EphrinB2 knockdown in cervical spinal cord preserves diaphragm innervation in a mutant SOD1 mouse model of ALS

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by motor neuron loss. Importantly, non-neuronal cell types such as astrocytes also play significant roles in disease pathogenesis. However, mechanisms of astrocyte contribution to ALS remain incompletely understood. Astrocyte involvement suggests that transcellular signaling may play a role in disease. We examined contribution of transmembrane signaling molecule ephrinB2 to ALS pathogenesis, in particular its role in driving motor neuron damage by spinal cord astrocytes. In symptomatic SOD1G93A mice (a well-established ALS model), ephrinB2 expression was dramatically increased in ventral horn astrocytes. Reducing ephrinB2 in the cervical spinal cord ventral horn via viral-mediated shRNA delivery reduced motor neuron loss and preserved respiratory function by maintaining phrenic motor neuron innervation of diaphragm. EphrinB2 expression was also elevated in human ALS spinal cord. These findings implicate ephrinB2 upregulation as both a transcellular signaling mechanism in mutant SOD1-associated ALS and a promising therapeutic target.

Surgical evacuation for chronic subdural hematoma: Predictors of reoperation and functional outcomes

Background

Although chronic subdural hematoma (CSDH) incidence has increased, there is limited evidence to guide patient management after surgical evacuation.

Objective

To identify predictors of reoperation and functional outcome after CSDH surgical evacuation.

Methods

We identified all patients with CSDH between 2010 and 2018. Clinical and radiographic variables were collected from the medical records. Outcomes included reoperation within 90 days and poor (3-6) modified Rankin Scale score at 3 months.

Results

We identified 461 surgically treated CSDH cases (396 patients). The mean age was 70.1 years, 29.7 % were females, 298 (64.6 %) underwent burr hole evacuation, 152 (33.0 %) craniotomy, and 11 (2.4 %) craniectomy. Reoperation rate within 90 days was 12.6 %, whereas 24.2 % of cases had a poor functional status at 3 months. Only female sex was associated with reoperation within 90 days (OR = 2.09, 95 % CI: 1.17-3.75, P = 0.013). AMS on admission (OR = 5.19, 95 % CI: 2.15-12.52, P < 0.001) and female sex (OR = 3.90, 95 % CI: 1.57-9.70, P = 0.003) were independent predictors of poor functional outcome at 3 months.

Conclusion

Careful management of patients with the above predictive factors may reduce CSDH reoperation and improve long-term functional outcomes. However, larger randomized studies are necessary to assess long-term prognosis after surgical evacuation.

EphrinB2 knockdown in cervical spinal cord preserves diaphragm innervation in a mutant SOD1 mouse model of ALS

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by motor neuron loss. Importantly, non-neuronal cell types such as astrocytes also play significant roles in disease pathogenesis. However, mechanisms of astrocyte contribution to ALS remain incompletely understood. Astrocyte involvement suggests that transcellular signaling may play a role in disease. We examined contribution of transmembrane signaling molecule ephrinB2 to ALS pathogenesis, in particular its role in driving motor neuron damage by spinal cord astrocytes. In symptomatic SOD1-G93A mice (a well-established ALS model), ephrinB2 expression was dramatically increased in ventral horn astrocytes. Reducing ephrinB2 in the cervical spinal cord ventral horn via viral-mediated shRNA delivery reduced motor neuron loss and preserved respiratory function by maintaining phrenic motor neuron innervation of diaphragm. EphrinB2 expression was also elevated in human ALS spinal cord. These findings implicate ephrinB2 upregulation as both a transcellular signaling mechanism in mutant SOD1-associated ALS and a promising therapeutic target.

Nanoscale rules governing the organization of glutamate receptors in spine synapses are subunit specific

Heterotetrameric glutamate receptors are essential for the development, function, and plasticity of spine synapses but how they are organized to achieve this is not known. Here we show that the nanoscale organization of glutamate receptors containing specific subunits define distinct subsynaptic features. Glutamate receptors containing GluA2 or GluN1 subunits establish nanomodular elements precisely positioned relative to Synaptotagmin-1 positive presynaptic release sites that scale with spine size. Glutamate receptors containing GluA1 or GluN2B specify features that exhibit flexibility: GluA1-subunit containing AMPARs are found in larger spines, while GluN2B-subunit containing NMDARs are enriched in the smallest spines with neither following a strict modular organization. Given that the precise positioning of distinct classes of glutamate receptors is linked to diverse events including cell death and synaptic plasticity, this unexpectedly robust synaptic nanoarchitecture provides a resilient system, where nanopositioned glutamate receptor heterotetramers define specific subsynaptic regions of individual spine synapses.

Glutamate receptors comprise two obligate subunits and two subunits that confer distinct properties and functions to the specific tetramers, which also localize to distinct synaptic spines. Here, the authors use STimulated Emission Depletion nanoscopy (STED) to provide detailed insights into the spatial organization of glutamate receptor types.

Atomoxetine facilitates attentional set shifting in adolescent rats

Adolescent rats show immaturities in executive function and are less able than adult rats to learn reinforcement reversals and shift attentional set. These two forms of executive function rely on the functional integrity of the orbitofrontal and prelimbic cortices respectively. Drugs used to treat attention deficit disorder, such as atomoxetine, that increase cortical catecholamine levels improve executive functions in humans, non-human primates and adult rats with prefrontal lesions. Cortical noradrenergic systems are some of the last to mature in primates and rats. Moreover, norepinephrine transporters (NET) are higher in juvenile rats than adults. The underdeveloped cortical noradrenergic system and higher number of NET are hypothesized to underlie the immaturities in executive function found in adolescents. We assessed executive function in male Long-Evans rats using an intra-dimensional/extradimensional set shifting task. We administered the NET blocker, atomoxetine (0.0, 0.1, 0.9 mg/kg/ml; i.p.), prior to the test of attentional set shift and a reinforcement reversal. The lowest dose of drug facilitated attentional set shifting but had no effect on reversal learning. These data demonstrate that NET blockade allows adolescent rats to more easily perform attentional set shifting.

Preservice elementary teacher's attitudes toward gay and lesbian parenting

This preliminary investigation assessed preservice elementary teacher's attitudes toward homosexual parents and their children. The study populations included 195 college students enrolled in an elementary school health methods course at a large northeastern university. A 51-item " and Lesbian Parenting Questionnaire" was used for data collection purposes. Reliability estimates for the scales were: attitudes toward lesbians and gay men (alpha = .90), comfort toward gay and lesbian families (alpha = .92), and knowledge about homosexuality (alpha = .52). Most respondents agreed gay men: were not disgusting, should be allowed to teach, were not perverted, and should not overcome their feelings of homosexuality. Most respondents disagreed lesbians cannot fit into society or were sick. Nearly all agreed female homosexuality should not be a basis for job discrimination. Females were significantly (p < .001) more comfortable with gay or lesbian parents and their children than were males. Females had significantly (p < .01) more favorable attitudes toward gay fathers than did male respondents. Respondents with stronger religious attitudes had significantly (p < .01) more negative attitudes toward lesbian parents than respondents with weaker religious attitudes.

Effect of instruction on perceived physical ability and exercise adherence

The preliminary findings on the effectiveness of instruction on perceived physical ability and attrition among 53 adult women registered in an 8-wk. structured aerobic exercise program are provided.

Knowledge of anatomy and physiology as a determinant of biofeedback performance

In an extension of a previous experiment by Zappala (1970), prior training in anatomy and physiology was investigated as a determinant of frontal EMG biofeedback performance. Fourteen subjects with no college coursework in anatomy and physiology and little demonstrated knowledge of anatomy and physiology were compared with fifteen college students with coursework and demonstrated knowledge of anatomy and physiology. Each subject completed 11 sessions. Sessions one through three were baseline sessions, while sessions 4-11 included an initial (5-minute) baseline, followed by three (4-minute) biofeedback periods. The results indicated no differences in EMG performance among the two subject groups. Significant reductions in EMG were obtained over feedback sessions, and the four male subjects obtained lower levels of EMG than the 25 female subjects.

Successive spatial discrimination reversals in the prairie dog

Six prairie dogs (Cynomys ludovicianus) were given reversal training on a spatial discrimination reversal task in a Wisconsin General Test Apparatus (WGTA). As with many other species, more errors occurred on the first reversal problem than during acquisition of the original discrimination. However, performance improved over training until each S eventually reversed after a single nonreinforced error. Initial findings indicate that prairie dogs perform at high levels in discrimination learning experiments and could be valuable subjects for psychological research.

Habituation of Electrically Induced Readiness to Gnaw

Electrical stimulation of the hypothalamus in prairie dogs (Cynomys ludovicianus) produced a readiness to gnaw which decreased over time, exhibited spontaneous recovery, and could be dishabituated by foot shock. The response decrement was in part habituatory and could modify the interaction between a stimulation-induced readiness to gnaw and a physiologically induced hunger. Functional plasticity of stimulation-induced behavior might be accounted for, in part, by habituation.