scholarly journals Mechanical and thermal stimuli-induced release of toluene included in luminescent crystals as one-dimensional solvent channels

2020 ◽  
Vol 8 (29) ◽  
pp. 10039-10046 ◽  
Author(s):  
Yoshimitsu Sagara ◽  
Kiyonori Takahashi ◽  
Takayoshi Nakamura ◽  
Nobuyuki Tamaoki
Keyword(s):  
Organic Crystals ◽  
Mechanical Stimuli ◽  
One Dimensional ◽  
Thermal Stimuli

Thermal and mechanical stimuli-induced release of toluene from luminescent organic crystals is described.

Unmyelinated nociceptors of rat paraspinal tissues

1995 ◽  
Vol 73 (5) ◽  
pp. 1752-1762 ◽  
Author(s):  
G. M. Bove ◽  
A. R. Light
Keyword(s):  
Lumbar Spine ◽  
Intact Animal ◽  
Receptive Fields ◽  
Clinical Importance ◽  
Mechanical Stimuli ◽  
Peripheral Neuropathies ◽  
Deep Tissue ◽  
Surrounding Connective Tissue ◽  
Thermal Stimuli ◽  
Stimulation Of

1. We made recordings from rat dorsal root filaments to study unmyelinated afferent units (conduction velocity < or = 1.5 m/s) associated with deep paraspinal tissues of the dorsal sacrum and proximal tail. Data from 57 unmyelinated units were analyzed in 47 experiments. Receptive fields were identified in intact animals and then surgically isolated using microdissection. Units were characterized using mechanical, noxious chemical, and thermal stimuli. 2. These recordings revealed innervation of the nerve sheaths and surrounding connective tissue, muscles, tendons, and tissue apposed to the undersurface of the skin. No units were found with receptive fields directly on joint capsular tissue. The receptive fields of the units were often multiple and located in more than one tissue; 31 of 57 units showed convergence from different tissues. 3. The units with receptive fields on neurovascular bundles shared sensitivities with other deep tissue units described in this and other reports. These units may have clinical importance in pain due to peripheral neuropathies. 4. The units initially responded to strong mechanical stimulation of the intact animal and often to noxious stretch of the tail. Once surgically isolated, an individual unit's threshold to mechanical stimuli appeared lower. 5. Capsaicin (0.001%-0.1%) elicited responses in 81% (17 of 21) of the units tested. Bradykinin (20 micrograms/ml) elicited responses in 45% (10 of 22) of the units tested. Noxious cold (4-10 degrees C) and hot (55 degrees C) stimulation elicited discharges from 33% (5 of 15) and 25% (5 of 20) of the units tested, respectively. 6. The unmyelinated units had similar mechanical, chemical, and thermal sensitivities. These similarities and the observed convergence only allowed separation of units by the tissue in which the ending was found, and did not allow further classification. 7. The prevalence of background discharge suggested that many units were sensitized during the experiments. 8. The sensitivities of these paraspinal units were similar to those reported for other tissues. Because of the anatomic similarity of the paraspinal tissues of the proximal tail and the lumbar spine, the conclusions of the present study can be related to the lumbar spine. These afferent units are thought to participate in nociception from the deep paraspinal tissues.

Responses of spinothalamic tract cells to mechanical and thermal stimulation of skin in rats with experimental peripheral neuropathy

1992 ◽  
Vol 67 (6) ◽  
pp. 1562-1573 ◽  
Author(s):  
J. Palecek ◽  
V. Paleckova ◽  
P. M. Dougherty ◽  
S. M. Carlton ◽  
W. D. Willis
Keyword(s):  
Dynamic Range ◽  
Background Activity ◽  
Thermal Stimulation ◽  
Spontaneous Pain ◽  
Mechanical Stimuli ◽  
Spinothalamic Tract ◽  
High Background ◽  
Threshold Temperatures ◽  
Thermal Stimuli ◽  
Stimulation Of

1. Responses of spinothalamic tract (STT) neurons to mechanical and thermal stimulation of skin were recorded under urethane and pentobarbital anesthesia in 12 control rats and in 20 rats with experimental neuropathy. Activity of the STT cells in neuropathic rats was recorded 7, 14, and 28 days after inducing the neuropathy by placing four loose ligatures on the sciatic nerve. 2. All neuropathic animals showed guarding of the injured hindpaw and a shorter withdrawal latency from a radiant heat source of the neuropathic hindpaw than that of the sham-operated paw. 3. STT neurons in neuropathic animals showed the most profound changes 7 and 14 days after the nerve ligation. When compared with STT cells in unoperated animals, approximately half of the neurons had high background activity, responses to innocuous stimuli represented a larger percentage of the total evoked activity in wide dynamic range neurons, and the occurrence and magnitude of afterdischarges to mechanical and thermal stimuli were increased. 4. The mean threshold temperatures of heat-evoked responses of the STT cells in neuropathic animals were not different than those of cells from control animals. However, in neuropathic rats, cells reacting to small heat stimuli usually already had afterdischarges. 5. The increase in the background activity of STT cells is consistent with behavioral observations of spontaneous pain in this model of experimental neuropathy. Furthermore, the afterdischarges of STT cells may parallel the prolonged paw withdrawal in response to noxious stimuli that is seen in these animals and that is evidence for hyperalgesia. However, there was no indication of a lowered threshold for thermal stimuli as might be expected if the animals have thermal allodynia. Mechanical allodynia may have resulted from a relative increase in responsiveness to innocuous mechanical stimuli. However, responses to noxious mechanical stimuli were reduced compared with control, at least at 28 days after the ligation. Peripheral and central mechanisms responsible for the changes in responses of STT cells in neuropathic animals are suggested.

scholarly journals Response characteristics of pruriceptive and nociceptive trigeminoparabrachial tract neurons in the rat

2015 ◽  
Vol 113 (1) ◽  
pp. 58-70 ◽  
Author(s):  
Nico A. Jansen ◽  
Glenn J. Giesler
Keyword(s):  
Discharge Rate ◽  
Receptive Fields ◽  
Behavioral Responses ◽  
Spike Timing ◽  
Mustard Oil ◽  
Mechanical Stimuli ◽  
Firing Rates ◽  
Response Characteristics ◽  
Mapping Techniques ◽  
Thermal Stimuli

We tested the possibility that the trigeminoparabrachial tract (VcPbT), a projection thought to be importantly involved in nociception, might also contribute to sensation of itch. In anesthetized rats, 47 antidromically identified VcPbT neurons with receptive fields involving the cheek were characterized for their responses to graded mechanical and thermal stimuli and intradermal injections of pruritogens (serotonin, chloroquine, and β-alanine), partial pruritogens (histamine and capsaicin), and an algogen (mustard oil). All pruriceptive VcPbT neurons were responsive to mechanical stimuli, and more than half were additionally responsive to thermal stimuli. The majority of VcPbT neurons were activated by injections of serotonin, histamine, capsaicin, and/or mustard oil. A subset of neurons were inhibited by injection of chloroquine. The large majority of VcPbT neurons projected to the ipsilateral and/or contralateral external lateral parabrachial and Kölliker-Fuse nuclei, as evidenced by antidromic mapping techniques. Analyses of mean responses and spike-timing dynamics of VcPbT neurons suggested clear differences in firing rates between responses to noxious and pruritic stimuli. Comparisons between the present data and those previously obtained from trigeminothalamic tract (VcTT) neurons demonstrated several differences in responses to some pruritogens. For example, responses of VcPbT neurons to injection of serotonin often endured for nearly an hour and showed a delayed peak in discharge rate. In contrast, responses of VcTT neurons endured for roughly 20 min and no delayed peak of firing was noted. Thus the longer duration responses to 5-HT and the delay in peak firing of VcPbT neurons better matched behavioral responses to stimulation in awake rats than did those of VcTT neurons. The results indicate that VcPbT neurons may have important roles in the signaling of itch as well as pain.

Polymorphic crystals and their luminescence switching of triphenylacrylonitrile derivatives upon solvent vapour, mechanical, and thermal stimuli

2015 ◽  
Vol 3 (13) ◽  
pp. 3049-3054 ◽  
Author(s):  
Yujian Zhang ◽  
Qingbao Song ◽  
Kai Wang ◽  
Wengang Mao ◽  
Feng Cao ◽  
...  
Keyword(s):  
Organic Crystals ◽  
Yellow Fluorescence ◽  
Solvent Vapour ◽  
Polymorphic Crystals ◽  
Fluorescence Switching ◽  
Thermal Stimuli

The organic crystals BCrys, SCrys and YCrys with the blue, sky-blue, and yellow fluorescence, respectively exhibit the responsive fluorescence switching under grinding, heating and solvent vapour stimulation.

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