Functional roles of oral reflexes in chewing and biting: phase-, task- and site-dependent reflex sensitivity

Because loading during chewing is not totally predictable and jaw-closing muscles are strong and act over short distances, feedback from oral receptors is important in the control of mastication. Information on such feedback can be obtained by studying reflexes in jaw muscle EMGs. This review will deal with the contribution of reflex mechanisms to modifying motor neuron activity during chewing, and the dependency of reflex sensitivity on motor task, phase of movement, and site of stimulation.     

Treatments of unilateral neglect: a review

OBJECTIVES: To review the existing literature on treatments of unilateral neglect, to synthesize findings, and to offer recommendations for future studies. DATA SOURCES: Computerized databases including MEDLINE and PsychINFO. STUDY SELECTION: All studies investigating treatment(s) of unilateral neglect. DATA EXTRACTION: Authors reviewed design and other methodologic issues. DATA SYNTHESIS: Unilateral neglect is a common consequence of right-hemisphere stroke. It is well recognized that the disorder is heterogeneous and has numerous subtypes. There have been numerous studies showing that arousal, hemispheric activation, and spatial attention treatments may all improve neglect, at least transiently. Despite these promising outcomes, little consensus exists as to whether 1 treatment is more efficacious than others, in part because cross-study differences in methodology render meta-analyses difficult, and in part because many studies fail to document duration of treatment effects or generalization to daily activities. One possibility is that these varied and diverse treatments may all be effective, reflecting redundancy in neural circuits devoted to attention and action in space, and consequent flexibility of the spatial processing system. It remains possible, however, that different subtypes of neglect may respond differentially to treatment of various sorts. Most existing studies of neglect have relied on very small populations of neglect patients, whose neglect is characterized only generally. CONCLUSION: Methodologic shortcomings hinder assessment of the efficacy of various types of neglect treatment. In the future, these shortcomings could be addressed with larger studies of well-characterized patients that evaluate duration of treatment effects and include functional measures. In addition, the role of overarching variables, such as reduced arousal, requires consideration. The ultimate goal of these studies might be the development of triaging strategies wherein neglect patients are assigned to treatments of most likely benefit on the basis of neuroanatomic and behavioral profiles.     

Suicidality in Non-Treatment Seeking Young Adults with Subsyndromal Gambling Disorder

Gambling Disorder is associated with elevated rates of suicidal thoughts and acts. However, virtually nothing is known about suicidality in people with subsyndromal forms of gambling disorder. A total of 174 non-treatment seeking subjects were recruited for a study of impulsivity and met criteria for a subsyndromal form of DSM-5 gambling disorder (31.0 % females; mean age = 21.7 ± 3.61 years). Subjects were categorized as being ‘at risk of suicide’ or ‘no suicide risk’ based on the Mini-International Neuropsychiatric Interview (MINI). Those with and without suicidality were compared on clinical and cognitive measures. 32 (18.4 %) met MINI criteria for suicidality. Suicidality was significantly associated with mood and anxiety disorders, greater rates of nicotine consumption, and relative impairments in decision-making and cognitive flexibility. These findings suggest that decision-making impairments may be implicated in the development of both gambling problems and suicidality. Future work should address causality, neural correlates, and tailored suicide prevention strategies for people with, or at risk for, disordered forms of gambling.     

Stat3 mediates LIF‐induced protection of astrocytes against toxic ROS by upregulating the UPC2 mRNA pool

Reactive oxygen species (ROS) have been implicated in various types of CNS damage, including stroke. We used a cultured astrocyte model to explore mechanisms of survival of CNS cells following ROS damage. We found that pretreatment with leukemia inhibitory factor (LIF) preserves astrocytes exposed to toxic levels of t‐BHP by inhibiting an increase in intracellular ROS following t‐BHP treatment. Astrocytes lacking functional Stat3 did not benefit from the pro‐survival or antioxidant effects of LIF. Inhibition of mitochondrial uncoupling protein 2 (UCP2) using a chemical inhibitor or siRNA abrogates the prosurvival effects of LIF, indicating a critical role for UCP2 in modulation of mitochondrial ROS production in survival following ROS exposure. LIF treatment of astrocytes results in increased UCP2 mRNA that is accompanied by an increase in Stat3 binding to the UCP2 promoter region. Although treatment with LIF alone did not increase UCP2 protein, a combination of LIF treatment and ROS stress led to increased UCP2 protein levels. We conclude that LIF protects astrocytes from ROS‐induced death by increasing UCP2 mRNA, allowing cells to respond to ROS stress by rapidly producing UCP2 protein that ultimately decreases endogenous mitochondrial ROS production. GLIA 2014;62:159–170