Trigeminal Wide Dynamic Range Neurons Research Articles

The nitric oxide donor, isosorbide dinitrate, induces a cephalic cutaneous hypersensitivity, associated with sensitization of the medullary dorsal horn

Nitric oxide donors are known to produce headache in healthy as well as migraine subjects, and to induce extracephalic cutaneous hypersensitivity in rodents. However, little is known on the effect of nitric oxide donors on cephalic cutaneous sensitivity. Combining behavioral, immunohistochemical, and in vivo electrophysiological approaches, this study investigated the effect of systemic administration of the nitric oxide donor, isosorbide dinitrate (ISDN), on cephalic and extracephalic cutaneous sensitivity and on neuronal activation within the medullary dorsal horn (MDH) in the rat. Systemic administration of ISDN increased selectively the first phase and interphase of the facial formalin test, but had no effect on the hindpaw formalin one. Monitoring neuronal activity within the MDH with phospho-ERK1/2 immunoreactivity revealed that ISDN alone did not activate MDH neurons, but significantly increased the number of formalin-evoked phospho-ERK1/2-immunoreactive cells in the ipsilateral, but not contralateral, MDH. Using in vivo electrophysiological unit recordings, we show that ISDN administration never affected the spontaneous activity of trigeminal wide dynamic range neurons, but, facilitated C-fiber-evoked responses in half the neurons tested. This research demonstrates that a nitric oxide donor, isosorbide dinitrate, induces selectively cephalic hyperalgesia that arises as a consequence of central sensitization in pain pathways that subserve meningeal nociception. This model better mimics the clinical condition and offers another possibility of studying the role of nitric oxide donor in the physiopathology of headache.

Ongoing activity in trigeminal wide-dynamic range neurons is driven from the periphery

Ongoing activity of spinal trigeminal neurons is observed under various conditions and suggested to be responsible for ongoing headache. It can be spontaneous, i.e. arising intrinsically from the neuron, or the product of descending influences from other central neurons, or maintained by ongoing afferent input. The aim of the present study was to examine if ongoing activity of neurons in different subnuclei of the spinal trigeminal nucleus is driven from peripheral afferent input. Experiments were performed in Wistar rats anesthetized with isoflurane or Nembutal/urethane. Ongoing activity of single wide-dynamic range (WDR) neurons was recorded with carbon fiber glass microelectrodes in two subnuclei of the spinal trigeminal nucleus: oral (Sp5O) and caudal (Sp5C). Peripheral receptive fields were evaluated using von Frey filaments. Sp5O neurons received peripheral input from facial areas innervated by the mandibular branch of the trigeminal nerve. Units in Sp5C had receptive fields in the surgically exposed dura mater and in facial areas innervated by the ophthalmic and maxillary branch of the trigeminal nerve. Saline or the local anesthetic lidocaine was locally applied onto the exposed dura mater or microinjected into V3 (for Sp5O units) or V1/V2 (for Sp5C units) divisions of the trigeminal ganglion via the infraorbital channel. Local application of lidocaine onto the exposed dura caused mechanical insensitivity of dural receptive fields but not significant decrease in ongoing activity. Microinjection of lidocaine but not saline into the trigeminal ganglion was followed by a substantial decrease in both the receptive field size and the activity of the recorded WDR units. Mechanical insensitivity of receptive fields after trigeminal ganglion blockade was accompanied by the disappearance of ongoing activity. We conclude that the ongoing activity of WDR neurons in the spinal trigeminal nucleus, which may be indicative for processes of sensitization, is driven remotely by ongoing afferent input.

Cortical and brainstem LTP-like plasticity in Huntington's disease

Recent studies have reported abnormalities in short-term plasticity in patients with Huntington's disease (HD). However, is not known whether long-term potentiation (LTP)-like plasticity is also affected in these patients. We tested cortical and brainstem LTP-like plasticity in eight symptomatic HD patients and in 10 healthy age-matched controls. To probe motor cortex LTP-like plasticity we used paired associative stimulation (PAS), a technique that combines repetitive electric stimulation of the median nerve with subsequent transcranial magnetic stimulation (TMS) of the contralateral motor cortex at 25 ms. To investigate brainstem plasticity, we induced LTP-like phenomena in the trigeminal wide dynamic range neurons (WDR) of the blink reflex circuit by pairing an high-frequency train of electrical stimuli (HFS) over the right supraorbital nerve (SO) coincident with the R2 response elicited by a preceding SO stimulus. Our results demonstrate impairment of both cortical and brainstem LTP-like plasticity in symptomatic HD patients which is similar to LTP deficits previously reported in HD animal models. These findings might well represent the neurophysiological correlates of memory deficits often present in HD.

Impaired long‐term potentiation–like plasticity of the trigeminal blink reflex circuit in Parkinson's disease

We investigated the hypothesis that Parkinsons's disease (PD) is associated with abnormal plasticity of the neuronal circuits mediating blink reflex. We induced long-term potentiation (LTP)-like plasticity in trigeminal wide dynamic range neurons of the blink reflex circuit by pairing an high-frequency train of electrical stimuli over the right supraorbital nerve (SO) coincident with the R2 response elicited by a preceding SO stimulus. The facilitation of the R2 response after the induction protocol was markedly decreased in patients relative to controls. Treatment with dopaminergic drugs normalized the LTP-like plasticity of the R2 response. We conclude that nigrostriatal denervation disrupts LTP-like plasticity in the trigeminal reflex circuit.

Enhanced Long-Term Potentiation-Like Plasticity of the Trigeminal Blink Reflex Circuit in Blepharospasm

Benign essential blepharospasm (BEB) is a focal cranial dystonia affecting eye closure. Here, we tested the hypothesis that BEB is associated with abnormal plasticity of the neuronal circuits mediating reflex blinks. In patients with BEB and healthy age-matched controls, we used the conditioning protocol introduced by Mao and Evinger (2001) to induce long-term potentiation (LTP)-like plasticity in trigeminal wide dynamic range neurons of the blink reflex circuit. High-frequency trains of electrical stimuli were repeatedly given over the right supraorbital nerve (SO) and timed to coincide with the R2 response elicited by a preceding SO stimulus. High-frequency stimulation (HFS) resulted in a long-lasting and input-specific potentiation of the R2 response in both groups, yet the facilitation of the R2 response was markedly increased in patients relative to controls. Botulinum toxin (BTX) injections in both orbicularis oculi muscles normalized the previously enhanced LTP-like plasticity of the R2 response. The increased responsiveness to HFS provides first-time evidence that LTP-like plasticity is increased in the trigeminal reflex circuit of patients affected by BEB. The results also show that the enhanced modifiability is not fixed in BEB, because BTX injections can transiently restore normal LTP-like plasticity. We propose that an abnormal corneal input induced by excessive blinking exacerbates increased LTP-like plasticity in BEB. BTX treatment removes the latter and restores plasticity toward normal values. Our results support the concept that maladaptive reorganization contributes to the pathophysiology of focal dystonias.

Differential distribution of four types of tooth pulp neurons in the caudal medulla oblongata of the cat

The medulla oblongata caudal to the obex was explored for neurons responsive to tooth pulp (TP) stimulation in cats. Four different classes of TP neurons were found. They were TP specific neurons, trigeminal wide dynamic range neurons with TP input, trigeminal subnucleus reticularis ventralis (SRV) neurons with TP input and convergent reticular formation neurons with TP input. They were differentially distributed within the caudal medulla oblongata.

1921 The functional properties of tooth pulp neurons in the caudal medulla oblongata of the cat

The medulla oblongata caudal to the obex was explored for neurons responsive to tooth pulp (TP) stimulation in cats. Four different classes of TP neurons were found. They were TP specific neurons, trigeminal wide dynamic range neurons with TP input, trigeminal subnucleus reticularis ventralis (SRV) neurons with TP input and convergent reticular formation neurons with TP input. They were differentially distributed within the caudal medulla oblongata.

Location and functional organization of trigeminal wide dynamic range neurons within the nucleus ventralis posteromedialis of the cat : Neurosci. Lett., 39 (1983) 231–236

Location and functional organization of trigeminal wide dynamic range neurons within the nucleus ventralis posteromedialis of the cat : Neurosci. Lett., 39 (1983) 231–236

Location and functional organization of trigeminal wide dynamic range neurons within the nucleus ventralis posteromedials of the cat

In urethane-chloralose-anesthetized cats, trigeminal wide dynamic range (WDR) neurons were explored in the posterior thalamus. They were found within a narrow zone (about 300 μm wide) of the shell region of the nucleus ventralis posteromedialis (VPM), just rostral to the region where trigeminal nociceptive specific (NS) neurons were located. This narrow zone was somatotopically organized with respect to the center of the receptive field. The mandibular division was represented ventromedially, the ophthalamic division were represented dorsolaterally, and the maxillary division fell in between. Neither NS nor WDR trigeminal units were found within the medial part of the posterior complex of the thalamus (POm).

Functional relationships between neurons of marginal and substantia gelatinosa layers of primate dorsal horn

ArticlesFunctional relationships between neurons of marginal and substantia gelatinosa layers of primate dorsal hornD. D. Price, H. Hayashi, R. Dubner, and M. A. RudaD. D. Price, H. Hayashi, R. Dubner, and M. A. RudaPublished Online:01 Nov 1979https://doi.org/10.1152/jn.1979.42.6.1590MoreSectionsPDF (4 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited BySpinal Circuits Transmitting Mechanical Pain and Itch8 May 2017 | Neuroscience Bulletin, Vol. 34, No. 1Spinal dorsal horn neurone targets for nociceptive primary afferents: do single neurone morphological characteristics suggest how nociceptive information is processed at the spinal levelBrain Research Reviews, Vol. 46, No. 2Correlation of functional activation in the rat spinal cord with neuronal activation detected by immunohistochemistryNeuroImage, Vol. 22, No. 4Neurons involved in the exteroceptive function of painPain, Vol. 106, No. 3Exogenous Tumor Necrosis Factor-α Induces Abnormal Discharges in Rat Dorsal Horn NeuronsSpine, Vol. 27, No. 15C Fiber Responses of Wide Dynamic Range Neurons in the Spinal Dorsal HornClinical Orthopaedics and Related Research, Vol. 349Encoding of Corneal Input in Two Distinct Regions of the Spinal Trigeminal Nucleus in the Rat: Cutaneous Receptive Field Properties, Responses to Thermal and Chemical Stimulation, Modulation by Diffuse Noxious Inhibitory Controls, and Projections to the Parabrachial AreaI. D. Meng, J. W. Hu, A. P. Benetti, and D. A. Bereiter1 January 1997 | Journal of Neurophysiology, Vol. 77, No. 1Sensitization of high mechanothreshold superficial dorsal horn and flexor motor neurones following chemosensitive primary afferent activationPain, Vol. 58, No. 2Short-term plasticity in turtle dorsal horn neurons mediated by L-type Ca2+ channelsNeuroscience, Vol. 61, No. 2Neurons in the superficial dorsal horn of the rat spinal cord projecting to the medullary ventrolateral reticular formation express c-fos after noxious stimulation of the skinBrain Research, Vol. 623, No. 2Emerging relationships between cytochemical properties and sensory modality transmission in primary sensory neuronsBrain Research Bulletin, Vol. 30, No. 3-4Reply to F. CerveroPain, Vol. 51, No. 2Intrathecal MK-801 and local nerve anesthesia synergistically reduce nociceptive behaviors in rats with experimental peripheral mononeuropathyBrain Research, Vol. 576, No. 2Microinjections of norepinephrine within the superficial laminae of trigeminal subnucleus caudalis evoke increases in plasma adrenocorticotropin in the ratBrain Research, Vol. 568, No. 1-2The spino-latero-reticular system of the rat: Projections from the superficial dorsal horn and structural characterization of marginal neurons involvedNeuroscience, Vol. 45, No. 1Evidence that substance P selectively modulates C-fiber-evoked discharges of dorsal horn nociceptive neuronsBrain Research, Vol. 526, No. 2Electrical stimulation reveals relatively ineffective sural nerve projections to dorsal horn neurons in the catBrain Research, Vol. 371, No. 1Selective reduction of second pain sensations by systemic morphine in humansPain, Vol. 24, No. 1A psychophysical analysis of morphine analgesiaPain, Vol. 22, No. 3Ultrastructural study of neurotensin immunoreactivity in the superficial laminae of the dorsal horn of the ratPeptides, Vol. 5, No. 6Receptive fields and responses to ionophoretically applied nonradrenaline and 5-hydroxytryptamine of units recorded in laminae I–III of cat dorsal hornBrain Research, Vol. 288, No. 1-2Basic neurobiologic mechanisms of pain and analgesiaThe American Journal of Medicine, Vol. 75, No. 5Responses of substantia gelatinosa neurons to putative neurotransmitters in an in vitro preparation of the adult rat spinal cordBrain Research, Vol. 279, No. 1-2Location and functional organization of trigeminal wide dynamic range neurons within the nucleus ventralis posteromedials of the catNeuroscience Letters, Vol. 39, No. 3Somatotopic distribution of trigeminal nociceptive specific neurons within the caudal somatosensory thalamus of catNeuroscience Letters, Vol. 39, No. 2Influences of contralateral nerve and skin stimulation on neurones in the substantia gelatinosa of the rat spinal cordNeuroscience Letters, Vol. 36, No. 2Chronic peripheral nerve section diminishes the primary afferent A-fibre mediated inhibition of rat dorsal horn neuronesBrain Research, Vol. 242, No. 1The cytoarchitecture of gabaergic neurons in rat spinal cordBrain Research, Vol. 238, No. 2The responses of neurones of the superficial dorsal horn to ionophoretically applied glutamate ionBrain Research, Vol. 231, No. 2Intrathecal substance P and somatostatin in rats: Behaviors indicative of sensationPeptides, Vol. 3, No. 1A Study of the cutaneous afferent input to substantia gelatinosaNeuroscience, Vol. 6, No. 11An immunohistochemical study of neuronal populations containing neuropeptides or γ-aminobutyrate within the superficial layers of the rat dorsal hornNeuroscience, Vol. 6, No. 10Spinal cord layer I neurons with axon collaterals that generate local arborsBrain Research, Vol. 209, No. 2Descending influences on receptive fields and activity of single units recorded in laminae 1, 2 and 3 of cat spinal cordBrain Research, Vol. 199, No. 2Raphe and periaqueductal gray induced suppression of non-nociceptive neuronal responses in the dorsal column nuclei and trigeminal sub-nucleus caudalisBrain Research, Vol. 200, No. 1The substantia gelatinesa. A gate control mechanism set across a sensory pathwayTrends in Neurosciences, Vol. 3, No. 9 More from this issue > Volume 42Issue 6November 1979Pages 1590-1608 Copyright & PermissionsCopyright © 1979 the American Physiological Societyhttps://doi.org/10.1152/jn.1979.42.6.1590PubMed228014History Published online 1 November 1979 Published in print 1 November 1979 Metrics