Does Domain-General Auditory Processing Uniquely Explain the Outcomes of Second Language Speech Acquisition, Even Once Cognitive and Demographic Variables are Accounted For?

Extending the paradigm in L1 acquisition, scholars have begun to investigate whether participants’ domain-general ability to represent, encode, and integrate spectral and temporal dimensions of sounds (i.e., auditory processing) could be a potential determinant of the outcomes of post-pubertal L2 speech learning. The current study set out to test the hypothesis that auditory processing makes a unique contribution to L2 speech acquisition for 70 Japanese classroom learners of English with different levels of L2 proficiency when biographical backgrounds (length of instruction and immersion) and memory abilities (working, declarative, and procedural memory) are controlled for. Auditory processing loaded onto modality-general capacities to represent and incorporate anchor stimuli (relative to target stimuli) into long-term memory in an implicit fashion, but dissociated from explicit abilities to remember, associate, and elaborate sensory information. Auditory processing explained a small-to-medium amount of variance in L2 speech learning, even after the other potentially confounding variables were statistically factored out

Endothelial dysfunction in the early- and late-stage type-2 diabetic Goto-Kakizaki rat aorta

As there are increasing evidences that human diabetes induces cardiovascular dysfunction, we investigated the type-2 diabetes-induced endothelial dysfunction in the early and late-stage Goto-Kakizaki (GK) rat aorta. We performed organ bath studies, and examined the changes in expression levels of muscarinic M(3) receptor, endothelial, inducible, and neuronal nitric oxide synthase (eNOS, iNOS, and nNOS, respectively) mRNAs in the rat aorta utilizing real-time polymerase chain reaction in 12-week-old and 70-week-old GK rats as well as in age-matched Wistar rats. In the 12-week-old GK rat aorta, a significant increase in norepinephrine-induced contraction and a significant decrease in acetylcholine-induced relaxation as well as significant increases in expression levels of muscarinic M(3) receptor and eNOS and a significant decrease in nNOS mRNAs were observed compared to age-matched controls. In the older GK rat aorta, significant decreases in acetylcholine- and nitroglycerine-induced relaxations as well as significant decreases in the expression levels of muscarinic M(3) receptor, eNOS, iNOS, and nNOS mRNAs were observed compared to those in the younger GK rats. In contrast, although significant decreases in acetylcholine and nitroglycerine-induced relaxations were observed, the expression levels of muscarinic M(3) receptor, eNOS, iNOS, and nNOS mRNAs in the older Wistar rats aorta were unchanged, increased, increased and decreased, respectively, compared to the younger Wistar rat aorta. These results indicate that endothelial dysfunction in the rat aorta progresses with age and development of diabetes condition, and that decreased relaxations in the late-stage rat aorta may be due to these alterations

Bladder dysfunction after acute urinary retention in the rats: a novel over active bladder model.

As there is increasing evidence that benign prostatic hyperplasia and its related acute urinary retention (AUR) induce over active bladder (OAB) syndrome, we investigated the effects of AUR on bladder function over a 4-week period in a rat model. Ten-week-old female Sprague-Dawley rats were used in this study. AUR was induced by clamping the distal urethra of each rat with a small clip, and then infusing 3 ml (0.6 ml/min) of saline with an infusion pump through a transurethral catheter (22G). The obstruction was sustained for 60 min and the clip was removed and then the bladder was allowed to drain through the catheter. The bladder function was estimated by voiding behavior studies (at 3 days, 1, 2, 3, and 4 weeks), cystometric studies (at 2 and 4 weeks) and organ bath studies using KCl and carbachol (at 2 and 4 weeks). Furthermore, we evaluated histological changes in the rat bladder 2 and 4 weeks after the induction of AUR. The same parameters were also measured in non-AUR rats (control group). The rat bladder weight in the AUR group at 2 weeks was significantly larger than that of the controls, and returned to the control level 4 weeks after the AUR episode. The voiding behavior studies showed significant increase in micturition frequency per day and decrease in single voiding volume 3 days after the induction of AUR, and this voiding behavior was continued for more than 2 weeks. The cystometric studies showed a significant decrease in single-voided volume at 2 weeks rat. However, no significant changes of the other parameters were observed in the rats. The histological studies showed significant infiltration of neutrophils and lymphocytes, as well as increase in turnover of epithelium in AUR rats at 2 weeks, while significant increases in fibrosis in submucosal layer were observed in AUR rats at 4 weeks. This study demonstrated that bladder dysfunction in the rat model caused by AUR needs more than 2 weeks of recovery period. The AUR-associated alterations in the bladder may represent a key clue to understand the underlying pathophysiological mechanisms, which take place in OAB syndrome