Mechanical stimulation, response

Psychostimulants. Figure 2 Dopamine molecules have two different possible targets. Both ways are initially increased by DAT inhibition caused by methylphenidate pre- and postsynaptic dopamine receptors. Stimulation of postsynaptic receptors results in inhibition of presynaptic action potential generation. On the other hand, presynaptic receptor stimulation leads to a transmission inhibition of action potentials. Therefore, both mechanisms are responsible for a decrease in vesicular depletion of dopamine into the synaptic cleft (adapted from [2]). 

Hydrogen ions accumulate in tissue damaged by inflammation and ischaemia and so pH is lowered. These protons may activate nociceptors directly via their own family of ion channels as well as sensitising them to mechanical stimulation. Acid-sensing ion channels (ASICS) are a family of sodium channels that are activated by protons — of special interest is one type found only in small dorsal root ganglion neurons that possibly are responsible for activation of nociceptors. Although the transduction of mechanical stimuli is poorly understood, ASICs are closely related to channels that respond to stretch. 

Carlton SM, Hargett GL (1995) Treatment with the NMDA antagonist memantine attenuates nociceptive responses to mechanical stimulation in neuropathic rats. Netuosci Lett 198 115-118... 

Following inflammation there is a 10-fold increase in axons expressing AMPA or kainate receptors (Coggeshall and Carlton, 1999). In anaesthetized rats, antagonism of AMPA/kainate receptors inhibits dorsal horn neuronal responses induced by innocuous and noxious mechanical stimulation of a chronically inflamed ankle (Neugebauer et al., 1994). Application of kainate to the rat hindpaw induces activation of primary afferent neurons, an effect that is reduced by the AMPA/kainate antagonist DNQX (Ault and Hildebrand, 1993). 

Carvalho, R.S., Schaffer, J.L. and Gerstenfeld, L.C. (1998) Osteoblasts induce osteo-pontin expression in response to attachment on fibronectin demonstration of a common role for integrin receptors in the signal transduction processes of cell attachment and mechanical stimulation. Journal of Cellular Biochemistry 70 376-390... 

Salter, D.M., Robb, J.E. and Wright, M.O. (1997) Electrophysiological responses of human bone cells to mechanical stimulation evidence for specific integrin function in mechanotransduction. Journal of Bone and Mineral Research 12 1133-1141... 

The effect of stress on the endocrine and immune systems depends upon its duration and severity. Following acute stress, the rise in ACTH in response to the release of corticotrophin releasing factor (CRF) from the hypothalamus results in a rise in the synthesis and release of cortisol from the adrenals. The increase in the plasma cortisol concentration results in a temporary suppression of many aspects of cellular immunity. Due to the operation of an inhibitory feedback mechanism, stimulation of the central glucocorticoid receptors in the hypothalamus and pituitary causes a decrease in the further release of CRF, thereby decreasing the further... 

Chondrocytes surrounded by a layer of pericellular matrix (PCM) are called chondrons. Understanding the mechanical properties of the PCM is also important in investigating the biological responses of chondrocytes to mechanical stimulation since PCM determines the mechanical environment of the chondrocytes, and may serve as a transducer to... 

Osteoblasts subjected to fluid shear increase expression of the early response gene, c-fos, and the inducible isoform of cyclooxygenase, COX-2, two proteins linked to anabolic response of bone to mechanical stimulation. Flow-induced responses in osteoblasts are mediated by inositol triphosphate intracellular calcium release. Flow-mediated stress is reported to induce both PGE2 and NO production. Fluid shear stress stimulates NO release by two distinct pathways a G-protein and calcium-dependent phase sensitive to flow gradients, and a G-protein and calcium-independent pathway stimulated by sustained flow. 

Dartsch PC, Hammerle H. Orientation response of arterial smooth muscle cells to mechanical stimulation. Eur J Cell Biol. 1986 41 339-346. 

Vassilev and Radomirov (1992) used an isolated preparation of rat rectum. The rectal region, 1-6 cm proximal to the anal sphincter was removed and a 20 mm long segment suspended in an organ bath. The influence of prostaglandins and antagonists on spontaneous mechanical activity and electrically stimulated responses was investigated. 

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