Pupose: This study was done to determine whether diffusion MRI (dMRI) can detect neuroprotective and regenerative effects of fibroblasts secreting brain derived neurotrophic factor (Fb-BDNF) in the white matter (WM) of the spinal cord following injury. Materials and Methods: Unmodified fibroblasts (Fb-UM) (N=2) or Fb-BDNF (N=2) were placed in a hemisection cavity. Sacrifice was at 1 or 8 weeks. Following perfusion fixation, dMRI was performed. Apparent diffusion coefficients (ADC's) parallel and perpendicular to the long axis of the cord were obtained in the rubrospinal tract (RST) where prior research has shown that Fb-BDNF transplants provide neuroprotection and promote axonal regeneration. Results: At 1 week, Fb-UM and Fb-BDNF ADC's in WM were similar, however abnormal as compared to control. At 8 weeks, ADC's rostral to the transplant were near normal in Fb-BDNF, while remaining abnormal in Fb-UM. The anisotropy index, abnormal in Fb-UM and Fb-BDNF at 1 week, was near normal rostral in Fb-BDNF by 8 wee...

Rats explore their environment with their whiskers whisking at rates up to 25 whisks/s. ~7 whisks/s dominate. Additional, less prominent, spectral peaks can be observed at lower and higher rates. We examined the effect of frequency of whisker deflection on the blood oxygenation level-dependent (BOLD) signal in rat somatic sensory cortex with functional magnetic resonance imaging at 4.7 T using a FLASH sequence in a block design [Sachdev et al., NeuroImage 19:742]. Five adult Long-Evans rats were trained to tolerate immobilization with restraint. Stress effects were suppressed with diazepam sedation (Valium, 12 mg/kg b.w., i.p.). The rats were imaged twice. Two 4-minute epochs of rest were alternated with two equivalent epochs of whisker stimulation. Nine caudal mystacial whiskers on the right side were deflected simultaneously with 1, 3 or 9 air puffs/s. Whisker stimulation at the three frequencies increased the BOLD signal in primary and secondary somatic sensory cortex on both sides statistically signifi...

Numerous functional magnetic resonance imaging (fMRI) episodic memory studies demonstrate that contrasting correctly recognized studied items (HIT) against correctly rejected novel items (CR), known as "Retrieval success effect", yields activation in di...

Diffusion weighted Magnetic Resonance Imaging (dMRI) and subsequent tractography-based modeling allows characterizing and quantifying connectivity and tissue properties of white-matter in living brains. By integrating this fiber-tracking information wit...

Network neuroscience leverages diffusion magnetic resonance imaging and tractography to quantify structural connectivity of the human brain. However, scientists and practitioners lack both a standardized tractography pipeline and a clear understanding o...

Understanding the relationship between neural activity and cortical hemodynamics, or neurovascular coupling is the foundation to interpret neuroimaging signals such as functional magnetic resonance imaging (fMRI) which measure local changes in hemodynam...

Vergence eye movements allow animals with frontally-positioned eyes to foveate objects of interest located at different depths in the visual field. Over the past two decades, there has been steady progress in elucidating the components of the neural net...

Task functional Magnetic Resonance Imaging (fMRI) enables the identification of specific brain areas associated with particular tasks. While multiple brain areas are involved for performing various tasks, existing methodological approaches with fMRI foc...

Introduction: Anterior interosseous nerve (AIN) syndrome is a rare disorder with complex clinical presentations. Anatomical variation of the proximal median nerve has been reported and should be confirmed before identifying the lesion of AIN. Methods: W...

The development of the corpus callosum (CC) in rhesus monkeys was investigated using non-invasive magnetic resonance imaging (MRI) techniques. Eleven infant and juvenile monkeys (6 males, 5 females) were scanned in the coronal and sagittal planes using a T-1 weighted imaging sequence from 5 to 115 weeks of age. Also, five adult male monkeys (3-7 years) were scanned using identical procedures. The midsagittal image was used to identify the CC. The CC was segmented into seven subregions (rostrum, genu, rostral body, anterior midbody, posterior midbody, isthmus, and splenium) as described by Witelson, et al. (Brain, 1989, 112:799). Using the Image J software, the surface area of each segment was measured and summed to provide total midsagittal CC surface. Total brain volume (TBV) was also calculated by measuring the surface area of coronal sections at 5mm intervals through the entire brain. CC data, either uncorrected or corrected for TBV, were analyzed for linear maturational trends for both males and female...