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Hamblin, M. R.

Publications and source records attributed to Hamblin, M. R..

2 recordsLinked to original sources

4-Methyllumbiferone (4-MU) exerts a neuroprotective effect against cerebral ischemia/reperfusion injury by ameliorating learning and memory impairments

BackgroundStroke is the sixth leading cause of death and lifelong disability for millions of people in the United States. Cerebral ischemia leads to oxidative stress, excitotoxicity, inflammation, apoptosis; additionally, impairments in memory and learning occur in the majority of subjects with ischemic stroke. The lack of definitive treatment has sparked extensive research into novel therapeutic strategies, including the use of 4-methylumbelliferone (4-MU), a coumarin derivative with potential neuroprotective properties. The present study examines the impact of 4-MU on reducing cerebral ischemia-reperfusion (I/R) injury and learning and memory impairments in male Wistar rats. MethodThe animals were exposed to middle cerebral artery occlusion (MCAO) and were treated with one dose of 4-MU (at a dosage of 25 mg/kg) dissolved in DMSO 0.9%. Automated shuttle box and Morris water maze (MWM) test were employed to evaluate learning and memory impairments. Western blot assay, TTC staining and Nissl staining were used to measure protein expression, infarct volume, and cell death, respectively. ResultsResults showed that treatment with 4-MU reduced infarct volume and improved learning and memory impairments by down-regulating HAS1 and HAS2. 4-MU has been shown to modulate the release of pro-inflammatory cytokines including TNF- and IL-1{beta}, as well as anti-inflammatory markers like IL-10 and also reduced oxidative stress markers in the brain. ConclusionGenerally, the neuroprotective effects of 4-MU against cerebral I/R injury can be attributed to the down-regulation of HAS1 and HAS2.

neuroscience↗

Transcranial Near-Infrared Light: Dose-Dependent Effects on EEG Oscillations but not Cerebral Blood Flow

ObjectiveOur objective was to assess whether transcranial photobiomodulation (tPBM) with near-infrared light (NIR) shows modulatory effects on cerebral electrical activity through electroencephalogram (EEG) and cerebral blood flow (CBF). BackgroundtPBM has emerged as a novel intervention for several neuropsychiatric conditions due to its neuroprotective and neuroenhancement effects. MethodsWe conducted a single-blind, sham-controlled pilot study to test the effect of continuous (c-tPBM), pulse (p-tPBM) and sham (s-tPBM) transcranial photobiomodulation on EEG oscillations and CBT using diffuse correlation spectroscopy (DCS) in a sample of ten healthy subjects [6 F/ 4 M; mean age 28.6 {+/-} 12.9 (SD) years]. c-tPBM NIR (830 nm; 54.8 mW/cm{superscript 2}; 65.8 J/cm{superscript 2}; 2.3 kJ) and p-tPBM (830 nm; 10Hz; 54.8 mW/cm{superscript 2}; 33%; 21.7 J/cm{superscript 2}; 0.8 kJ) were delivered concurrently to the frontal areas (F4, Fp2, Fp1, F3 - total surface 35.8 cm{superscript 2}) by four LED clusters (TPBM-1000 Litecure). EEG and DCS recordings were performed weekly before, during, and after each tPBM session (in sequence: c-tPBM, s-tPBM and p-tPBM). ResultsOnly c-tPBM significantly boosted gamma (t = 3.02, df = 7, p < .02) and beta (t = 2.91, df = 7, p < .03) EEG spectral powers in eyes-open recordings and gamma power (t = 3.61, df = 6, p < .015) in eyes-closed recordings, with the largest effects in the posterior regions. There was no significant effect of NIR-tPBM on CBF compared to sham. ConclusionsOur data suggest a dose-dependent effect of tPBM with NIR (c-tPBM) on cerebral gamma and beta neuronal activity. Altogether, our findings support the neuromodulatory effect of transcranial NIR.

neuroscience↗