Effects of Deep Brain Stimulation on Pausing During Spontaneous Speech in Parkinson's Disease.

The present study examined pausing patterns in spontaneous speech as a measure of the effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) on parkinsonian speech. Pauses reflect various aspects of speech and language processes, including motor initiation and linguistic planning. Relatively little attention has been given to pauses in determining the effect of STN-DBS. An examination of pausing may be helpful to understanding how this form of therapy affects these behaviors. Seven individuals with Parkinson's disease who received surgery for bilateral STN-DBS participated. Spontaneous speech samples were elicited in both the ON and OFF STN-DBS condition. Findings indicated that long pauses (250-3000 ms) in spontaneous speech were significantly shorter and more frequent in the STN-DBS ON condition. Furthermore, the proportion of nonlinguistic boundary pauses was significantly greater with stimulation. The findings support previous studies suggesting that speech motor control and lexical retrieval may be affected by STN-DBS.

Time-dependent network analysis reveals molecular targets underlying the development of diet-induced obesity and non-alcoholic steatohepatitis.

Prolonged high-fat diet leads to the development of obesity and multiple comorbidities including non-alcoholic steatohepatitis (NASH), but the underlying molecular basis is not fully understood. We combine molecular networks and time course gene expression profiles to reveal the dynamic changes in molecular networks underlying diet-induced obesity and NASH. We also identify hub genes associated with the development of NASH. Core diet-induced obesity networks were constructed using Ingenuity pathway analysis (IPA) based on 332 high-fat diet responsive genes identified in liver by time course microarray analysis (8 time points over 24 weeks) of high-fat diet-fed mice compared to normal diet-fed mice. IPA identified five core diet-induced obesity networks with time-dependent gene expression changes in liver. These networks were associated with cell-to-cell signaling and interaction (Network 1), lipid metabolism (Network 2), hepatic system disease (Network 3 and 5), and inflammatory response (Network 4). When we merged these core diet-induced obesity networks, Tlr2, Cd14, and Ccnd1 emerged as hub genes associated with both liver steatosis and inflammation and were altered in a time-dependent manner. Further, protein-protein interaction network analysis revealed Tlr2, Cd14, and Ccnd1 were interrelated through the ErbB/insulin signaling pathway. Dynamic changes occur in molecular networks underlying diet-induced obesity. Tlr2, Cd14, and Ccnd1 appear to be hub genes integrating molecular interactions associated with the development of NASH. Therapeutics targeting hub genes and core diet-induced obesity networks may help ameliorate diet-induced obesity and NASH.

Speech characteristics associated with three genotypes of ataxia.

PURPOSE: Advances in neurobiology are providing new opportunities to investigate the neurological systems underlying motor speech control. This study explores the perceptual characteristics of the speech of three genotypes of spino-cerebellar ataxia (SCA) as manifest in four different speech tasks. METHODS: Speech samples from 26 speakers with SCA were perceptually rated by experienced listeners. The genotypes were: SCA1, SCA5, or SCA6. The speech tasks were: diadochokinesis, word repetition, sentence reading, and picture description. The speech samples were rated using two sets of dimensions characterized as primary (e.g., articulation, rate, and rhythm) or secondary (e.g., imprecise consonants, excess and equal stress, and harsh voice). RESULTS: On primary dimensions, SCA6 was the most impaired generally. Articulation was the most severely affected dimension and the diadochokinesis task was most effective in revealing speech impairments. On secondary dimensions, picture description was the task most likely to produce abnormal speech. The SCA groups shared articulatory problems but differed with respect to abnormal voice features. CONCLUSIONS: These results support previous characterizations of ataxic dysarthria, and provide further information about the speech characteristics of genetic subtypes. Task demands affect perceptual ratings. Voice characteristics may be key to differentiating ataxic subtypes. As the genetic disorders that affect speech become better understood, more detailed characterizations of motor control systems should emerge.