Disentangling the effects of phonation and articulation: Hemispheric asymmetries in the auditory N1m response of the human brain

Background  

The cortical activity underlying the perception of vowel identity has typically been addressed by manipulating the first and second formant frequency (F1 & F2) of the speech stimuli. These two values, originating from articulation, are already sufficient for the phonetic characterization of vowel category. In the present study, we investigated how the spectral cues caused by articulation are reflected in cortical speech processing when combined with phonation, the other major part of speech production manifested as the fundamental frequency (F0) and its harmonic integer multiples. To study the combined effects of articulation and phonation we presented vowels with either high (/a/) or low (/u/) formant frequencies which were driven by three different types of excitation: a natural periodic pulseform reflecting the vibration of the vocal folds, an aperiodic noise excitation, or a tonal waveform. The auditory N1m response was recorded with whole-head magnetoencephalography (MEG) from ten human subjects in order to resolve whether brain events reflecting articulation and phonation are specific to the left or right hemisphere of the human brain.     

Isoxazolyl-serine-based agonists of peroxisome proliferator-activated receptor: design, synthesis, and effects on cardiomyocyte differentiation

The peroxisome proliferator-activated receptors (PPARs) are important molecular targets for the development of drugs for the treatment of human metabolic diseases, inflammation, and cancer. They are known to be activated by a variety of structurally diverse compounds. Using a structure-based drug design approach, we designed and synthesized a series of novel isoxazolyl-serine-based PPAR ligands possessing moderate affinities. Some of the new PPAR ligands were able to stimulate cardiomyocyte differentiation from murine ES cells. Ligand 1a was the most active one tested at concentrations between 1.25 to 20 muM between days 2-6, coinciding with the period when mesodermal cells can be recruited to become cardiomyocytes. Notably, the known PPARalpha, gamma, and delta agonists tested, e.g., fenofibrate, rosiglitazone, and GW501516, were inactive in this assay.