The Effect of a Leading Sound on the Local-Field Potentials Elicited by a Trailing Sound in the Rat’s Inferior Colliculus

The perception of one sound can be influenced by another sound in the environment, with the effect dependent on the spectrotemporal and spatial relationship between the sounds. Mechanisms responsible for this perceptual phenomenon is dependent on the integration of neural signals driven by the two ears in brain centers responsible for hearing. The inferior colliculus (IC) as a midbrain structure is important for the processing of acoustic information. To understand why/how the perception of one sound is influenced by another sound, it is important to study how the two sounds interact with each other in generating responses in the IC. In this study, I examined the effect of a leading sound on the responses elicited by a trailing sound in an ensemble of neurons in the IC. Local-field potentials (LFPs) were recorded to reflect responses of neural ensembles. The two sounds were first colocalized at the ear that was contralateral to the recording site. Then the two sounds were then spatially separated. I evaluated whether the influence generated by a leading sound was dependent on the spatial relationship as well as the time gap between the leading and trailing sounds. Results indicated that the LFPs elicited by a trailing sound were suppressed by a leading sound no matter whether the leading sound was at the contralateral or ipsilateral ear. The suppressive effect was larger when a leading sound was presented at the contralateral than the ipsilateral ear. Furthermore, the effect was larger when the two sounds were separated by a short time gap. Inhibitory neurotransmitter antagonists, gabazine and strychnine significantly decreased the suppression produced by the leading sound but did not eliminate it. These results suggest that local inhibitory interaction in the inferior colliculus may not be the only factor that is responsible for the suppressive effect produced by the leading sound. Results from this study are important for understanding neural mechanisms responsible for hearing in a real-world situation

An acoustic investigation of primary and secondary lexical stress of Urdu

This paper investigated acoustic correlates of primary and secondary stress in Urdu language. Urdu is not a sufficiently researched language in the context of lexical stress. A few researches (Mehrotra, 1965; Hussain, 1997; Nair, 1999; Mumtaz, 2014, and Qurrat-Ul-Ain & Mahmood (2017) discussed stress in Urdu/Hindi language. Perhaps, Qurrat-Ul-Ain & Mahmood (2017) study is the first to phonetically document the presence of secondary stress in Urdu using the cue of duration. The present study focused on the four popular acoustic cues of lexical stress to see how Urdu lexical stress (primary as well as secondary) behaves against these cues. The stimuli of the study consist of six tri-syllabic words (embedded with low-back-long vowel /a:/ in all syllables) uttered by nine female Urdu speakers from Lahore. Four popular stress cues (duration, vowel quality, pitch, and intensity) have been analyzed to see their correlation with Urdu lexical stress. The analysis reveals three levels of lexical stress: primary, secondary, and unstressed. Vowel duration is the strongest cue to correlate with the levels of stress in Urdu while stressed segments prone to have higher values of intensity. Overall, a trend of lower F0 and higher formant values could be seen against stressed syllables. The study, however, needs to be expanded further by using words having other vowel sounds. Moreover, the phenomenon of word final lengthening can be taken into account in the potential researches

Metastasis of lung adenocarcinoma to the pituitary gland

Pituitary metastasis (PM) is rare occurrence and accounts for <1% of all intracranial metastatic lesions. In this study, we highlight the importance of considering atypical sites for lung adenocarcinoma metastasis by presenting a case of a 54-year-old male who was diagnosed with PM 15 months after being diagnosed with stage IV lung adenocarcinoma with metastasis to the spine, pelvis, left frontal lobe, and right occipital lobe. He was on a prolonged course of chemotherapy during those 15 months and received palliative radiation for his brain metastasis with subsequent remission after 5 months following his initial diagnosis. The pituitary lesion was picked up as an incidental finding on a routine staging magnetic resonance imaging (MRI) 10 months after his brain metastasis remission. The patient successfully underwent trans-sphenoidal pituitary lesion resection. This case emphasizes the importance of routine surveillance and examination of atypical sites of metastasis even in patients undergoing a prolonged course of chemotherapy

Health-status outcomes with invasive or conservative care in coronary disease

BACKGROUND In the ISCHEMIA trial, an invasive strategy with angiographic assessment and revascularization did not reduce clinical events among patients with stable ischemic heart disease and moderate or severe ischemia. A secondary objective of the trial was to assess angina-related health status among these patients. METHODS We assessed angina-related symptoms, function, and quality of life with the Seattle Angina Questionnaire (SAQ) at randomization, at months 1.5, 3, and 6, and every 6 months thereafter in participants who had been randomly assigned to an invasive treatment strategy (2295 participants) or a conservative strategy (2322). Mixed-effects cumulative probability models within a Bayesian framework were used to estimate differences between the treatment groups. The primary outcome of this health-status analysis was the SAQ summary score (scores range from 0 to 100, with higher scores indicating better health status). All analyses were performed in the overall population and according to baseline angina frequency. RESULTS At baseline, 35% of patients reported having no angina in the previous month. SAQ summary scores increased in both treatment groups, with increases at 3, 12, and 36 months that were 4.1 points (95% credible interval, 3.2 to 5.0), 4.2 points (95% credible interval, 3.3 to 5.1), and 2.9 points (95% credible interval, 2.2 to 3.7) higher with the invasive strategy than with the conservative strategy. Differences were larger among participants who had more frequent angina at baseline (8.5 vs. 0.1 points at 3 months and 5.3 vs. 1.2 points at 36 months among participants with daily or weekly angina as compared with no angina). CONCLUSIONS In the overall trial population with moderate or severe ischemia, which included 35% of participants without angina at baseline, patients randomly assigned to the invasive strategy had greater improvement in angina-related health status than those assigned to the conservative strategy. The modest mean differences favoring the invasive strategy in the overall group reflected minimal differences among asymptomatic patients and larger differences among patients who had had angina at baseline

Initial invasive or conservative strategy for stable coronary disease

BACKGROUND Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, 121.8 percentage points; 95% CI, 124.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used