Emergence of Cortical Activity Patterns as Infants Develop Functional Motor Skills.

Despite the careful examination of the developmental changes in overt behavior and the underlying muscle activity and joint movement patterns, there is very little empirical evidence on how the brain and its link to behavior evolves during the first year of life. The dynamic systems approach and theory of neuronal group selection provides a framework that hypothesizes the development of the CNS early in life. However, the direct examination of the changes in brain activation that underlie the development of functional motor control in infants have yet to be determined or tested. The goal of my dissertation was to use functional near-infrared spectroscopy (fNIRS) to document the changes in brain activation patterns as infants acquired functional motor skills. My studies show that fNIRS is a viable and useful tool to examine brain activity in the context of infant movements. My findings demonstrate that as the behavioral and motor outcomes improve, the underlying neural activation patterns emerge. When functional motor skills are unstable and not fully functional, larger areas of the broad brain regions are recruited. As the skills become more reliable and functional, the brain activation patterns become refined and show an increase in strength of activity. The results from the studies in my dissertation take an important first step of describing the typical neural patterns that emerge with functional motor skills early in life. This work will help future studies build the body of empirical evidence that will improve our knowledge regarding the developing link between brain development and behavior. Finally, these studies provide foundational knowledge to better understand the atypical development of the CNS in those with disabilities.PhDKinesiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133452/1/ryonish_1.pd

fNIRS: An Emergent Method to Document Functional Cortical Activity during Infant Movements

The neural basis underlying the emergence of goal-directed actions in infants has been severely understudied, with minimal empirical evidence for hypotheses proposed. This was largely due to the technological constraints of traditional neuroimaging techniques. Recently, functional near-infrared spectroscopy (fNIRS) technology has emerged as a tool developmental scientists are finding useful to examine cortical activity, particularly in young children and infants due to its greater tolerance to movements than other neuroimaging techniques. fNIRS provides an opportunity to finally begin to examine the neural underpinnings as infants develop goal-directed actions.In this methodological paper, I will outline the utility, challenges, and outcomes of using fNIRS to measure the changes in cortical activity as infants reach for an object. I will describe the advantages and limitations of the technology, the setup I used to study primary motor cortex activity during infant reaching, and example steps in the analyses processes. I will present exemplar data to illustrate the feasibility of this technique to quantify changes in hemodynamic activity as infants move. The viability of this research method opens the door to expanding studies of the development of neural activity related to goal-directed actions in infants. I encourage others to share details of techniques used, as well, including analyticals, to help this neuroimaging technology grow as others, such as EEG and fMRI have

Prolonged gabapentin analgesia in an experimental mouse model of fibromyalgia

In a new mouse model for generalized pain syndrome, including fibromyalgia, which used intermittent cold stress (ICS), bilateral allodynia in the hindpaw was observed that lasted more than 12 days; thermal hyperalgesia lasted 15 days. During constant cold stress (CCS), mice showed only a transient allodynia. A female prevalence in ICS-induced allodynia was observed in gonadectomized but not in gonad intact mice. Systemic gabapentin showed complete anti-allodynic effects in the ICS model at the one-tenth dose for injury-induced neuropathic pain model, and central gabapentin showed long-lasting analgesia for 4 days in ICS, but not the injury model. These results suggest that the ICS model is useful for the study of generalized pain syndrome

Permanent relief from intermittent cold stress-induced fibromyalgia-like abnormal pain by repeated intrathecal administration of antidepressants

<p>Abstract</p> <p>Background</p> <p>Fibromyalgia (FM) is characterized by chronic widespread pain, which is often refractory to conventional painkillers. Numerous clinical studies have demonstrated that antidepressants are effective in treating FM pain. We previously established a mouse model of FM-like pain, induced by intermittent cold stress (ICS).</p> <p>Results</p> <p>In this study, we find that ICS exposure causes a transient increase in plasma corticosterone concentration, but not in anxiety or depression-like behaviors. A single intrathecal injection of an antidepressant, such as milnacipran, amitriptyline, mianserin or paroxetine, had an acute analgesic effect on ICS-induced thermal hyperalgesia at post-stress day 1 in a dose-dependent manner. In addition, repeated daily antidepressant treatments during post-stress days 1-5 gradually reversed the reduction in thermal pain threshold, and this recovery was maintained for at least 7 days after the final treatment. In addition, relief from mechanical allodynia, induced by ICS exposure, was also observed at day 9 after the cessation of antidepressant treatment. In contrast, the intravenous administration of these antidepressants at conventional doses failed to provide relief.</p> <p>Conclusions</p> <p>These results suggest that the repetitive intrathecal administration of antidepressants permanently cures ICS-induced FM pain in mice.</p