A combinatorial approach to modulate microenvironment toward regeneration and repair after spinal cord injury in rats.

Traumatic spinal cord injury (SCI) is a devastating condition of CNS which leads to loss of sensory as well as motor functions. Secondary damage after SCI initiates cascade of events that creates an inhibitory milieu for axonal growth and repair. Combinatorial therapies are the hope to attenuate secondary injury progression and make the microenvironment growth and repair friendly for the neurons. We fabricated gelatin- genipin hydrogel system which was impregnated with IONPs and injected at the lesion site in a clinically relevant contusion rat model of SCI. 24 h later, the rats were exposed to magnetic fields (17.96 µT, 50 Hz uniform EMF) for 2 h/day for 5 weeks. A significant (P < 0.001) improvement in Basso, Beattie and Bresnahan (BBB) locomotor score, amplitude and threshold of spinally mediated reflexes and motor and somatosensory evoked potentials (MEP & SSEP) was observed following IONPs implantation and EMF exposure. Moreover, retrograde tracing showed a higher level of neuronal connectivity and survival after the intervention. There was also a reduction in activated microglia and lesion volume which attenuate secondary damage as evident by reduction in the scaring following intervention for 5 weeks. Moreover, we observed increase in the neuronal growth cone marker, GAP-43, growth promoting neurotrophins (GDNF, BDNF & NT-3) and reduction in the inhibitory molecule (Nogo-A) after this combinatorial therapy. We obsrvered that a significant improvement in behavioral, electrophysiological and morphological parameters was due to an alteration in neurotrophin levels, reduction in activated microglia and increase in GAP-43 expression after the combinatorial therapy. We propose that implantation of IONPs embedded gelatin-genipin hydrogel system along with MF exposure modulated the microenvironment, making it conducive for neural repair and regeneration.

Evaluation of platelet-rich plasma on hair regrowth and lesional T-cell cytokine expression in alopecia areata: A randomized observer-blinded, placebo-controlled, split-head pilot study.

BACKGROUND: Platelet-rich plasma has shown some promise in the treatment of alopecia areata. OBJECTIVE: To evaluate the effect of platelet-rich plasma on hair regrowth and lesional T-cell cytokine expression in alopecia areata. METHODS: This was a randomized, placebo-controlled, split-head study involving 27 patients with alopecia areata (Severity of Alopecia Tool score ≥25%). Alopecia patches on either side of the scalp were randomized to receive 3 intradermal injections of platelet-rich plasma or normal saline at monthly intervals and evaluated 3 months after the last session. Lesional T-cell cytokine messenger RNA expression was compared pre- and posttreatment in the platelet-rich plasma-treated sites. RESULTS: The mean Severity of Alopecia Tool score did not change significantly compared with baseline with either platelet-rich plasma or placebo injections at any visit; however, the mean percentage reduction in the score in the platelet-rich plasma arm was more than in the placebo arm (9.05% ± 36.48% vs 4.99% ± 33.88%; P = .049) at final assessment. The mean interferon gamma (P = .001) and interleukin 17 cytokine (P = .009) messenger RNA expression decreased, whereas the mean interleukin 10 (P = .049) and FOXP3 (P = .011) messenger RNA expression increased significantly after platelet-rich plasma treatment. LIMITATIONS: Small sample size and a relatively short follow-up. CONCLUSION: Platelet-rich plasma was found to have limited efficacy in alopecia areata. However, it may play a role in restoring immune balance in the alopecic patches.

Neuroregenerative Effects of Electromagnetic Field and Magnetic Nanoparticles on Spinal Cord Injury in Rats.

The present study aimed to evaluate the effect of iron oxide nanoparticles (IONPs) along with electromagnetic fields (MF) exposure on spontaneous and induced axonal sprouting after spinal cord injury (SCI). Adult male Wistar rats were subjected to spinal cord transection at the T13 segment. The IONP (25 µg/mL) embedded in 3% agarose gel was implanted at the injury site and subsequently exposed to MF (50 Hz, 17.96 µT, 2 hours/day for 5 weeks). Histological analysis of spinal cord tissue showed a significant increase in the expression of the growth-associated protein GAP-43 and it was found to be co-localized with neuronal nuclei marker and neurofilaments. The results show sprouting from mature neurons and axons, significantly less demyelination and more myelinated fibers were evident at the lesion site. However, no motor or somatosensory evoked potential response was observed, suggesting lack of long-distance functional connectivity. These findings highlight the therapeutic potential of IONPs along with MF exposure in promoting neuroregeneration after SCI.

Extremely low-frequency electromagnetic fields: A possible non-invasive therapeutic tool for spinal cord injury rehabilitation.

Traumatic insults to the spinal cord induce both immediate mechanical damage and subsequent tissue degeneration. The latter involves a range of events namely cellular disturbance, homeostatic imbalance, ionic and neurotransmitters derangement that ultimately result in loss of sensorimotor functions. The targets for improving function after spinal cord injury (SCI) are mainly directed toward limiting these secondary injury events. Extremely low-frequency electromagnetic field (ELF-EMF) is a possible non-invasive therapeutic intervention for SCI rehabilitation which has the potential to constrain the secondary injury-induced events. In the present review, we discuss the effects of ELF-EMF on experimental and clinical SCI as well as on biological system.

Neuroprotective Potential of Superparamagnetic Iron Oxide Nanoparticles Along with Exposure to Electromagnetic Field in 6-OHDA Rat Model of Parkinson's Disease.

Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting mainly the dopaminergic neurons of the substantia nigra leading to various motor and non-motor deficits. We explored the neuroprotective potential of superparamagnetic iron oxide nanoparticles (IONPs) along with exposure to EMF in 6-OHDA rat model of PD. IONPs were implanted at the site of lesion and 24 h thereafter the rats were exposed to magnetic fields 2 h/day for one week. Bilateral lesions of the striatum were made with 6-OHDA. The rats in all the intervention groups improved progressively over the days and by post-surgery day 4 they were active and bright. We observed a significant beneficial effect of the IONPs implantation and MF exposure on feeding behavior, gait and postural stability. There was a significant enhancement of mitochondrial function and attenuation of lesion volume in all the intervention groups as compared to PD. The results demonstrate neuroprotective effect of iron oxide nanoparticle implantation and magnetic field exposure in an in vivo 6-OHDA rat model of PD.

BDNF mediated activity dependent maturation of visual Wulst following prenatal repetitive auditory stimulation at a critical developmental period in domestic chicks (Gallus domesticus).

The developing visual circuitry attains its mature adult pattern through the process of activity-dependent refinement in which photic stimulation plays the major role. However, auditory stimulation can also facilitate the developing visual Wulst synaptic plasticity and postnatal perceptual behavior, though the underlying mechanism is unclear. We exposed the fertilized eggs of white Leghorn chickens during incubation to either species-specific calls or no sound for varying time periods depending on the functional development of the auditory and/or visual systems. The visual evoked potential (VEP) from the Wulst was recorded at embryonic days (E) 19, 20 and posthatch days (PH) 1-3, to assess functional maturation. A significant attenuation in latencies and higher amplitudes at PH1-3 in the stimulated groups that received exposure during visual system maturation, suggest beneficial effect of auditory inputs only during critical periods. Concomitant with this, there was a significant increase in the expression of BDNF and levels of neurotransmitters GABA, glutamate, norepinephrine and serotonin from E18 only in both hemispheres of the visual Wulst. A significant inter-hemispheric difference in expression was also found in all groups. These results suggest the role of BDNF in activity driven structural and functional maturation of the visual system following prenatal repetitive auditory stimulation.

Prenatal music stimulation facilitates the postnatal functional development of the auditory as well as visual system in chicks (Gallus domesticus).

Rhythmic sound or music is known to improve cognition in animals and humans. We wanted to evaluate the effects of prenatal repetitive music stimulation on the remodelling of the auditory cortex and visual Wulst in chicks. Fertilized eggs (0 day) of white leghorn chicken (Gallus domesticus) during incubation were exposed either to music or no sound from embryonic day 10 until hatching. Auditory and visual perceptual learning and synaptic plasticity, as evident by synaptophysin and PSD-95 expression, were done at posthatch days (PH) 1, 2 and 3. The number of responders was significantly higher in the music stimulated group as compared to controls at PH1 in both auditory and visual preference tests. The stimulated chicks took significantly lesser time to enter and spent more time in the maternal area in both preference tests. A significantly higher expression of synaptophysin and PSD-95 was observed in the stimulated group in comparison to control at PH1-3 both in the auditory cortex and visual Wulst. A significant inter-hemispheric and gender-based difference in expression was also found in all groups. These results suggest facilitation of postnatal perceptual behaviour and synaptic plasticity in both auditory and visual systems following prenatal stimulation with complex rhythmic music.

Prenatal loud music and noise: differential impact on physiological arousal, hippocampal synaptogenesis and spatial behavior in one day-old chicks.

Prenatal auditory stimulation in chicks with species-specific sound and music at 65 dB facilitates spatial orientation and learning and is associated with significant morphological and biochemical changes in the hippocampus and brainstem auditory nuclei. Increased noradrenaline level due to physiological arousal is suggested as a possible mediator for the observed beneficial effects following patterned and rhythmic sound exposure. However, studies regarding the effects of prenatal high decibel sound (110 dB; music and noise) exposure on the plasma noradrenaline level, synaptic protein expression in the hippocampus and spatial behavior of neonatal chicks remained unexplored. Here, we report that high decibel music stimulation moderately increases plasma noradrenaline level and positively modulates spatial orientation, learning and memory of one day-old chicks. In contrast, noise at the same sound pressure level results in excessive increase of plasma noradrenaline level and impairs the spatial behavior. Further, to assess the changes at the molecular level, we have quantified the expression of functional synapse markers: synaptophysin and PSD-95 in the hippocampus. Compared to the controls, both proteins show significantly increased expressions in the music stimulated group but decrease in expressions in the noise group. We propose that the differential increase of plasma noradrenaline level and altered expression of synaptic proteins in the hippocampus are responsible for the observed behavioral consequences following prenatal 110 dB music and noise stimulation.

Iron oxide nanoparticles and magnetic field exposure promote functional recovery by attenuating free radical-induced damage in rats with spinal cord transection.

BACKGROUND: Iron oxide nanoparticles (IONPs) can attenuate oxidative stress in a neutral pH environment in vitro. In combination with an external electromagnetic field, they can also facilitate axon regeneration. The present study demonstrates the in vivo potential of IONPs to recover functional deficits in rats with complete spinal cord injury. METHODS: The spinal cord was completely transected at the T11 vertebra in male albino Wistar rats. Iron oxide nanoparticle solution (25 µg/mL) embedded in 3% agarose gel was implanted at the site of transection, which was subsequently exposed to an electromagnetic field (50 Hz, 17.96 µT for two hours daily for five weeks). RESULTS: Locomotor and sensorimotor assessment as well as histological analysis demonstrated significant functional recovery and a reduction in lesion volume in rats with IONP implantation and exposure to an electromagnetic field. No collagenous scar was observed and IONPs were localized intracellularly in the immediate vicinity of the lesion. Further, in vitro experiments to explore the cytotoxic effects of IONPs showed no effect on cell survival. However, a significant decrease in H2O2-mediated oxidative stress was evident in the medium containing IONPs, indicating their free radical scavenging properties. CONCLUSION: These novel findings indicate a therapeutic role for IONPs in spinal cord injury and other neurodegenerative disorders mediated by reactive oxygen species.

Exposure to extremely low-frequency magnetic field restores spinal cord injury-induced tonic pain and its related neurotransmitter concentration in the brain.

Spinal cord injury (SCI) is unequivocally reported to produce hyperalgesia to phasic stimuli, while both hyper- and hypoalgesia to tonic stimuli. The former is spinally mediated and the latter centrally. Besides, its management is unsatisfactory. We report the effect of magnetic field (MF; 17.96 µT, 50 Hz) on tonic pain behavior and related neurotransmitters in the brain of complete thoracic (T13) SCI rats at week 8. Adult male Wistar rats were divided into Sham, SCI and SCI+MF groups. Formalin-pain behavior was compared utilizing 5 min block pain rating (PR), 60 min session-PR, time spent in various categories of increasing pain (T0-T3) and flinch incidences. Serotonin (5-HT), dopamine (DA), norepinepherine (NE), gamma-aminobutyric acid (GABA), glutamate and glycine were estimated in brain tissue by liquid chromatography-mass spectrometry. Session-PR, block-PR and number of flinches were significantly lower, while time spent in categories 0-1 was higher in the SCI versus Sham group. These parameters were comparable in the SCI+MF versus Sham group. 5-HT concentration in cortex, remaining forebrain areas and brain stem (BS), was lower while GABA and NE were higher in BS of SCI, which were comparable with Sham in the SCI+MF group. The concentration of DA, glutamate and glycine was comparable amongst the groups. The data indicate significant hypoalgesia in formalin pain while increased in GABA, NE and decreased in 5-HT post-SCI, which were restored in the SCI+MF group. We suggest beneficial effect of chronic (2 h/day × 8 weeks) exposure to MF (50 Hz, 17.96 µT) on tonic pain that is mediated by 5-HT, GABA and NE in complete SCI rats.

Exposure to ELF- magnetic field promotes restoration of sensori-motor functions in adult rats with hemisection of thoracic spinal cord.

Clinically effective modalities of treatment for spinal cord injury (SCI) still remain unsatisfactory and are largely invasive in nature. There are reports of accelerated regeneration in injured peripheral nerves by extremely low-frequency pulsed electromagnetic field (ELF-EMF) in the rat. In the present study, the effect of (50 Hz), low-intensity (17.96 µT) magnetic field (MF) exposure of rats after-hemisection of T13 spinal cord (hSCI) was investigated on sensori-motor and locomotor functions. Rats were divided into hSCI (sham-exposed) and hSCI+MF (MF: 2 h/d X 6 weeks) groups. Besides their general conditions, locomotor function by Basso, Beattie, and Brenahan (BBB) score; motor responses to noxious stimuli by threshold of tail flick (TTF), simple vocalization (TSV), tail flick latency (TFL), and neuronal excitability by H-reflex were noted. It is found that, in the hSCI+MF group, a statistically significant improvement over the hSCI control group was noted in BBB score from post-SCI wk2 and TFL and TTF by post-hSCI wk1 and wk3, respectively. Correspondingly, TSV gradually restored by post-hSCI wk5.The threshold of H-reflex was reduced on ipsilateral side vs. contralateral side in hSCI and hSCI+MF group. A complete bladder control was dramatically restored on post-hSCI day4 (vs. day7 of hSCI group) and the survival rate was 100% in the hSCI+MF group (vs. 90% of hSCI group). The results of our study suggest that extremely low-frequency (50 Hz), low-intensity (17.96 µT) MF exposure for 2 h/d x 6wks promotes recovery of sensori-motor behavior including locomotion and bladder control both in terms of temporal pattern and magnitude in hemisection injury of (T13) spinal cord rats.

Effect of magnetic field on food and water intake and body weight of spinal cord injured rats.

Chronic (2 h/d x 8 weeks) exposure to magnetic field (MF; 50 Hz, 17.9 microT) in complete spinal cord (T13) transected rats restored food intake (FI), water intake (WI) and body weight (BW) which were decreased in the spinal cord injured rats. The results suggest a significant beneficial effect of chronic exposure to magnetic field of paraplegic rats.

Effect of prenatal species-specific and music stimulation on the postnatal auditory preference of domestic chick.

Perinatal sensory experience plays an important role in the development of perceptual preferences. In the present study prenatal enrichment with sound stimulus was given to see its effect on the development of postnatal auditory preference. Auditory stimulation with either species-specific (chicken maternal and hatching calls) or music (slow and fast sitar music) sounds was provided to two separate sets of fertilized eggs from the day 10 of incubation. The postnatal auditory preference of the chicks to either species-specific or music sounds was then tested at different time periods after hatching. All the chicks, irrespective of the type of prenatal exposure, showed preference for species-specific maternal calls. Notably, the music stimulated chicks did not show preference for either slow or fast music. In both the experimental groups, the number of chicks responding to the species-specific maternal calls was significantly (P<0.001) more at 24 h and 48 h post hatch, when compared with the unstimulated control group. Comparison of the species-specific stimulated group with the music stimulated group, for auditory preference to the maternal calls, did not show any significant difference. Further, in the species-specific sound stimulated groups, there was a significant (P<0.001) increase in the number of chicks responding to maternal calls at 60 h of age with repeated testing. However, there was no effect of peer imprinting on the auditory preference of the chicks, in both the experimental groups. The results indicate that prenatal auditory experience with either species-specific or non-specific music enhances the postnatal auditory preference of chicks for the species-specific sounds.