Transient Neuronal Populations Are Required to Guide Callosal Axons: A Role for Semaphorin 3C

Neurons, glia, and callosal axons operate as a “ménage à trois” in the development of the corpus callosum

Further examination of the measurement properties of Leifer & McGannon\u27s (1986) goal acceptance and goal commitment scales

The factor structure and discriminant validity of the Leifer & McGannon (1986) Goal Acceptance and Goal Commitment Scales were examined with structural equation modelling and a sample of employees (N = 196) who participated in a 2-year goal-setting programme. Confirmatory factor analysis indicated that the Goal Acceptance and Goal Commitment Scales measured two factorially distinct constructs. Internal consistency reliabilities were .81 for the Goal Acceptance Scale and .88 for the Goal Commitment Scale. Structural equation analysis indicated that both scales related positively to performance but differentially related to participation, satisfaction with supervision and goal difficulty

Exposure to Di-2-Ethylhexylphthalate Affects Blood Pressure and Electrocardiograms in Mice.

Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer that is used in the manufacturing of FDA approved medical devices and consumer products that employ polyvinyl chloride (PVC) (1). DEHP can comprise up to 40% of the total weight of intravenous bags, and up to 80% of medical tubing. DEHP concentrations can reach 200-300 μg/mL in blood storage bags. Previous studies have identified a link between DEHP exposure and alterations in cardiomyocyte function in vitro; this study aimed to determine the adverse effects of DEHP in an in vivo model using a clinically relevant exposure. Radiotelemetry transmitters (DSI) were surgically implanted into male C57/BL/6 mice (n=8) to record blood pressure and electrocardiograms in freely moving animals. Briefly, the transmitter catheter was placed in the carotid artery to measure blood pressure and biopotential leads were routed subcutaneously to collect an ECG signal. After post-surgical recovery, animals were placed on a control diet or exposed to 200 mg/kg/day DEHP for 4-8 weeks via drinking water. Blood pressure and ECG signals were collected continuously via receivers positioned underneath the animal cages. Data was collected via DSI Dataquest A.R.T., and ECG parameters were analyzed via Ponemah software. Data analysis was performed using Graphpad (Student’s t-test) with significance determined at p\u3c0.05. No significant changes were noted in animal weight, heart weight, water consumption or behavior. A significant increase in systolic blood pressure was observed in the DEHP-treated animals (145± 3 mmHg) compared to the control animals (136 ± 1 mmHg). In the DEHP-treated animals there were notable increases in diastolic pressure (119 ± 5 mmHg) and mean arterial pressure (132 ± 3 mmHg). The control animals had diastolic and mean arterial pressures of 107 ± 2 and 121 ± 2mmHg respectively. We also observed significant slowing in electrical conduction between the atria and ventricle, as determined by ECG PR interval time, in DEHP-treated animals. PR interval time was 42.6 ± 0.4 ms in DEHP-treated animals versus 39.3 ± 1.1 ms in controls. However, no significant changes to QRS complex were observed. Previous reports have demonstrated that DEHP has a diminishing affect on cardiac contractility, suggesting these changes in blood pressure are possibly caused by alterations in sympathetic tone and/or increased vascular resistance. Results of comprehensive in vivo studies are necessary to guide the regulation and utilization of DEHP in medical devices

Evaluation of an angiotensin Type 1 receptor blocker on the reconsolidation of fear memory

© 2020, The Author(s). Inhibition of the angiotensin type 1 receptor (AT1R) has been shown to decrease fear responses in both humans and rodents. These effects are attributed to modulation of extinction learning, however the contribution of AT1R to alternative memory processes remains unclear. Using classic Pavlovian conditioning combined with radiotelemetry and whole-genome RNA sequencing, we evaluated the effects of the AT1R antagonist losartan on fear memory reconsolidation. Following the retrieval of conditioned auditory fear memory, animals were given a single intraperitoneal injection of losartan or saline. In response to the conditioned stimulus (CS), losartan-treated animals exhibited significantly less freezing at 24 h and 1 week; an effect that was dependent upon memory reactivation and independent of conditioned cardiovascular reactivity. Using an unbiased whole-genome RNA sequencing approach, transcriptomic analysis of the basolateral amygdala (BLA) identified losartan-dependent differences in gene expression during the reconsolidation phase. These findings demonstrate that post-retrieval losartan modifies behavioral and transcriptomic markers of conditioned fear memory, supporting an important regulatory role for this receptor in reconsolidation and as a potential pharmacotherapeutic target for maladaptive fear disorders such as PTSD

Angiotensin II Type 2 Receptor-Expressing Neurons in the Central Amygdala Influence Fear-Related Behavior

BACKGROUND: The renin-angiotensin system has been implicated in posttraumatic stress disorder; however, the mechanisms responsible for this connection and the therapeutic potential of targeting the renin-angiotensin system in posttraumatic stress disorder remain unknown. Using an angiotensin receptor bacterial artificial chromosome (BAC) and enhanced green fluorescent protein (eGFP) reporter mouse, combined with neuroanatomical, pharmacological, and behavioral approaches, we examined the role of angiotensin II type 2 receptor (AT METHODS: Dual immunohistochemistry with retrograde labeling was used to characterize AT RESULTS: AT CONCLUSIONS: These findings suggest that CeM A

A reverse signaling pathway downstream of Sema4A controls cell migration via Scrib

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