCOLS ON BDNF AND AXONAL SPROUTING so you can recover properly?

axonal sprouting (52 posts to December 2011)

BDNF (198 posts to April 2011)

laminin (3 posts to October 2014)

Do you prefer your doctor, hospital and board of director's incompetence NOT KNOWING? OR NOT DOING? Your choice; let them be incompetent or demand action!

 Laminin and BDNF synergistically induce local translation in axonal growth cones

Nikita Kirkise1 and Kristy Welshhans1,2* 

1 Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA; 2 Carolina Autism and Neurodevelopment (CAN) Research Center, University of South Carolina, Columbia, SC 29208, USA 

 *Corresponding author: kwelshhans@sc.edu 

 Running title: Laminin regulates local translation

ABSTRACT The laminins are a family of extracellular matrix proteins that regulate numerous cellular processes, including adhesion, neurite outgrowth, and axon guidance. However, it remains unclear whether laminin regulates axon guidance through local translation. Here, we show that laminin is necessary for local translation in axonal growth cones. Local translation is significantly increased in growth cones of embryonic day 17 mouse cortical neurons, either cultured on or acutely stimulated with soluble laminin 111, in the presence of BDNF. When cultured on laminin isoforms 211 or 221 in the presence of BDNF, there was a remarkable decrease in local translation in growth cones. Using a puromycin-proximity ligation assay to examine newly synthesized b-actin specifically, we find a significant increase in growth cones of neurons cultured on laminin 111 in the presence of BDNF. However, soluble laminin 111 alone results in a significant reduction in nascent b-actin protein synthesis. These results indicate that laminin isoforms can act in multiple ways, including synergistically with guidance cues and independently, to modulate local mRNA translation, thereby differentially influencing axon growth and guidance during development. 

 SUMMARY STATEMENT Local translation in axons is critical for axon guidance. Laminin, a key component of the extracellular matrix, is necessary to induce local translation and thus mediate axon growth and guidance. 

 INTRODUCTION Accurate neural wiring is important for the formation of a healthy, functional brain. Changes in neural wiring or the failure to connect with synaptic targets can give rise to various neurological disorders (Van Battum et al., 2015). During development, this neural network is formed through axon guidance, wherein neuronal processes are directed to and establish connections with their synaptic targets (Bellon and Mann, 2018). Axon guidance is mediated by growth cones, which are highly dynamic and motile motor and sensory structures located at the tips of pathfinding axons. Growth cones respond to extracellular cues in their environment, which can be attractive or repulsive, as well as diffusible or contact-mediated (Gomez et al., 1996, Lowery and Vactor, 2009, Bixby and Harris, 1991, McFarlane and Holt, 1997). These cues are sensed by the receptors present on growth cone filopodia and lamellipodia, initiating signaling mechanisms that reorganize the cytoskeleton and allow the growth cone to advance towards, stall, or turn away from the cue (Myers et al., 2011). Contact-mediated cues, such as extracellular matrix (ECM) proteins, are critical in axon guidance. Laminin is a major component of the ECM and is widely expressed in both the peripheral and central nervous systems (Barros et al., 2011, McKerracher et al., 1996, Myers et al., 2011). Numerous studies have reported that laminin regulates axon guidance (Barros et al., 2011, Kuhn et al., 1995, McKerracher et al., 1996, Bonner and O'Connor, 2001, Paulus and Halloran, 2006). Moreover, netrin-1 is an attractive guidance cue for retinal neurons, but when a high concentration of laminin substrate is also present, netrin-1 becomes repellent to these neurons (Hopker et al., 1999). Similarly, retinal ganglion cells collapse in the presence of EphB and laminin, but when L1 is also present, then growth cone pausing occurs (Suh et al., 2004). Thus, laminin acts in concert with other guidance molecules to differentially remodel the cytoskeleton, but we currently have limited knowledge about how this signaling from multiple cues is integrated.

More at link. 

 

An historical review of selected functions of exogenous Nerve Growth Factor: selective binding, endocytosis, and axonal transpor

Is axonal transport similar to axonal sprouting? If so stroke survivors need it. What has your doctor done to accomplish axonal reconnections/remodeling? NOTHING? So you don't have a functioning stroke doctor? How the hell do you expect to 100% recover?

 An historical review of selected functions of exogenous Nerve Growth Factor: selective binding, endocytosis, and axonal transport

An historical review of selected functions of exogenous Nerve Growth Factor: selective binding,
endocytosis, and axonal transport
Kahl S.B.,* Burton L.E., ** Hill G.C.,*** and McKee, C.A.*
* PhD, Chief Scientific Officer, Manzanita Pharmaceuticals, Inc., Woodside, CA, US; ** PhD, consultant to Manzanita
Pharmaceuticals, Inc., LGB Consulting, San Mateo, CA, US; *** PhD, consultant to Manzanita Pharmaceuticals, Inc.;
Director, Radiopharm Development and Translation, SpectronRx, Indianapolis, IN, US; * MBA, Manzanita
Pharmaceuticals, Inc., Woodside, CA, US.
1 EXECUTIVE SUMMARY
Introduction. Nerve Growth Factor (NGF) was discovered by Rita Levi-Montalcini MD PhD in 1952 [1]
(Hamburger 1949 [2]; Cohen 1954 [3]; Levi-Montalcini 1976 [4]; Aloe 2004, 2012 [5, 6]). Nerve Growth Factor
has been considered as a therapeutic agent for multiple, mostly neurodegenerative conditions (Rocco 2018[7]). This review does not consider NGF as a potential, directly acting therapeutic agent. Rather, the scientific case is considered for NGF as a delivery facilitating moiety, to target the intraneuronal environment of peripheral nerves.
Historical review: methodology. This review considered the published literature as to exogenous
administration of NGF selective binding, internalization (endocytosis or phagocytosis), and axonal transport. This is not a systematic, but an historical narrative that identifies references from key papers as the main process. The review was conducted independently of the review paper, “Receptor binding, internalization, and retrograde transport of neurotrophic factors” (Neet and Campenot 2001 [8]).
One outcome of this review was noting that most of the basic research into the selective binding,
internalization, and axonal transport of NGF appears to have been completed by 2000. Since then, research has focused on various defects involving these processes in disease.
Product in development: the Nerve Growth Factor-fluorescent dye conjugate. This review examines the published literature of selected pharmacokinetics (PK) of Nerve Growth Factor (NGF), namely the emphasis on the mechanism and timing of binding to its receptors, whether the endocytosis of conjugates was possible, and the velocity of absorption, or retrograde axonal transport. Separately, we compared the published literature to results to date of our fluorescent dye-NGF conjugate, 800-rhNGF.
We are developing 800-rhNGF, a conjugate in which a known fluorescent dye in the 800 nanometer (nm) region is attached directly to amino acids located on the surface of recombinant human Nerve Growth Factor, NGF (800-rhNGF). Proprietary synthetic protocols leave both the dye free to fluoresce and NGF free to bind to its high and low affinity receptors, both of which are known. The first indication for 800-rhNGF is as a surgical guidance tool, a nerve imaging agent to be used in radical prostatectomies, in which localized, mostly early-stage prostate cancer is resected surgically.
After this review of the NGF literature, two separate comparisons evaluated whether the published NGF literature supported (i) the results of 800-rhNGF observed in non-GLP (GLP, Good Laboratory Practice) in rat studies to date (n=46) - yes; and (ii) the criteria for clinical workflow, as defined to us unanimously in detailed due diligence questions to urologic cancer surgeons – yes. Not reviewed are the characteristics of an 800 NIR dye which would also meet clinical criteria. Nonclinical results of 800-rhNGF will be published separately. This review focuses solely on what is known of the pharmacokinetics and science of NGF.
• Binding mechanism of NGF partly explains selectivity. It is definitive that (i) NGF binds with high affinity
for TrkA receptors; (ii) NGF also binds to the low affinity, “pan-neurotrophin” p75 receptor; (iii) binding to TrkA occurs within 3-6 min, to p75 within seconds (in PC12 cells, Godfrey and Shooter 1986; Senger and Campenot 1997 [9, 10]); (iv) TrkA and relatively more p75 receptors (percentage unknown) are expressed at the distal ends of nerves (Godfrey and Shooter 1986 [9]); and (v) TrkA is genetically encoded, and is highly homologous in all mammals, including humans ([11-13]).

For example, in an oncological resection of the prostate, the peri-prostastic space (“bed” of the initial surgical incision) enables access to TrkA and p75 receptors newly exposed after surgical incision. The other part of selectivity is that 800-rhNGF will ‘pool’ in the surgical space created by the incision. The relative benefits of localized vis-à-vis systemic administration are not reviewed here.
Table 1. Criteria for clinical utility for a nerve imaging agent to aid radical prostatectomies
Application At beginning of procedure, intra-operatively, interstitially (topically) to the peri-prostatic space (bed of initial surgical incision). No need to target any particular anatomical feature;
Wash Wash with saline three times (3X) after 15-30 min;
Durable Can be imaged at end of procedure, ~ 2h; Safe Degrades safely, so patient can be sutured up at the end of ~ 2h surgery; Clinical goal Does not interfere with primary goal, which is cancer control (does not tell surgeons what to do); and Benefits Intra-operative, intrastitial (topical, peri-prostatic) application should reduce systemic dose. Localized application of 800-rhNGF is likely to reduce patient in-surgery time, and reduce hospital cost if less time is spent in surgery and/or in hospital, if a day in hospital is spent if a nerve imaging agent is injected intravenously (IV). Not all nonclinical experiments distinguished carefully between whether the pro or mature form of NGF was used. It is critically important to understand this selection, since only the mature form binds to TrkA receptors (Luberg 2015; Fahnestock 2001; Ioannou and Fahnestock 2017; Shekari and Fahnestock 2019
[14-17]). For example, the 800-rhNGF nerve imaging agent under development uses only the mature form of NGF. As discussed further in Appendix D, “oncogene” describes the pro form of NGF, which is produced endogenously in adult mammals [18], but proNGF does not bind TrkA.
Endocytosis. The term endocytosis correctly describes endocytosis (“internalization”) of all proteins. What is reviewed here is the endocytosis of NGF-TrkA-(p75). It is known that the NGF-TrkA complex is moved intraneuronally, specifically on a ‘surface-bound’ path, on the outside of microtubules (Peters 1968, 1991 [19,20]; Rodriquez Echandia 1968 [21]; Burton P.R. 1984 [22]; Ure and Campenot 1997 [23]; Garvalov 2006 [24]).
Not reviewed are the specific mechanisms or the destination sites of transport of anterograde transport. What is not definitive is what primary and secondary signals are sent after NGF-receptor binding, and by what, to initiate endocytosis and then fast and slow retrograde axonal transport. Key findings from this review are:
(i) NGF is endocytosed with receptors TrkA and/or p75;
(ii) The NGF-receptor complex is probably transported in clathrin-coated vesicles (Howe 2001 [25]; Brown 2013 [26]);
(iii) NGF has been previously modified to involve even larger complexes than by comparison, the 800-rhNGF conjugate under development (mature form NGF kDA 26.3 is bound to fluorescent dye, MW 1015); and (iv) Once endocytosed, NGF-TrkA is loaded onto the retrograde axonal transport system with relatively high - 85% - efficiency (Ure and Campenot 1997 [23]).
Axonal transport. It is definitive that:
(i) Axonal transport includes NGF and other proteins;
(ii) There are fast (Brady 1984, 1993 [27, 28]; Brady 1985b [29]; Treanor 1995 [30]; Senger and Campenot 1997 [10]; Butowt and von Bartheld 2009 [31]) and slow components of axonal transport (Ure and Campenot 1997 [23]; Senger and Campenot 1997 [10]). The half-life of slow, retrogradely transported NGF in vitro is estimated at 6h (Ure and Campenot 1997 [23]);
(iii) Slow and fast axonal transport begins retrogradely (from the periphery to the neuronal cell body) (Hendry 1974a [32]; Brimijoin and Helland 1976 [33]; Allen 1982 [34]; Brady 1982 [35]; Stenoien and Brady 1999
[36]; Butowt and von Bartheld 2009 [31]);
(iv) In the neuronal cell body, the NGF-receptor complex is degraded into non-toxic components primarily by
proteolysis - by nucleases, proteases, esterases, glycosidases, lipases, phosphatases and sulfatases

(Avers 1982 [37]; Sheeler 1983 [38]; Parton and Dotti 1993 [39]; Hosang and Shooter 1986 [40];
Vissavajjhala 1992 [41]; Neet and Campenot 2001 [8]; Boutilier 2008 [42]; Frampton 2012 [43]); and
(v) Degraded, non-toxic NGF-receptor fragments are moved anterogradely (“orthograde” or anterograde
axonal transport), back to the periphery, channeling various products into various neuronal channels (Sec
3.3 Stenoien and Brady 1999 [36]; Butowt and von Bartheld 2009 [31]).
Future publications of nonclinical results of 800-rhNGF. Nonclinical results of 800-rhNGF will be published
in the future. Significantly, since the expression of Trk receptors is highly homologous in all mammals, the non-
GLP results to date in rat are clinically predictive. After NGF binds to TrkA and/or p75 receptors, absorption of
the NGF-receptor complex continues after wash, when the NGF-TrkA complex is loaded onto the retrograde
axonal transport system. ‘What the surgeon sees’ in the display of an imaging system is the 800 dye - not
indocyanine green (ICG) (Vahrmeijer 2013 [44]).
Ninety-nine per cent of the installed base of imaging systems are designed to detect a dye that fluoresces in
the 800 nm region: indocyanine green (ICG). The ability to visualize the 800 dye in 800-rhNGF has been
confirmed to date not only in all rat studies (total n=103), but also in two canine studies (n=2) that evaluated
two different marketed imaging systems. Both those imaging systems were designed to detect ICG, and
approved for marketing. This review does not discuss imaging systems. Future publication of nonclinical
results of 800-rhNGF will include:
(i) Dose range-finding studies (completed in rat, 1.0 mg/ml for Dye-Adduct-Ratio DAR2);
(ii) Signal-to-Background Ratio (SBR) calculations, from nerve-to-muscle (not nerve-in-adipose tissue)
measurements. As expected, SBR results reflect ‘steady state’ and the larger cargo size of the DAR2
variant: the SBR DAR2 was only ~ 25% higher than DAR1, even though number of molecules doubled
in the DAR2 variant from the DAR1 variant. In addition to the bioconjugation parameters, key
determinants were also the “brightness” of 800-rhNGF and sensitivity of the imaging systems;
(iii) Histology, using co-localization, TrkA was confirmed as a binding mechanism for 800-rhNGF. Neither
the binding of NGF to p75 nor the TrkA-p75 complex were assessed histologically; and
(iv) Canine studies, within the terms of the Non-Disclosure Agreements (NDAs) signed with three firms to
date. A fourth has expressed interest.
Contents of this Review
• In Sections 1 – 3 below, we review the selective binding, endocytosis, and axonal transport of NGF.
• Section 4 summarizes key findings from this review.

Directing Axonal Growth: A Review on the Fabrication of Fibrous Scaffolds That Promotes the Orientation of Axons

You'll need this axonal sprouting so ask your doctor what this will do for your recovery.

Directing Axonal Growth: A Review on the Fabrication ofFibrous Scaffolds That Promotes the Orientation of Axons

Devindraan Sirkkunan , Belinda Pingguan-Murphy and Farina Muhamad * Department of Biomedical Engineering, Faculty of Engineering, Universiti Malaya, Kuala Lumpur 50603, Malaysia; ezvn2066@gmail.com (D.S.); bpingguan@gmail.com (B.P.-M.) * Correspondence: farinamuhamad@um.edu.my Abstract: Tissues are commonly defined as groups of cells that have similar structure and uniformly perform a specialized function. A lesser-known fact is that the placement of these cells within these tissues plays an important role in executing its functions, especially for neuronal cells. Hence, the design of a functional neural scaffold has to mirror these cell organizations, which are brought about by the configuration of natural extracellular matrix (ECM) structural proteins. In this review, we will briefly discuss the various characteristics considered when making neural scaffolds. We will then focus on the cellular orientation and axonal alignment of neural cells within their ECM and elaborate on the mechanisms involved in this process. A better understanding of these mechanisms could shed more light onto the rationale of fabricating the scaffolds for this specific functionality. Finally, we will discuss the scaffolds used in neural tissue engineering (NTE) and the methods used to fabricate these well-defined constructs. Keywords: cellular orientation; fiber alignment; neural tissue engineering 1. Introduction Over the past 25 years, neurological disorders (ND) have been the leading case of disability and death worldwide [1]. According to the Global Burden of Disease Study (2015), ND is the leading cause of disability-adjusted life-years (DALY) in 2015 (229.1 to 274.7 million or 10.2% of global DALYs) and the second leading group of deaths (9.1 to 9.7 million or 16.8% of global deaths) [1]. ND such as Alzheimer’s accounts for the second highest number of deaths, whereas other motor neuron diseases still account for a fairly large number of deaths globally [1]. These neurological diseases involve the loss of neurons and synapses in various parts of the brain, spinal cord, and other parts of the all-encompassing peripheral nervous system. Despite the substantial decrease in mortality rates from stroke and communicable ND, its burden has increased in the past 25 years due to gradual increment of the aged population [1]. Hence, there is a need to prepare more efficient methods to provide adequate treatment for the ever-growing number of patients with ND. The current treatment strategy for ND that involves neuronal loss, such as trauma to the spinal cord, is definitive surgical decompression and/or stabilization [2]. Autologous peripheral nerve graft has also been used as a treatment for Parkinson’s disease [2]. However, this procedure of stabilization requires the transference of nerve from another part of the nervous system, as seen in the excision of sural nerve containing Schwann cells and its delivery into the Parkinson’s disease affected substantia nigra [2]. The increment in morbidity to patients using surgical procedures drives the research for other avenues in ND treatment technologies. As an alternative to nerve transplant, stem cell therapy provides a renewable source of auxiliary cells and tissues for a variety of ND [3]. Bone marrow cell transplantation has been used to treat spinal cord injury, and it is shown to be a viable option for patients with complete spinal cord injury [4]. However, the study shows only small improvements in the treatment of acute and sub-acute groups, but not in chronic groups [4]. This is may be due to the fact that the stem cells require a scaffold and vector to improve its functionality. Biomimetic nanofibrous scaffolds has been developed for NTE in order to provide sustained growth factor/drug release or to support cell growth in situ [5,6]. The ability to fine tune the biochemical properties of the nanofibers enables researchers to produce biomaterials that could mimic the ECM of native tissues [7,8]. This potential coupled with a high surface area to volume ratio and superior biocompatibility provides a technique to reduce cell death or neuropathy due to nonphysiological local stress [8,9]. Many methods have been employed to fabricate these scaffolds according to the desired functionality and specifications. Electrospinning is frequently used to fabricate scaffolds due to its ability to manipulate the developmental parameters such as porosity, surface area, fiber diameter, and its alignment therein [10]. It is considered as a standard technique for producing nanofibers in the field of NTE [11,12]. Another immerging technique to fabricate neural scaffolds is microfluidics [13,14]. This method requires no application of high temperature or voltage [15,16]. There are also other novel methods being developed to produce neural scaffolds, such as isoelectric focusing [17], wet spinning [18], and thermal drawing process [19]; with each technique improving the scaffolds attributes that could enhance and direct cellular growth. Development of these fabrication techniques adheres to certain protocols when it comes to scaffold production for tissue engineering purposes. Regardless of tissue types, a sustainable scaffold needs to be biocompatible and biodegradable [20]. Mechanical properties of the scaffolds are also an important consideration because the various culturable cells requires ECM of different stiffness for efficient growth [20]. Scaffold architecture such as the level of porosity and its interconnectivity has to be taken into account for 3D cell culture [20]. Finally, the methods used to fabricate these scaffolds has to be cost effective and up-scalable [20]. The fabrication of neural scaffolds applies these criterion guidelines in a more cell specific manner. Neural cells respond to a distinct topological cue, where the neuronal outgrowth needs to be guided and the connection between neurons has to be established for efficient growth [21]. Bearing this in mind, the scaffolds should mimic the native tissue ECM’s topological, mechanical, biochemical, and electrical cues to promote better contact guidance, adhesion, and proliferation of neuronal cells [21]. The radical scavenging ability should also be incorporated in to the scaffolds to minimize secondary progression of injury [21]. These scaffolds that are shaped and solidified in vitro requires surgical insertion into the affected site. A more immediate method of therapy would include on-site treatment to reduce scarring or accumulation of inhibitory proteins. Hence, in recent years, researchers look to injectable hydrogels as a viable option for minimally invasive treatment of various injuries [22–24]. These hydrogels could be administered immediately after injury, and since it does not require surgery to apply the scaffold, the morbidity from trauma would be greatly reduced [25]. However, injectable hydrogels do not have defined microarchitecture that is found in in-vitro patterned scaffolds [26–28]. This topology on scaffolds plays an important role in orientating cellular growth and building appropriate micro-structures that could provide sustained tissue development [26–28]. Current advancements in this new class of hydrogels employs nanoparticles and nanotubes to direct polymer fibers therein and in effect, direct the alignment of cells [26–28]. In this review, the examination of currently used hydrogels for NTE is presented. The recent methods of fabricating scaffolds with aligned microarchitecture is also outlined; where it ranges from the most commonly used techniques hitherto such as electrospinning to more novel ones that are currently being developed. Overall, the processes that leads to cellular alignment within these scaffolds or during the fabrication procedure are reviewed.

Molecular, cellular and functional events in axonal sprouting after stroke

 You need axonal sprouting so go ask your doctor for protocols that deliver it.

Molecular, cellular and functional events in axonal sprouting after stroke

Author links open overlay panelS. ThomasCarmichael

BalachandarKathirveluCatherine A.SchweppeEsther H.Nie

https://doi.org/10.1016/j.expneurol.2016.02.007Get rights and content

Highlights

•

Stroke induces the formation of new connections in brain and spinal cord.

•

These mediate some aspects of motor recovery.

•

A unique molecular program, a regenerative transcriptome, underlies post-stroke axonal sprouting.

•

Axonal sprouting occurs in three different patterns: reactive, reparative and unbounded.

•

Each pattern of post-stroke axonal sprouting has unique relationships to behavioral activity and molecular control points.

Abstract

Stroke is the leading cause of adult disability. Yet there is a limited degree of recovery in this disease. One of the mechanisms of recovery is the formation of new connections in the brain and spinal cord after stroke: post-stroke axonal sprouting. Studies indicate that post-stroke axonal sprouting occurs in mice, rats, primates and humans. Inducing post-stroke axonal sprouting in specific connections enhances recovery; blocking axonal sprouting impairs recovery. Behavioral activity patterns after stroke modify the axonal sprouting response. A unique regenerative molecular program mediates this aspect of tissue repair in the CNS. The types of connections that are formed after stroke indicate three patterns of axonal sprouting after stroke: reactive, reparative and unbounded axonal sprouting. These differ in mechanism, location, relationship to behavioral recovery and, importantly, in their prospect for therapeutic manipulation to enhance tissue repair.

Combinational Approach of Genetic SHP-1 Suppression and Voluntary Exercise Promotes Corticospinal Tract Sprouting and Motor Recovery Following Brain Injury

Now we need to know EXACTLY HOW MUCH EXERCISE TO DO. Ask your doctor and stroke hospital what they are doing to get human research done to create protocols for this.  No research then the whole leadership team including the board of directors needs to be fired.  You don't leave incompetent people in place when 100% recovery is on the line.

Combinational Approach of Genetic SHP-1 Suppression and Voluntary Exercise Promotes Corticospinal Tract Sprouting and Motor Recovery Following Brain Injury

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Takashi Tanaka, PhD, Tetsufumi Ito, PhD, Megumi Sumizono, PhD, ...

First Published May 22, 2020 Research Article Find in PubMed

https://doi.org/10.1177/1545968320921827

Article information

Abstract

Background.
Brain injury often causes severe motor dysfunction, leading to difficulties with living a self-reliant social life. Injured neural circuits must be reconstructed to restore functions, but the adult brain is limited in its ability to restore neuronal connections. The combination of molecular targeting, which enhances neural plasticity, and rehabilitative motor exercise is an important therapeutic approach to promote neuronal rewiring in the spared circuits and motor recovery.  
Objective.
We tested whether genetic reduction of Src homology 2-containing phosphatase-1 (SHP-1), an inhibitor of brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB) signaling, has synergistic effects with rehabilitative training to promote reorganization of motor circuits and functional recovery in a mouse model of brain injury.
Methods.
Rewiring of the corticospinal circuit was examined using neuronal tracers following unilateral cortical injury in control mice and in Shp-1 mutant mice subjected to voluntary exercise. Recovery of motor functions was assessed using motor behavior tests.  
Results.
We found that rehabilitative exercise decreased SHP-1 and increased BDNF and TrkB expression in the contralesional motor cortex after the injury. Genetic reduction of SHP-1 and voluntary exercise significantly increased sprouting of corticospinal tract axons and enhanced motor recovery in the impaired forelimb.  
Conclusions.
Our data demonstrate that combining voluntary exercise and SHP-1 suppression promotes motor recovery and neural circuit reorganization after brain injury.

Keywords brain injury, corticospinal tract, functional recovery, SHP-1, voluntary exercise

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Enzyme Treatment Restores Breathing, Limb Function in Rats with Injured Spinal Cords

We need axon growth especially in our white matter. WHOM is going to be following up on this to see if this could help post stroke? Do our doctors even know if proteoglycan is present in our brain post stroke?

Enzyme Treatment Restores Breathing, Limb Function in Rats with Injured Spinal Cords

Tue, 11/27/2018 - 3:46pm

by Kenny Walter - Digital Reporter -

@RandDMagazine

Using an enzyme approach, Case Western Reserve University researchers have found a way to reverse the long-term impact of spinal cord trauma on breathing and limb functions in rodent models.
The researchers found a new treatment regimen that reawakens certain special types of nerve cells that can regenerate extensions called axons within damaged spinal cord areas.
The treatment focuses on the body’s natural ability to slowly sprout new axon branches from a sub-population of nerve cells that remain intact below the injured site that is completely stifled by a family of potentially inhibitory molecules called proteoglycans.

Deeper Insights

Emerging HPC Trends

“The strategy was to use a simple, one-time injection of an enzyme, chondroitinase, that breaks down the inhibitory proteoglycan molecules,” senior author Jerry Silver, PhD, professor of neurosciences at Case Western Reserve University School of Medicine, said in a statement. “The enzyme was administered, not within the lesion itself, but lower down within the spinal cord where motor nerve cells reside that send axons out to the diaphragm and forearm.”
The researchers found that rats with spinal cords half severed at the second cervical vertebrae regained complete diaphragm and partial forelimb function on the severed side after treatment and the recuperative effects were fully maintained six months after treatment.
“For the first time we have permanently restored both breathing and some arm function in a form of high cervical, chronic spinal cord injury-induced paralysis,” Silver said. “The complete recovery, especially of breathing, occurs rapidly after a near lifetime of paralysis in a rodent model.”
The enzyme only marginally helped restore nerve growth with minimal functional recovery in animals treated immediately following the injury. However, when treated long after a spinal cord injury, the animals saw better therapeutic effects.
For example, one week after treatment, chronically injured rats saw new nerve extensions begin to restore diaphragm function that had been silent for several months. About 70 percent of the rats treated also started to use their forelimbs to move about and explore their environments, while only 30 percent of the control group restored those functions.
“Surprisingly, the technique worked far better at chronic stages than at acute stages after injury,” Silver said.
In fact, the longer the animals had been paralyzed, the greater the restorative effects. Even 18 months following injury, the rats who received the treatment recovered full diaphragm activity.
The researchers also found that exposing the rats to brief periods of low oxygen levels helped strengthen growing nerve extensions, but when the rats were treated with the enzyme combined with excessive amounts of respiratory therapy, they developed chaotic activity in their once paralyzed diaphragms.
The team now hopes to optimize both therapy options to maximize recovery, specifically in the forearm and paw.
“Our data illustrate the relative ease with which an essential motor system can regain functionality months to years after severe spinal cord injury,” Silver said. “The treatment regimen in our study is relevant to multiple types of chronic incomplete spinal traumas, and we are hopeful it may also help restore motor function following spinal cord injury in humans.”
According to research, there are between 250,000 and 500,000 new cases of chronic spinal cord injuries annually, with more than half of injuries impairing the person’s ability to breathe and the most severe injuries completely paralyzing the victim.
The study was published in Nature Communications.

Caltech researchers develop new method to see neural connections in living flies

Now if we could just accomplish this in humans. We could see which neurons are talking but no one is listening and map exactly the dead and damaged areas.  Using that knowledge to target axonal sprouting and dendrite branching to overcome those missing connections. Targeting interventions using nanotechnology to correct specific neurons could then be possible. I think grandiose ideas, but at least I think about solving stroke rather than sitting on my ass like the non-existent stroke leaders we have.
https://www.news-medical.net/news/20180112/Caltech-researchers-develop-new-method-to-see-neural-connections-in-living-flies.aspx

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January 12, 2018

The human brain is composed of billions of neurons wired together in intricate webs and communicating through electrical pulses and chemical signals. Although neuroscientists have made progress in understanding the brain's many functions--such as regulating sleep, storing memories, and making decisions--visualizing the entire "wiring diagram" of neural connections throughout a brain is not possible using currently available methods. But now, using Drosophila fruit flies, Caltech researchers have developed a method to easily see neural connections and the flow of communications in real time within living flies. The work is a step forward toward creating a map of the entire fly brain's many connections, which could help scientists understand the neural circuits within human brains as well.
A paper describing the work appears online in the December 12 issue of eLife. The research was done in the laboratory of Caltech research professor Carlos Lois.
"If an electrical engineer wants to understand how a computer works, the first thing that he or she would want to figure out is how the different components are wired to each other," says Lois. "Similarly, we must know how neurons are wired together in order to understand how brains work."
When two neurons connect, they link together with a structure called a synapse, a space through which one neuron can send and receive electrical and chemical signals to or from another neuron. Even if multiple neurons are very close together, they need synapses to truly communicate.
The Lois laboratory has developed a method for tracing the flow of information across synapses, called TRACT (Transneuronal Control of Transcription). Using genetically engineered Drosophila fruit flies, TRACT allows researchers to observe which neurons are "talking" and which neurons are "listening" by prompting the connected neurons to produce glowing proteins.
With TRACT, when a neuron "talks"--or transmits a chemical or electrical signal across a synapse--it will also produce and send along a fluorescent protein that lights up both the talking neuron and its synapses with a particular color. Any neurons "listening" to the signal receive this protein, which binds to a so-called receptor molecule--genetically built-in by the researchers--on the receiving neuron's surface. The binding of the signal protein activates the receptor and triggers the neuron it's attached to in order to produce its own, differently colored fluorescent protein. In this way, communication between neurons becomes visible. Using a type of microscope that can peer through a thin window installed on the fly's head, the researchers can observe the colorful glow of neural connections in real time as the fly grows, moves, and experiences changes in its environment.
Many neurological and psychiatric conditions, such as autism and schizophrenia, are thought to be caused by altered connections between neurons. Using TRACT, scientists can monitor the neuronal connections in the brains of hundreds of flies each day, allowing them to make comparisons at different stages of development, between the sexes, and in flies that have genetic mutations. Thus, TRACT could be used to determine how different diseases perturb the connections within brain circuits. Additionally, because neural synapses change over time, TRACT allows the monitoring of synapse formation and destruction from day to day. Being able to see how and when neurons form or break synapses will be critical to understanding how the circuits in the brain assemble as the animal grows, and how they fall apart with age or disease.

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TRACT can be localized to focus in on the wiring of any particular neural circuit of interest, such as those that control movement, hunger, or vision. Lois and his group tested their method by examining neurons within the well-understood olfactory circuit, the neurons responsible for the sense of smell. Their results confirmed existing data regarding this particular circuit's wiring diagram. In addition, they examined the circadian circuit, which is responsible for the waking and sleeping cycle, where they detected new possible synaptic connections.
TRACT, however, can do more than produce wiring diagrams. The transgenic flies can be genetically engineered so that the technique prompts receiving neurons to produce proteins that have a function, rather than colorful proteins that simply trace connections.
"We could use functional proteins to ask, 'What happens in the fly if I silence all the neurons that receive input from this one neuron?'" says Lois. "Or, conversely, 'What happens if I make the neurons that are connected to this neuron hyperactive?' Our technique not only allows us to create a wiring diagram of the brain, but also to genetically modify the function of neurons in a brain circuit."
Previous methods for examining neural connections were time consuming and labor intensive, involving thousands of thin slices of a brain reconstructed into a three-dimensional structure. A laboratory using these techniques could only yield a diagram for a single, small piece of fruit-fly brain per year. Additionally, these approaches could not be performed on living animals, making it impossible to see how neurons communicated in real time.
Because the TRACT method is completely genetically encoded, it is ideal for use in laboratory animals such as Drosophila and zebrafish; ultimately, Lois hopes to implement the technique in mice to enable the neural tracing of a mammalian brain. "TRACT is a new tool that will allow us to create wiring diagrams of brains and determine the function of connected neurons," he says. "This information will provide important clues towards understanding the complex workings of the human brain and its diseases."

Source:

http://www.caltech.edu/news/new-technology-will-create-brain-wiring-diagrams-80863