Recognition of temporarily modified speech stimuli

This paper studies the relationship between consonant duration and recognition of these consanants by listeners with high frequency hearing loss.

Habituation of the immobility response of guinea pigs to auditory stimuli

This paper discusses the development of a method to measure the habituation of the immobility response of guinea pigs.

Cross-modality temporal resolution for auditory, vibrotactile, and visual stimuli

This paper reviews a study of cross-modalities and within-modalities and their effects on speech perception.

Acoustic reflex measurements in normals and Meniere's Syndrome using pulsed stimuli

This paper reviews a study to determine the maximum rate the acoustic reflex can follow pulsed stimuli in normal hearing subjects and in subjects with Meniere's Syndrome.

The slow cortical evoked potential: cross modality interaction of auditory, vibro-tactile and shock stimuli

This paper discusses a study that collected cortical evoked responses when stimuli of different modalities were presented.

Myocyte remodeling in response to hypertrophic stimuli requires nucleocytoplasmic shuttling of muscle LIM protein

CSRP3 or muscle LIM protein (MLP) is a nucleocytoplasmic shuttling protein and a mechanosensor in cardiac myocytes. MLP regulation and function was studied in cultured neonatal rat myocytes treated with pharmacological or mechanical stimuli. Either verapamil or BDM decreased nuclear MLP while phenylephrine and cyclic strain increased it. These results suggest that myocyte contractility regulates MLP subcellular localization. When RNA polymerase II was inhibited with alpha-amanitin, nuclear MLP was reduced by 30%. However, when both RNA polymerase I and II were inhibited with actinomycin D, there was a 90% decrease in nuclear MLP suggesting that its nuclear translocation is regulated by both nuclear and nucleolar transcriptional activity. Using cell permeable synthetic peptides containing the putative nuclear localization signal (NLS) of MLP, nuclear import of the protein in cultured rat neonatal myocytes was inhibited. The NLS of MLP also localizes to the nucleolus. Inhibition of nuclear translocation prevented the increased protein accumulation in response to phenylephrine. Furthermore, cyclic strain of myocytes after prior NLS treatment to remove nuclear MLP resulted in disarrayed sarcomeres. Increased protein synthesis and brain natriuretic peptide expression were also prevented suggesting that MLP is required for remodeling of the myo filaments and gene expression. These findings suggest that nucleocytoplasmic shuttling MLP plays an important role in the regulation of the myocyte remodeling and hypertrophy and is required for adaptation to hypertrophic stimuli. (C) 2009 Elsevier Inc. All rights reserved.

Skeletal muscle fibre plasticity in response to selected environmental and physiological stimuli

Skeletal muscle constitutes a highly adaptable and malleable tissue that responds to environmental and physiological challenges by changing its phenotype in terms of size and composition, outcomes that are brought about by changes in gene expression, biochemical and metabolic properties. Both the short- and long-term effects of nutritional alterations on skeletal muscle homeostasis have been defined as the object of intensive research over the last thirty years. This review focuses predominantly on assimilating our understanding of the changes in muscle fibre phenotype and functional properties induced by either food restriction or alternatively existing on a high fat diet. Firstly, food restriction has been shown in a number of studies to decrease the myofibre cross sectional area and consistently, it has been found that glycolytic type IIB fibres are more prone to atrophy than oxidative fibres. Secondly, in rodents, a high fat diet has been shown to induce an oxidative profile in skeletal muscle, although obese humans usually show higher numbers of glycolytic type IIB fibres. Moreover, attention is paid to the effect of prenatal maternal food restriction on muscle development of the offspring in various species. A key point related to these experiments is the timing of food restriction for the mother. Furthermore, we explore extensively the seemingly species-specific response to maternal malnutrition. Finally, key signalling molecules that play a pivotal role in energy metabolism, fibre type transitions and muscle hypertrophy are discussed in detail.

The Ca(v)2.3 calcium channel antagonist SNX-482 reduces dorsal horn neuronal responses in a rat model of chronic neuropathic pain

Neuropathic pain is a difficult state to treat, characterized by alterations in sensory processing that can include allodynia (touch-evoked pain). Evidence exists for nerve damage-induced plasticity in both transmission and modulatory systems, including changes in voltage-dependent calcium channel (VDCC) expression and function; however, the role of Ca(v)2.3 calcium channels has not clearly been defined. Here, the effects of SNX-482, a selective Ca(v)2.3 antagonist, on sensory transmission at the spinal cord level have been investigated in the rat. The spinal nerve ligation (SNL) model of chronic neuropathic pain [Kim & Chung, (1992) Pain, 50, 355-363] was used to induce mechanical allodynia, as tested on the ipsilateral hindpaw. In vivo electrophysiological measurements of dorsal horn neuronal responses to innocuous and noxious electrical and natural stimuli were made after SNL and compared to sham-operated animals. Spinal SNX-482 (0.5-4 mu g/50 mu L) exerted dose-related inhibitions of noxious C-fibre- and A delta-fibre-mediated neuronal responses in conditions of neuropathy, but not in sham-operated animals. Measures of spinal cord hyperexcitability and nociception were most susceptible to SNX-482. In contrast, non-noxious A beta-mediated responses were not affected by SNX-482. Moreover, responses to innocuous mechanical and also thermal stimuli were more sensitive to SNX-482 in SNL than control animals. This study is the first to demonstrate an antinociceptive role for SNX-482-sensitive channels in dorsal horn neurons during neuropathy. These data are consistent with plasticity in Ca(V)2.3 calcium channel expression and suggest a potential selective target to reduce nociceptive transmission during conditions of nerve damage.

The primary somatosensory cortex largely contributes to the early part of the cortical response elicited by nociceptive stimuli.

Research on the cortical sources of nociceptive laser-evoked brain potentials (LEPs) began almost two decades ago (Tarkka and Treede, 1993). Whereas there is a large consensus on the sources of the late part of the LEP waveform (N2 and P2 waves), the relative contribution of the primary somatosensory cortex (S1) to the early part of the LEP waveform (N1 wave) is still debated. To address this issue we recorded LEPs elicited by the stimulation of four limbs in a large population (n=35). Early LEP generators were estimated both at single-subject and group level, using three different approaches: distributed source analysis, dipolar source modeling, and probabilistic independent component analysis (ICA). We show that the scalp distribution of the earliest LEP response to hand stimulation was maximal over the central-parietal electrodes contralateral to the stimulated side, while that of the earliest LEP response to foot stimulation was maximal over the central-parietal midline electrodes. Crucially, all three approaches indicated hand and foot S1 areas as generators of the earliest LEP response. Altogether, these findings indicate that the earliest part of the scalp response elicited by a selective nociceptive stimulus is largely explained by activity in the contralateral S1, with negligible contribution from the secondary somatosensory cortex (S2).