• Non-nociceptive and nociceptive-like trigeminal Aβ-afferent neurons of rats: distinct electrophysiological properties, mechanical and chemical sensitivity. (iasp-pain.org)
  • Recently, we have characterized Aβ-afferent neurons which have large diameter somas in the trigeminal ganglion (TG) and classified them into non-nociceptive and nociceptive-like TG afferent neurons based on their electrophysiological properties. (iasp-pain.org)
  • Here, we extend our previous observations to further characterize electrophysiological properties of trigeminal Aβ-afferent neurons and investigate their mechanical and chemical sensitivity by patch-clamp recordings from large-diameter TG neurons in ex vivo TG preparations of adult male and female rats. (iasp-pain.org)
  • Based on cluster analysis of electrophysiological properties, trigeminal Aβ-afferent neurons can be classified into five discrete types (type I, IIa, IIb, IIIa, and IIIb), which responded differentially to mechanical stimulation and sensory mediators including serotonin (5-HT), acetylcholine (ACh) and adenosine triphosphate (ATP). (iasp-pain.org)
  • Together, type I, IIa and IIb display features of LTMR Aβ-afferent neurons while type IIIa and type IIIb show properties of nociceptive Aβ-afferent neurons. (iasp-pain.org)
  • Laminae I and II are sent information from afferent neurons that sense nociception, temperature, and itching, laminae III and IV are sent information from neurons that sense mechanical pressure, and laminae V and VI are sent information from proprioceptors. (wikipedia.org)
  • These neurons mediate the activity of nociceptive and temperature afferent fibers. (wikipedia.org)
  • We used patch-clamp recording in dorsal horn neurons in isolated spinal cord slices to investigate whether PICs have similar or different effects on synaptic transmission in lamina II neurons in which nociceptive information is modulated and conveyed to projection neurons. (jneurosci.org)
  • Central sensitization is a process whereby nociceptive neurons and circuits exhibit increased function in response to activity, inflammation, or injury through a variety of processes that include changes in receptor field size, increases in neuronal excitability, increases in synaptic efficiency/coupling, and changes in neuronal connectivity ( Latremoliere and Woolf, 2009 ). (nature.com)
  • We also examined the neurochemical identity of 5-HT 1D -IR neurons with markers of primary afferent nociceptors, peripherin, isolectin B4, and substance P, and markers of myelinated afferents, N52 and SSEA3. (jneurosci.org)
  • We observed a striking similarity in the size, distribution, and neurochemical identity of 5-HT 1D -IR neurons in TRG and lumbar DRG afferents. (jneurosci.org)
  • Furthermore, the vast majority of 5-HT 1D -IR neurons are unmyelinated peptidergic afferents that distribute peripherally, including the dura, cornea, and the sciatic nerve. (jneurosci.org)
  • The tooth has an unusual sensory system that converts external stimuli predominantly into pain, yet its sensory afferents in teeth demonstrate cytochemical properties of non-nociceptive neurons. (mdpi.com)
  • However, in the mid- to late 1990s, a number of laboratories interested in cold transduction began to use primary cultures of either dorsal root (DRG) or trigeminal (TG) ganglia neurons as in vitro models of sensory afferents. (nih.gov)
  • While the exact mechanisms for vitamin B complex efficacy in the treatment of low back pain are still largely unknown, the prevailing hypothesis involves increasing afferent inhibitory control of nociceptive neurons at the spinal cord, improving sensory nerve conduction velocity and reducing neuronal hyperexcitability by altering sodium currents in injured dorsal root ganglia. (dsm.com)
  • CS is defined as a type of nociplastic pain, with increased nociceptive sensitivity with either normal or sub-threshold afferent input from neurons in the central nervous system. (hcplive.com)
  • According to a study in Rehabilitation Research and Practice , menthol has been found to increase the sensitization of neurons which in turn leads to the perception of coolness, causing an inhibitory effect on non-nociceptive afferents that makes you feel pain. (jointhealthmagazine.com)
  • Two distinct classes of RVM neurons, "ON-cells" and "OFF-cells," exert net pronociceptive and anti-nociceptive effects, respectively. (eneuro.org)
  • These data show that a direct connection from the PB to the RVM conveys nociceptive information to the pain-modulating neurons of RVM under basal conditions. (eneuro.org)
  • Using optogenetics with whole-cell patch-clamp recording and in vivo single-cell recording, the present studies identified direct functional connections from the parabrachial complex (PB), a major target of ascending nociceptive pathways, to physiologically identified pain-modulating neurons of the rostral ventromedial medulla (RVM), the primary output node of a major descending pain-modulating system. (eneuro.org)
  • Here we report that TcdB induces neurogenic inflammation by targeting gut-innervating afferent neurons and pericytes through receptors, including the Frizzled receptors (FZD1, FZD2 and FZD7) in neurons and chondroitin sulfate proteoglycan 4 (CSPG4) in pericytes. (bvsalud.org)
  • The activity of spinal trigeminal neurons with afferent input from the dura mater was recorded in vivo in anesthetised rats. (bvsalud.org)
  • In the primary afferent neurons, GRK2 negatively regulates nociceptive tone. (bvsalud.org)
  • The present study tested the hypothesis that induction of GRK2 in the primary afferent neurons contributes to the resolution of acute pain after tissue injury. (bvsalud.org)
  • Radiant-heat stimuli of different intensities were delivered every 28 s to the thenar eminence of the hand of human subjects and to the receptive fields (RFs) of 58 'mechanothermal nociceptive' and 16 'warm' C-fibers, most of which innervated the glabrous skin of the monkey hand. (johnshopkins.edu)
  • The cumulative number of impulses evoked during each stimulation in the nociceptive afferents increased monotonically as a function of stimulus temperature over the range described by humans as increasingly painful (45-50°C). Nociceptive fibers showed little or no response to stimulus temperatures less than 45°C that elicited in humans sensations primarily of warmth but not pain. (johnshopkins.edu)
  • The sensation of pain is associated with activation of afferent C-fibers found in the skin. (athabascau.ca)
  • This finding suggests the importance of the spatial summation of activity across multiple afferent C-fibers in the perception of pain. (athabascau.ca)
  • The afferent input from these fibers inhibits propagation of nociception carried in the small, unmyelinated C fibers by blocking transmission along these fibers to the target or T cells located in the substantia gelatinosa (laminae 2 and 3) of the dorsal horn. (medscape.com)
  • [ 7 ] The gate usually is closed, inhibiting constant nociceptive transmission via C fibers from the periphery to the T cell. (medscape.com)
  • This theory suggests that stimulation of large (A-beta) afferent cutaneous fibers activate the inhibitory-interneurons in the dorsal horn of de medulla. (biomedcentral.com)
  • This may weaken the transmission of nociceptive signals from small diameter A-delta and C-fibers. (biomedcentral.com)
  • According to the theory, neuromodulation may activate large myelinated afferent nerve fibers in the dorsal horn to inhibit transmission in primary afferent nociceptive fibers. (societyfp.org)
  • Substance P, synthesized by cells of the spinal ganglia, has been identified at the peripheral terminal of unmyelinated primary afferent fibers. (pharmacology2000.com)
  • Consistent with this, in vivo recording showed that nociceptive-evoked responses of ON- and OFF-cells were suppressed by optogenetic inactivation of archaerhodopsin (ArchT)-expressing PB terminals in RVM, demonstrating that a net inhibitory input to OFF-cells and net excitatory input to ON-cells are engaged by acute noxious stimulation. (eneuro.org)
  • Instead, there is evidence that TRPA1 activation may have an inhibitory function in the nociceptive trigeminal system. (bvsalud.org)
  • The role of Aβ-afferents in somatosensory function is often oversimplified as low threshold mechanoreceptors (LTMRs) with large omission of Aβ-afferent involvement in nociception. (iasp-pain.org)
  • While there are relatively few studies examining epigenetically mediated mechanisms involved in visceral nociception, stress-induced visceral pain has been linked to alterations in DNA methylation and histone acetylation patterns within the brain, leading to increased expression of pro-nociceptive neurotransmitters. (frontiersin.org)
  • Somatosensation and nociception are finely mapped and aligned in the adult somatosensory (S1) cortex, but in infancy, when pain behaviour is disorganised and poorly directed, nociceptive maps may be less refined. (elifesciences.org)
  • Recordings of polymodal single c-fiber nociceptive afferents following mechanical and argon-laser heat stimulation of human skin. (athabascau.ca)
  • The results of laboratory studies suggest that electrical stimulation delivered by a TENS unit reduces pain through nociceptive inhibition at the presynaptic level in the dorsal horn, thus limiting its central transmission. (medscape.com)
  • In chronic pain states prolonged nociceptive stimulation causes activation and upregulation of the NMDAR at dorsal horn synapses resulting in enhanced and amplified trafficking of pain signals to the brain (central sensitization). (m4carbine.net)
  • There are specific receptors that respond to intense stimulation (hot, cold, deformations, etc.) and sensory receptors that, under certain conditions, will send a nociceptive message. (post-operative-chronic-pain.com)
  • The amygdala, and more specifically the central nucleus of the amygdala (CeA), is a convergence point for multiple pathways carrying nociceptive information into the central nervous system. (nature.com)
  • CeA projections to periacqueductal gray (PAG) gate descending pathways that modulate nociceptive afferent activity in the dorsal horn of the spinal cord. (nature.com)
  • In summary, unilateral UVB irradiation induced contralateral changes in inflammatory/nociceptive neuropeptides in spinal cord and afferent pathways involved in pain signaling already within 24 h, a time point when also ipsilateral neurochemical/physiological changes have been reported for rats and humans. (lu.se)
  • The CVLM receives nociceptive and cardiovascular responses. (wikipedia.org)
  • PB receives nociceptive input via the spinoparabrachial tract. (eneuro.org)
  • LaMotte, RH & Campbell, JN 1978, ' Comparison of responses of warm and nociceptive C-fiber afferents in monkey with human judgments of thermal pain ', Journal of neurophysiology , vol. 41, no. 2, pp. 509-528. (johnshopkins.edu)
  • The convergence of nociceptive information in CeA is particularly interesting because CeA is the primary output nucleus of the amygdala, and sends projections to effector regions that initiate physiological and behavioral responses to external events, including the response to noxious stimuli ( Gilpin et al, 2015 ). (nature.com)
  • Therefore, under normal physiological conditions, CeA functions as a hub between incoming nociceptive information and nocifensive responses to noxious stimuli. (nature.com)
  • Our finding, that 5-HT 1D receptors are distributed in nociceptors throughout the body, raises the possibility that triptans can regulate not only headache-associated pain but also nociceptive responses in extracranial tissues. (jneurosci.org)
  • Descending pain-modulatory circuits mediate top-downregulation of nociceptive processing, transmitting cortical and limbic influences to the dorsal horn. (eneuro.org)
  • At the level of the primary afferent nerve, the site at which thermal stimuli are converted into neuronal activity, temperature-sensitive members of the TRP channel family are found. (nih.gov)
  • This numerical discrepancy may have distinct functional implications for how triptans modulate afferent activity and emphasizes the importance of knowing the neurochemical properties of the primary afferents bearing the triptan receptors. (jneurosci.org)
  • Neuropeptides released from activated nociceptive afferent nerves play a pivotal role in inflammatory reactions and pain, significantly modulate cardiac, vascular, respiratory, gastrointestinal and immune functions and influence the protective, restorative and trophic functions of somatic and visceral tissues. (elsevier.com)
  • While other mammals have thickly myelinated afferents signaling pain (ultrafast nociceptors), these have not been demonstrated in humans. (ljmu.ac.uk)
  • We compared the distribution of 5-HT 1D receptor-immunoreactive (5-HT 1D -IR) peripheral afferents within the trigeminal ganglion (TRG) and lumbar dorsal root ganglion (DRG) of the rat. (jneurosci.org)
  • We hypothesised that this developmental process is reflected in ascending nociceptive signals to S1, leading to widespread S1 activation and poor spatial localisation of noxious events in early life. (elifesciences.org)
  • The NMDAR is an excitatory glutamatergic receptor present at spinal and supraspinal sites and involved in the afferent transmission of nociceptive signals. (m4carbine.net)
  • Here, we performed single-unit axonal recordings (microneurography) from cutaneous mechanoreceptive afferents in healthy participants. (ljmu.ac.uk)
  • This putative neurotransmitter may play a role in the propagation of visceral nociceptive pain from the gastrointestinal (GI) tract, ureters, and urinary bladder. (pharmacology2000.com)
  • Nociceptive pain (pain caused by tissue injury) may be somatic or visceral. (msdmanuals.com)
  • The cortex also sends polymodal sensory information, including nociceptive information, to CeA via relays in basolateral amygdaloid complex ( Shi and Davis, 1999 ). (nature.com)
  • The subjective magnitude of warmth and pain sensations in humans and the cumulative impulse count evoked by each stimulus in warm and nociceptive afferents varied inversely with the number, delivery rate, and intensity of preceding stimulations. (johnshopkins.edu)
  • The data reveals a widespread cortical nociceptive map in infant S1, consistent with their poorly directed pain behaviour. (elifesciences.org)
  • The authors suggest that, relative to the infant touch somatotopic map, the infant nociceptive map is more widespread and poorly localised, consistent with infants' poorly directed pain behaviour. (elifesciences.org)
  • Ectopic discharge ('ectopia') in damaged afferent axons is a major contributor to chronic neuropathic pain. (researchgate.net)
  • There is now ample evidence that NMDAR antagonists that block the NMDAR, such as ketamine, are able to halt the excessive barrage of nociceptive input to the brain and are therefore potential alternatives to existing treatments of chronic pain syndromes [4,23]. (m4carbine.net)
  • A nociceptive message does not necessarily cause pain and conversely a sensory message can cause pain. (post-operative-chronic-pain.com)
  • These data for the first time point to an identified nociceptive synapse in RVM that could be probed in relevant physiologic contexts, and set the stage for a dissection of the links between nociceptive transmission and nociceptive modulation in the transition from acute to chronic pain. (eneuro.org)
  • However, circuits through which ascending nociceptive information gains access to descending pain-modulatory systems are only now being defined. (eneuro.org)
  • The canonical view is that touch is signaled by fast-conducting, thickly myelinated afferents, whereas pain is signalled by slow-conducting, thinly myelinated ("fast" pain) or unmyelinated ("slow" pain) afferents. (ljmu.ac.uk)
  • These findings demonstrate that human mechanical pain does not require PIEZO2 and can be signaled by fast-conducting, thickly myelinated afferents. (ljmu.ac.uk)
  • The gate-control theory postulates a mechanism by which the gate is closed again, preventing further central transmission of the nociceptive information to the cortex. (medscape.com)
  • It is known to be the primary relay point for haptic and nociceptive messages. (wikipedia.org)
  • Angeli's salt solution (AS, 300 µM) caused short-lasting vigorous increases in neuronal activity of primary meningeal afferents, followed by deactivation and desensitisation. (bvsalud.org)
  • Harding-Forrester and Feldman, 2018 ), and may also convey computational advantages in the relay of afferent information to higher brain areas ( Thivierge and Marcus, 2007 ). (elifesciences.org)
  • PB was recently shown to be a relay of nociceptive information to RVM ON- and OFF-cells. (eneuro.org)
  • One possible explanation for this difference is that 5-HT 1D receptors are preferentially expressed by cranial afferents of the trigeminal system. (jneurosci.org)
  • Serotonin, bradykinin, histamine, prostaglandins, substance P (sP) , and various ions (ie, H + or K + )--the biochemical mediators released as a result of tissue injury--have been implicated in nociceptive activation and sensitization (hyperalgesia). (pharmacology2000.com)
  • The parabrachial complex (PB) is a functionally and anatomically complex structure involved in a range of homeostatic and sensory functions, including nociceptive transmission. (eneuro.org)
  • The antinociceptive effects of a single LVVA-SM treatment on rat nociceptive behavior during the commonly used formalin test were investigated. (hindawi.com)