Primary Sensory Projection Research Articles

Alloknesis refers to itch caused by normally non itch-inducing stimuli, particularly light mechanical stimuli, such as contacts with clothes or other human bodies. This symptom occurs in patients suffering from chronic itch. While it has been mainly described in patients with atopic dermatitis, it is probably present in numerous other conditions and it could induce a severe burden. Until now, it is mainly diagnosed using Von Frey filaments and validated questionnaires are lacking. Alloknesis differs from mechanical pruritus in that it is linked to sensitization to pruritus and therefore occurs in pathological conditions, whereas mechanical pruritus (triggered by the presence of insects on the skin, for example) is a physiological phenomenon. While the role of central sensitization to pruritus in alloknesis is still poorly understood, the role of peripheral sensitization is becoming clearer. Interactions between low-threshold mechanoreceptors (LTMRs) and spinal interneurons are especially involved. Both the mechanical labelled pathway and the polymodal pathway have been shown to contribute to mechanical alloknesis. The mechanical labelled pathway comprises dedicated primary sensory neurons, spinal interneurons, and projection neurons that are functionally distinct from those involved in chemical itch. The polymodal pathway relies on a subset of primary sensory neurons traditionally associated with chemical itch, which can also transduce light mechanical stimuli through the activation of the mechanosensitive ion channel PIEZO1. Both converge onto the gastrin-releasing peptide (GRP) - GRP receptor (GRPR) chemical itch pathway in the spinal cord. Alloknesis is largely unknown to healthcare professionals and even more so to patients, and is not actively investigated. The objective of reducing alloknesis should be considered a therapeutic goal. To date, it has not been investigated in clinical trials. A novel research domain is emerging concerning this symptom, which exerts a substantial impact on the daily lives of numerous patients.

Hearing depends on extracting frequency, intensity, and temporal properties from sound to generate an auditory map for acoustical signal processing. How physiology intersects with molecular specification to fine tune the developing properties of the auditory system that enable these aspects remains unclear. We made a novel conditional deletion model that eliminates the transcription factor NEUROD1 exclusively in the ear. These mice (both sexes) develop a truncated frequency range with no neuroanatomically recognizable mapping of spiral ganglion neurons onto distinct locations in the cochlea nor a cochleotopic map presenting topographically discrete projections to the cochlear nuclei. The disorganized primary cochleotopic map alters tuning properties of the inferior colliculus units, which display abnormal frequency, intensity, and temporal sound coding. At the behavioral level, animals show alterations in the acoustic startle response, consistent with altered neuroanatomical and physiological properties. We demonstrate that absence of the primary afferent topology during embryonic development leads to dysfunctional tonotopy of the auditory system. Such effects have never been investigated in other sensory systems because of the lack of comparable single gene mutation models.SIGNIFICANCE STATEMENT All sensory systems form a topographical map of neuronal projections from peripheral sensory organs to the brain. Neuronal projections in the auditory pathway are cochleotopically organized, providing a tonotopic map of sound frequencies. Primary sensory maps typically arise by molecular cues, requiring physiological refinements. Past work has demonstrated physiologic plasticity in many senses without ever molecularly undoing the specific mapping of an entire primary sensory projection. We genetically manipulated primary auditory neurons to generate a scrambled cochleotopic projection. Eliminating tonotopic representation to auditory nuclei demonstrates the inability of physiological processes to restore a tonotopic presentation of sound in the midbrain. Our data provide the first insights into the limits of physiology-mediated brainstem plasticity during the development of the auditory system.

Teleostean trigeminal nerve somatosensory fibers consists of maxillar, ophthalmic, and mandibular branches. Nevertheless, it is still unclear about the central distribution of the trigeminal nerves. The projections of primary sensory trigeminal nerves were tested by the method of tract-tracing in the carp (Cyprinus carpio). Tracer was injected into trigeminal nerves’ root marked terminals in the tautomeral principal sensory trigeminal nucleus, medial funicular nucleus, descending trigeminal nucleus, medial part of posterior lateral valvular nucleus and facial lobe. The study revealed that the primary trigeminal sensory projection patterns of a cyprinid teleost, the carp are similar to those of other vertebrates such as mammals, birds, reptiles and amphibians. The results of our research also suggested that the presence of an organizational plan was common to vertebrates .

Analysis of the unmyelinated primary sensory neurone projection through the dorsal columns of the rat spinal cord using transganglionic transport of the plant lectin Bandeiraea simplicifolia I-isolectin B 4

The postnatal development of the primary sensory afferent projection to the thoracic (T4) and lumbar (L4) spinal cord of the marsupial species Monodelphis domestica was studied by using anterograde and retrograde neuronal tracers. Large numbers of primary afferents and motoneurons were labelled by application of the carbocyanine dye DiI into individual dorsal root ganglia (DRG) afferents in short-term organ cultures. Dorsal root axons had entered the cord at birth, but most primary afferent innervation of the grey matter and the establishment of cytoarchitectural lamination occurs postnatally. In addition to ipsilateral projections, some primary afferents that projected to the dorsal horn extended across the midline into the equivalent contralateral regions of the grey matter. Similarly, motoneuron dendrites occasionally extended across midline and into the contralateral grey matter. The first fibres innervating the spinal cord project to the ventral horn and formed increasingly complex terminal arbours in the motor columns between P1 and P7. After P5 many afferents were seen projecting to the dorsal horn, with the superficial dorsal horn being the last region of the spinal grey to be innervated. Histochemical labelling with the lectin Griffonia simplicifolia indicated that C fibre primary afferents had arborised in the superficial dorsal horn by P14. The sequence of primary afferent innervation is thus similar to that described in the rat, but this sequence occurs over a period of several weeks in Monodelphis, compared with several days in the rat.

Event-related potentials were measured in 12 healthy youth subjects aged 19-22 using the paradigm "cross-modal and delayed response" which is able to improve unattended purity and to avoid the effect of task target on the deviant components of ERP. The experiment included two conditions: (i) Attend visual modality, ignore auditory modality; (ii) attend auditory modality, ignore visual modality. The stimuli under the two conditions were the same. The difference wave was obtained by subtracting ERPs of the standard stimuli from that of the deviant stimuli. The present results showed that mismatch negativity (MMN), N2b and P3 components can be produced in the auditory and visual modalities under attention condition. However, only MMN was observed in the two modalities under inattention condition. Auditory and visual MMN have some features in common: their largest MMN wave peaks were distributed respectively over their primary sensory projection areas of the scalp under attention condition, but over fronto-central scalp under inattention condition. There was no significant difference between the amplitudes of visual and auditory MMN. Their amplitudes and the scalp distribution were unaffected by attention, thus suggesting that MMN amplitude is an important index reflecting automatic processing in the brain. However, the latency of the auditory and visual MMN were affected by attention, showing that MMN not only reflects automatic processing but also probably relates to control processing.

Spatial organization and plasticity of the primary and secondary olfactory projections in goldfish

The time course of the microglial cell reaction in central nervous system primary sensory projection territories has been examined following peripheral nerve injury in the adult rat using qualitative and quantitative analysis of immunoreactivity with the monoclonal antibody OX-42, which recognises the complement receptor CR3. The regions examined included the gracile nucleus, the column of Clarke and the spinal cord dorsal horn (superficial and deep laminae separately) after unilateral sciatic nerve transection, and the spinal trigeminal nucleus following unilateral infraorbital nerve transection. In all territories examined a qualitative increase in OX-42 immunoreactivity was observed 24 h postlesion. Further, quantitative analysis revealed an exponential development of the OX-42 immunoreactivity, with a peak at one week postlesion, thereafter showing a slow exponential decline. Our results show that the signal (or signals) that induces the microglial cell response in primary sensory projection territories is rapid in comparison to previously described central degenerative changes following peripheral nerve lesions (transganglionic degeneration). These findings are compatible with the hypothesis that activated microglia play a pathogenetic role in the development of transganglionic degeneration.

In 1972 when we began to analyze the vast amount of material from the laboratories of physiological psychologists, we had only a vague conceptualization of what a model of attention might look like. We began where everyone else had, with the view that everything had something to do with "arousal" but with Lacey's (1967) warning in mind that all of the dependent variables might not actually be measuring aspects of the same process. With this warning in mind, we were forced by the data to organize them into a three-systems mode. Since the first publication of this model in 1975, we have found increasing amounts of evidence to support and extend it. This evidence is briefly reviewed in the present paper in terms of the techniques employed in various types of investigation. Further, the current review of data has made it possible to specify the para-attentional substrate (the extrinsic lemniscal primary projection systems) upon which the three systems described in the earlier model operate. The earlier model was based on psychophysiological, neurobehavioral and neurochemical analyses while the current specification results from the results of recordings of event-related brain electrical responses. The conclusions derived from these results can be summarized as follows: First. It has become possible to distinguish controlled attention from the para-attentional pre- and post-attentive automatic processes upon which controls operate. Second. The pre- and post-attentive processes appear to be coordinate with activity in the extrinsic lemniscal primary sensory projection systems. Processing in these systems is reflected in the early components of event-related brain electrical potentials. These extrinsic systems are, however, not just throughputs for further processing. Rather, they are sensitive to the history of reinforcement which the subject has experienced. The concept of a limited channel capacity must, therefore, be modified to encompass this ability of organisms to improve, through practice, their competence to process a great deal of information in parallel. Competence, not capacity, limits central processing span. Third. A set of intrinsic extralemniscal processing systems has been identified to operate via a tecto-tegmental pathway to the reticular nucleus of the thalamus. The later components (N2P3, etc.) of event-related potentials have been shown to reflect processing in these systems and those that control them. Activity in these systems has been related to targeted conscious awareness.(ABSTRACT TRUNCATED AT 400 WORDS)

The brain of young domestic chicks was investigated using a Timm sulfide silver method. Serial Vibratome sections were analyzed under the light microscope, and the localization of zinc-positive structures in selected areas was determined at the ultrastructural level. Both strong and differential staining was visible in the avian telencephalon whereas most subtelencephalic structures showed a pale reaction. The highest staining intensity was found in the nonprimary sensory regions of the telencephalon such as the hyperstriatum dorsale, hyperstriatum ventrale, hippocampus, palaeostriatum augmentatum, lobus parolfactorius and caudal parts of neostriatum. There was an overall gradient of staining intensity in neostriatal areas from rostral to caudal with the heaviest zinc deposits in the caudal neostriatum. Primary sensory projection areas, such as the ectostriatum (visual), hyperstriatum intercalatum superius (visual), nucleus basalis (beak representation), the input layer L2 of the auditory field L and the somatosensory area rostral to field L were selectively left unstained. Fiber tracts throughout the brain were free of zinc deposits except for glial cells. In electron micrographs of stained regions, silver grains were localized in some presynaptic boutons of asymmetric synpases (Gray type I), within the cytoplasm of neuronal somata and sporadically in the nucleus. The possible involvement of zinc in synaptic transmission and other processes is discussed.

Transganglionic transport of horseradish peroxidase was used to study the potential for collateral sprouting of saphenous nerve afferent fibers in the lumbar dorsal horn of the adult rat following (1) combined unilateral saphenous nerve crush and ipsilateral sciatic nerve resection, (2) unilateral saphenous nerve crush, and (3) unilateral sciatic nerve resection. The saphenous nerve on the nonlesioned contralateral side served as control. Eight weeks after the lesion(s) the animals were subjected to bilateral application of horseradish peroxidase to the saphenous nerves. The distribution of the ensuing labeling in the superficial dorsal horn was subsequently mapped. Combined saphenous nerve crush and sciatic nerve resection resulted in expansion of the saphenous nerve projection area in the dorsal horn when compared to the nonlesioned control side (mean = 13%, P less than 0.05). No expansion of the saphenous nerve projection was found following isolated saphenous nerve crush or sciatic nerve resection, respectively (P greater than 0.05). The findings indicate that in the adult rat, central processes of primary sensory neurons which are regenerating their peripheral processes can extend collateral sprouts into adjacent projection areas in the superficial dorsal horn subjected to previous deafferentation by peripheral nerve resection.

1. Responses suggesting activation of the vestibular system, elicited by electrical stimulation of the human thalamus during 22 routine stereotaxic neurosurgical procedures, were examined in a retrospective study to determine the possible existence of vestibulothalamo-cortical projections in man. 2. Such responses were most frequently described as sensations of movement through space and were associated with two distinct vestibulothalamic projections: a) an anterior relay was situated ventral to the medial lemniscus, passing lateral to the red nucleus and dorsal to the subthalamic nucleus prior to terminating in the nucleus ventrointermedius (Vim) (comparable to VPLo in primates); b) a posterior relay associated with the auditory pathway (lateral lemniscus and brachium of the inferior colliculus) projected to the medial geniculate body. 3. The production of sensations of motion in conscious patients by stimulating areas that are similar to those reported constituting vestibulothalamic pathways in cats and primates implies a distinct primary sensory cortical projection for processing information from the vestibular receptors pertaining to the recognition of spatial movements.

Unimodal and multimodal response properties of neurons in the cat's superior colliculus

Abstract Expabsion of the coronal gyrus in Lutra and Pteroneura indicates a somatic sensory specialization of the head region, presumably in the form of extremely sensitive vibrissae. Enlargement of the primary somatic sensory projection area of the forelimb in Amblonyx, Aonyx, Parainyx and, in a different way, in Enhydra, correlates with anatomical and behavioral observations indicating increased tactile sensitivity of the hand of those otters. Fossil endocranial casts reveal that such specializations, at least in the Lutra and Aonyx groupe, were developed as far back as about ten million years ago. Potamotheirium, representing an independent line of aquatic mustelids, had an enlarged coronal gyrus 25 million years ago, at a time when in other respects it; brain was still quite primitive; descendants of Potamotherium survived until ten million years ago in North America.

Changes in visual recovery functions produced by temporal lobe stimulation in monkeys

The equivalence of recruiting and augmenting phenomena in the visual cortex of the cat

A note on the characteristic response pattern in primary sensory projection cortex of the cat following a synchronous afferent volley

Responses from an association area secondarily activated from optic cortex.

ArticlesRESPONSES OF CORTEX TO DIRECT ELECTRICAL STIMULI APPLIED AT DIFFERENT DEPTHSGeorge H. Bishop, and Margaret H. ClareGeorge H. Bishop, and Margaret H. ClarePublished Online:01 Jan 1953https://doi.org/10.1152/jn.1953.16.1.1MoreSectionsPDF (4 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Back to Top Next Download PDF FiguresReferencesRelatedInformationCited ByEarly Potentials of Direct Cortical Responses: Experimental Study in Dogs and Pathophysiological and Clinical ImplicationsNeurosurgery, Vol. 43, No. 2Functional development of the neonatal rat retinotectal pathwayDevelopmental Brain Research, Vol. 72, No. 2A method for eliminating the stimulus artifact from digital recordings of the direct cortical responseComputers and Biomedical Research, Vol. 24, No. 2Current source-density and neuromagnetic analysis of the direct cortical response in rat cortexBrain Research, Vol. 450, No. 1-2Motor and somatosensory evoked potentials recorded from the ratElectroencephalography and Clinical Neurophysiology, Vol. 69, No. 1Magnetic field influence on central nervous system functionExperimental Neurology, Vol. 95, No. 3Nonlinearity in the generation of antidromic activity during evoked cortical activityExperimental Neurology, Vol. 71, No. 2Visual evoked potential in man: Early oscillatory potentialsElectroencephalography and Clinical Neurophysiology, Vol. 45, No. 6Visual evoked response and behavioral correlates of plasma methadone concentrations in catsPharmacology Biochemistry and Behavior, Vol. 7, No. 2Influence of association cortex on penicillin discharges in the primary visual cortexElectroencephalography and Clinical Neurophysiology, Vol. 41, No. 6The effects of varying doses of Δ9-tetrahydrocannabinol on the human visual and somatosensory evoked responseElectroencephalography and Clinical Neurophysiology, Vol. 35, No. 4Visually evoked responses in the rat, guinea pig, cat, monkey, and manExperimental Neurology, Vol. 40, No. 2Influence of staphylococcal alpha-hemolysin on cortical sensory evoked potentialsToxicology and Applied Pharmacology, Vol. 25, No. 1Multiple use of the auditory cortex: Interaction at a single pointExperimental Neurology, Vol. 34, No. 1The influence of hypnotics and tranquillizers on some evoked cortical potentialsNeuropharmacology, Vol. 10, No. 1The cortex as interferometer: The transmission of amplitude, frequency and phase in cortical structuresNeuropsychologia, Vol. 7, No. 2Fast-fiber system of rabbit optic nerveVision Research, Vol. 8, No. 11The flash-evoked afterdischargeBrain Research, Vol. 9, No. 2Centrifugal control of the olfactory bulb as revealed by induced DC potential changesBrain Research, Vol. 6, No. 3On the nature of the primary evoked responseExperimental Neurology, Vol. 15, No. 1The onset mechanism of the epileptiform afterdischarge at neocortical levelExperimental Neurology, Vol. 13, No. 2Laminar stimulation for direct cortical responses from intact and chronically isolated cortexElectroencephalography and Clinical Neurophysiology, Vol. 17, No. 4Modulation of cortical activity by the lateral geniculate bodyElectroencephalography and Clinical Neurophysiology, Vol. 15, No. 5Dipoles of spontaneous activity in the cerebral cortexExperimental Neurology, Vol. 6, No. 4The production of cobalt experimental epilepsy in the ratElectroencephalography and Clinical Neurophysiology, Vol. 14, No. 3Effect of selected excitant and depressant agents on the cortical response to midline thalamic stimulation in the rabbitElectroencephalography and Clinical Neurophysiology, Vol. 13, No. 3The interactions of several varieties of evoked response in visual and association cortex of the catElectroencephalography and Clinical Neurophysiology, Vol. 13, No. 1Experimental modification of dendritic and recruiting processes and their DC after-effectsElectroencephalography and Clinical Neurophysiology, Vol. 10, No. 4Singly and repetitively evoked potentials in human cerebral cortex with D.C. changesElectroencephalography and Clinical Neurophysiology, Vol. 10, No. 2Potential wave mechanisms in cat cortexElectroencephalography and Clinical Neurophysiology, Vol. 8, No. 4An analysis of the cortical response to antidromic pyramidal tract stimulation in the catElectroencephalography and Clinical Neurophysiology, Vol. 8, No. 3A note on the characteristic response pattern in primary sensory projection cortex of the cat following a synchronous afferent volleyElectroencephalography and Clinical Neurophysiology, Vol. 8, No. 3Properties of dendrites; apical dendrites of the cat cortexElectroencephalography and Clinical Neurophysiology, Vol. 7, No. 1Correlation between steady transcortical potential and evoked responseElectroencephalography and Clinical Neurophysiology, Vol. 6 More from this issue > Volume 16Issue 1January 1953Pages 1-19 https://doi.org/10.1152/jn.1953.16.1.1PubMed13035464History Published online 1 January 1953 Published in print 1 January 1953 Metrics

OBSERVATIONS ON CORTICAL SOMATIC SENSORY MECHANISMS OF CAT AND MONKEY