scholarly journals Response Properties of Whisker-Related Neurons in Rat Second Somatosensory Cortex

2004 ◽  
Vol 92 (4) ◽  
pp. 2083-2092 ◽  
Author(s):  
Ernest E. Kwegyir-Afful ◽  
Asaf Keller
Keyword(s):  
Somatosensory Cortex ◽  
Receptive Fields ◽  
Stimulus Onset ◽  
Similar Response ◽  
Activity Levels ◽  
Response Latencies ◽  
Response Properties ◽  
Fast Spiking ◽  
Evoked Activity ◽  
Lemniscal System

In addition to a primary somatosensory cortex (SI), the cerebral cortex of all mammals contains a second somatosensory area (SII); however, the functions of SII are largely unknown. Our aim was to explore the functions of SII by comparing response properties of whisker-related neurons in this area with their counterparts in the SI. We obtained extracellular unit recordings from narcotized rats, in response to whisker deflections evoked by a piezoelectric device, and compared response properties of SI barrel (layer IV) neurons with those of SII (layers II to VI) neurons. Neurons in both cortical areas have similar response latencies and spontaneous activity levels. However, SI and SII neurons differ in several significant properties. The receptive fields of SII neurons are at least five times as large as those of barrel neurons, and they respond equally strongly to several principal whiskers. The response magnitude of SII neurons is significantly smaller than that of neurons in SI, and SII neurons are more selective for the angle of whisker deflection. Furthermore, whereas in SI fast-spiking (inhibitory) and regular-spiking (excitatory) units have different spontaneous and evoked activity levels and differ in their responses to stimulus onset and offset, SII neurons do not show significant differences in these properties. The response properties of SII neurons suggest that they are driven by thalamic inputs that are part of the paralemniscal system. Thus whisker-related inputs are processed in parallel by a lemniscal system involving SI and a paralemniscal system that processes complimentary aspects of somatosensation.

scholarly journals Development of Thalamocortical Response Transformations in the Rat Whisker-Barrel System

2008 ◽  
Vol 99 (1) ◽  
pp. 356-366 ◽  
Author(s):  
Michael Shoykhet ◽  
Daniel J. Simons
Keyword(s):  
Cortical Neurons ◽  
Time Course ◽  
Receptive Fields ◽  
Second Phase ◽  
Adult Rats ◽  
Response Latencies ◽  
Thalamic Neurons ◽  
Response Properties ◽  
Temporal Domain

Extracellular single-unit recordings were used to characterize responses of thalamic barreloid and cortical barrel neurons to controlled whisker deflections in 2, 3-, and 4-wk-old and adult rats in vivo under fentanyl analgesia. Results indicate that response properties of thalamic and cortical neurons diverge during development. Responses to deflection onsets and offsets among thalamic neurons mature in parallel, whereas among cortical neurons responses to deflection offsets become disproportionately smaller with age. Thalamic neuron receptive fields become more multiwhisker, whereas those of cortical neurons become more single-whisker. Thalamic neurons develop a higher degree of angular selectivity, whereas that of cortical neurons remains constant. In the temporal domain, response latencies decrease both in thalamic and cortical neurons, but the maturation time-course differs between the two populations. Response latencies of thalamic cells decrease primarily between 2 and 3 wk of life, whereas response latencies of cortical neurons decrease in two distinct steps—the first between 2 and 3 wk of life and the second between the fourth postnatal week and adulthood. Although the first step likely reflects similar subcortical changes, the second phase likely corresponds to developmental myelination of thalamocortical fibers. Divergent development of thalamic and cortical response properties indicates that thalamocortical circuits in the whisker-to-barrel pathway undergo protracted maturation after 2 wk of life and provides a potential substrate for experience-dependent plasticity during this time.

Response Properties and Organization of Nociceptive Neurons in Area 1 of Monkey Primary Somatosensory Cortex

2000 ◽  
Vol 84 (2) ◽  
pp. 719-729 ◽  
Author(s):  
Dan R. Kenshalo ◽  
Koichi Iwata ◽  
Maurice Sholas ◽  
David A. Thomas
Keyword(s):  
Somatosensory Cortex ◽  
Dynamic Range ◽  
Receptive Fields ◽  
Primary Somatosensory Cortex ◽  
Isolated Cells ◽  
Nociceptive Neurons ◽  
Response Properties ◽  
Stimulus Response ◽  
Noxious Mechanical Stimulation ◽  
Wdr Neurons

The organization and response properties of nociceptive neurons in area 1 of the primary somatosensory cortex (SI) of anesthetized monkeys were examined. The receptive fields of nociceptive neurons were classified as either wide-dynamic-range (WDR) neurons that were preferentially responsive to noxious mechanical stimulation, or nociceptive specific (NS) that were responsive to only noxious stimuli. The cortical locations and the responses of the two classes of neurons were compared. An examination of the neuronal stimulus-response functions obtained during noxious thermal stimulation of the glabrous skin of the foot or the hand indicated that WDR neurons exhibited significantly greater sensitivity to noxious thermal stimuli than did NS neurons. The receptive fields of WDR neurons were significantly larger than the receptive fields of NS neurons. Nociceptive SI neurons were somatotopically organized. Nociceptive neurons with receptive fields on the foot were located more medial in area 1 of SI than those with receptive fields on the hand. In the foot representation, the recording sites of nociceptive neurons were near the boundary between areas 3b and 1, whereas in the hand area, there was a tendency for them to be located more caudal in area 1. The majority of nociceptive neurons were located in the middle layers (III and IV) of area 1. The fact that nociceptive neurons were not evenly distributed across the layers of area 1 suggested that columns of nociceptive neurons probably do not exist in the somatosensory cortex. In electrode tracks where nociceptive neurons were found, approximately half of all subsequently isolated neurons were also classified as nociceptive. Low-threshold mechanoreceptive (LTM) neurons were intermingled with nociceptive neurons. Both WDR and NS neurons were found in close proximity to one another. In instances where the receptive field shifted, subsequently isolated cells were also classified as nociceptive. These data suggest that nociceptive neurons in area 1 of SI are organized in vertically orientated aggregations or clusters in layers III and IV.

scholarly journals Response Properties of Whisker-Associated Trigeminothalamic Neurons in Rat Nucleus Principalis

2003 ◽  
Vol 89 (1) ◽  
pp. 40-56 ◽  
Author(s):  
Brandon S. Minnery ◽  
Daniel J. Simons
Keyword(s):  
Receptive Fields ◽  
Stimulus Onset ◽  
Response Latencies ◽  
Primary Afferent ◽  
Medial Nucleus ◽  
Afferent Fibers ◽  
Highly Sensitive ◽  
Primary Afferent Fibers ◽  
Stimulus Features ◽  
Nucleus Principalis

Nucleus principalis (PrV) of the brain stem trigeminal complex mediates the processing and transfer of low-threshold mechanoreceptor input en route to the ventroposterior medial nucleus of the thalamus (VPM). In rats, this includes tactile information relayed from the large facial whiskers via primary afferent fibers originating in the trigeminal ganglion (NV). Here we describe the responses of antidromically identified VPM-projecting PrV neurons ( n = 72) to controlled ramp-and-hold deflections of whiskers. For comparison, we also recorded the responses of 64 NV neurons under identical experimental and stimulus conditions. Both PrV and NV neurons responded transiently to stimulus onset (on) and offset (off), and the majority of both populations also displayed sustained, or tonic, responses throughout the plateau phase of the stimulus (75% of NV cells and 93% of PrV cells). Averageon and off response magnitudes were similar between the two populations. In both NV and PrV, cells were highly sensitive to the direction of whisker deflection. Directional tuning was slightly but significantly greater in NV, suggesting that PrV neurons integrate inputs from NV cells differing in their preferred directions. Receptive fields of PrV neurons were typically dominated by a “principal” whisker (PW), whose evoked responses were on average threefold larger than those elicited by any given adjacent whisker (AW; n = 197). However, of the 65 PrV cells for which data from at least two AWs were obtained, most (89%) displayed statistically significanton responses to deflections of one or more AWs. AW response latencies were 2.7 ± 3.8 (SD) ms longer than those of their corresponding PWs, with an inner quartile latency difference of 1–4 ms (±25% of median). The range in latency differences suggests that some adjacent whisker responses arise within PrV itself, whereas others have a longer, multi-synaptic origin, possibly via the spinal trigeminal nucleus. Overall, our findings reveal that the stimulus features encoded by primary afferent neurons are reflected in the responses of VPM-projecting PrV neurons, and that significant convergence of information from multiple whiskers occurs at the first synaptic station in the whisker-to-barrel pathway.

Visual Response Properties of Neurons in the LGN of Normally Reared and Visually Deprived Macaque Monkeys

2001 ◽  
Vol 85 (5) ◽  
pp. 2111-2129 ◽  
Author(s):  
Jonathan B. Levitt ◽  
Robert A. Schumer ◽  
S. Murray Sherman ◽  
Peter D. Spear ◽  
J. Anthony Movshon
Keyword(s):  
Receptive Field ◽  
Receptive Fields ◽  
Optic Chiasm ◽  
Monocular Deprivation ◽  
Specific Cell ◽  
Visual Response ◽  
Response Latencies ◽  
Macaque Monkeys ◽  
Response Properties ◽  
Parvocellular Neurons

It is now well appreciated that parallel retino-geniculo-cortical pathways exist in the monkey as in the cat, the species in which parallel visual pathways were first and most thoroughly documented. What remains unclear is precisely how many separate pathways pass through the parvo- and magnocellular divisions of the macaque lateral geniculate nucleus (LGN), what relationships—homologous or otherwise—these pathways have to the cat's X, Y, and W pathways, and whether these are affected by visual deprivation. To address these issues of classification and trans-species comparison, we used achromatic stimuli to obtain an extensive set of quantitative measurements of receptive field properties in the parvo- and magnocellular laminae of the LGN of nine macaque monkeys: four normally reared and five monocularly deprived of vision by lid suture near the time of birth. In agreement with previous studies, we find that on average magnocellular neurons differ from parvocellular neurons by having shorter response latencies to optic chiasm stimulation, greater sensitivity to luminance contrast, and better temporal resolution. Magnocellular laminae are also distinguished by containing neurons that summate luminance over their receptive fields nonlinearly (Y cells) and whose temporal response phases decrease with increasing stimulus contrast (indicative of a contrast gain control mechanism). We found little evidence for major differences between magno- and parvocellular neurons on the basis of most spatial parameters except that at any eccentricity, the neurons with the smallest receptive field centers tended to be parvocellular. All parameters were distributed unimodally and continuously through the parvo- and magnocellular populations, giving no indications of subpopulations within each division. Monocular deprivation led to clear anatomical effects: cells in deprived-eye laminae were pale and shrunken compared with those in nondeprived eye laminae, and Cat-301 immunoreactivity in deprived laminae was essentially uniformly abolished. However, deprivation had only subtle effects on the response properties of LGN neurons. Neurons driven by the deprived eye in both magno- and parvocellular laminae had lower nonlinearity indices (i.e., summed signals across their receptive fields more linearly) and were somewhat less responsive. In magnocellular laminae driven by the deprived eye, neuronal response latencies to stimulation of the optic chiasm were slightly shorter than those in the nondeprived laminae, and receptive field surrounds were a bit stronger. No other response parameters were affected by deprivation, and there was no evidence for loss of a specific cell class as in the cat.

scholarly journals Visual Response Properties and Visuotopic Representation in the Newborn Monkey Superior Colliculus

1997 ◽  
Vol 78 (5) ◽  
pp. 2732-2741 ◽  
Author(s):  
M. T. Wallace ◽  
J. G. McHaffie ◽  
B. E. Stein
Keyword(s):  
Superior Colliculus ◽  
Ocular Dominance ◽  
Receptive Fields ◽  
Spatial Summation ◽  
Visual Space ◽  
Field Size ◽  
Visual Response ◽  
Response Latencies ◽  
Developmental Models ◽  
Response Properties

Wallace M. T., J. G. McHaffie, and B. E. Stein. Visual response properties and visuotopic representation in the newborn monkey superior colliculus. J. Neurophysiol. 78: 2732–2741, 1997. Visually responsive neurons were recorded in the superior colliculus (SC) of the newborn rhesus monkey. The receptive fields of these neurons were larger than those in the adult, but already were organized into a well-ordered map of visual space that was very much like that seen in mature animals. This included a marked expansion of the representation of the central 10° of the visual field and a systematic foveal to peripheral increase in receptive field size. Although newborn SC neurons had longer response latencies than did their adult counterparts, they responded vigorously to visual stimuli and exhibited many visual response properties that are characteristic of the adult. These included surround inhibition, within-field spatial summation, within-field spatial inhibition, binocularity, and an adult-like ocular dominance distribution. As in the adult, SC neurons in the newborn preferred a moving visual stimulus and had adult-like selectivities for stimulus speed. The developmentally advanced state of the functional circuitry of the newborn monkey SC contrasts with the comparative immaturity of neurons in its visual cortex. It also contrasts with observations on the state of maturation of the newborn SC in other developmental models (e.g., cat). The observation that extensive visual experience is not necessary for the development of many adult-like SC response properties in the monkey SC may help explain the substantial visual capabilities shown by primates soon after birth.

scholarly journals Experience-Dependent Plasticity in S1 Caused by Noncoincident Inputs

2005 ◽  
Vol 94 (3) ◽  
pp. 2239-2250 ◽  
Author(s):  
David T. Blake ◽  
Fabrizio Strata ◽  
Richard Kempter ◽  
Michael M. Merzenich
Keyword(s):  
Time Window ◽  
Cortical Excitability ◽  
Receptive Fields ◽  
Stimulus Onset ◽  
Spike Timing ◽  
Interval Length ◽  
Response Latencies ◽  
Dependent Plasticity ◽  
Cortical Implants ◽  
Somatic Sensory Cortex

Prior work has shown that coincident inputs became corepresented in somatic sensory cortex. In this study, the hypothesis that the corepresentation of digits required synchronous inputs was tested, and the daily development of two-digit receptive fields was observed with cortical implants. Two adult primates detected temporal differences in tap pairs delivered to two adjacent digits. With stimulus onset asynchronies of ≥100 ms, representations changed to include two-digit receptive fields across the first 4 wk of training. In addition, receptive fields at sites responsive to the taps enlarged more than twofold, and receptive fields at sites not responsive to the taps had no significant areal change. Further training did not increase the expression of two-digit receptive fields. Cortical responses to the taps were not dependent on the interval length. Stimuli preceding a hit, miss, false positives, and true negatives differed in the ongoing cortical rate from 50 to 100 ms after the stimulus but did not differ in the initial, principal, response to the taps. Response latencies to the emergent responses averaged 4.3 ms longer than old responses, which occurs if plasticity is cortical in origin. New response correlations developed in parallel with the new receptive fields. These data show corepresentation can be caused by presentation of stimuli across a longer time window than predicted by spike-timing–dependent plasticity and suggest that increased cortical excitability accompanies new task learning.

Auditory response properties of neurons in the putamen and globus pallidus of awake cats

2014 ◽  
Vol 111 (10) ◽  
pp. 2124-2137 ◽  
Author(s):  
Renjia Zhong ◽  
Ling Qin ◽  
Yu Sato
Keyword(s):  
Basal Ganglia ◽  
Globus Pallidus ◽  
Afferent Input ◽  
Stimulus Onset ◽  
Natural Sounds ◽  
Response Latencies ◽  
Response Properties ◽  
Response Characteristics ◽  
Auditory Response ◽  
Awake Cats

Several decades of research have provided evidence that the basal ganglia are closely involved in motor processes. Recent clinical, electrophysiological, behavioral data have revealed that the basal ganglia also receive afferent input from the auditory system, but the detailed auditory response characteristics have not yet reported. The present study aimed to reveal the acoustic response properties of neurons in parts of the basal ganglia. We recorded single-unit activities from the putamen (PU) and globus pallidus (GP) of awake cats passively listening to pure tones, click trains, and natural sounds. Our major findings were: 1) responses in both PU and GP neurons were elicited by pure-tone stimuli, whereas PU neurons had lower intensity thresholds, shorter response latencies, shorter excitatory duration, and larger response magnitudes than GP neurons. 2) Some GP neurons showed a suppressive response lasting throughout the stimulus period. 3) Both PU and GP did not follow periodically repeated click stimuli well, and most neurons only showed a phasic response at the stimulus onset and offset. 4) In response to natural sounds, PU also showed a stronger magnitude and shorter duration of excitatory response than GP. The selectivity for natural sounds was low in both nuclei. 5) Nonbiological environmental sounds more efficiently evoked responses in PU and GP than the vocalizations of conspecifics and other species. Our results provide insights into how acoustic signals are processed in the basal ganglia and revealed the distinction of PU and GP in sensory representation.

Modular distribution of neurons with slowly adapting and rapidly adapting responses in area 3b of somatosensory cortex in monkeys

1984 ◽  
Vol 51 (4) ◽  
pp. 724-744 ◽  
Author(s):  
M. Sur ◽  
J. T. Wall ◽  
J. H. Kaas
Keyword(s):  
Somatosensory Cortex ◽  
Receptive Fields ◽  
Systematic Position ◽  
Stimulus Onset ◽  
Cortical Layers ◽  
Single Digit ◽  
Macaque Monkeys ◽  
Predominant Orientation ◽  
Skin Indentation ◽  
Area 3B

Recordings from the representations of the glabrous digits in area 3b of the somatosensory cortex of owl and macaque monkeys revealed two types of neurons. Rapidly adapting (RA) neurons responded only at the onset and offset of a 1-s skin indentation. Slowly adapting (SA) neurons also responded to stimulus onset and offset but, in addition, they responded throughout the 1-s skin indentation. RA neurons were found in all cortical layers while SA neurons were found only in the middle cortical layers. In electrode penetrations perpendicular to the layers, some penetrations encountered only RA neurons (RA penetrations), while other penetrations first encountered RA neurons, then SA neurons, and finally RA neurons again (SA penetrations). When closely spaced electrode penetrations were made throughout the representation of a single digit, it was apparent that RA and SA penetrations were not randomly distributed. The distribution suggested the existence of separate clusters or bands of SA and RA neurons in the middle layers of cortex. The predominant orientation of the SA and RA regions was rostrocaudally along the lengths of the digit representations. The SA and RA bands varied in width, had no systematic position in the representation of individual digits, and often crossed from the representation of one digit to another. Because of overlapping receptive fields for neurons in adjoining bands, the SA and RA bands appeared to represent the digits separately. This would allow all skin surfaces for each digit to be subserved by both types of neurons.

Spatial response properties of acoustically responsive neurons in the superior colliculus of the ferret: a map of auditory space

1987 ◽  
Vol 57 (2) ◽  
pp. 596-624 ◽  
Author(s):  
A. J. King ◽  
M. E. Hutchings
Keyword(s):  
Superior Colliculus ◽  
Stimulus Intensity ◽  
Free Field ◽  
Receptive Fields ◽  
Stimulus Onset ◽  
Spontaneous Discharge ◽  
Auditory Neurons ◽  
Response Properties ◽  
Deep Layers ◽  
Stimulus Offset

Extracellular single-unit recordings were made from auditory neurons in the superior colliculus of ferrets anesthetized with either a neuroleptic or a combination of barbiturate with paralysis. The response properties of these neurons were studied using white-noise bursts presented under free-field conditions in an anechoic chamber. Auditory neurons were found throughout the intermediate and deep layers of the superior colliculus. All neurons were spontaneously active, the rates of discharge varying from 0.1 to 61.1 spikes X s-1. Although the spontaneous discharge interspike-interval histograms for many units approximated to exponential distributions, the histograms of 44% had clear secondary peaks, indicating more than one preferred interval, and could not be modeled by a simple process. Most neurons (50%) responded only at stimulus onset, whereas 12% exhibited sustained discharges and 38% gave onset responses followed by a period of silence or reduced activity and then a period of elevated discharge, which was not apparently related to stimulus offset. Neurons with multipeaked response patterns were concentrated in the stratum griseum profundum. The latencies from arrival of the stimulus at the ear to the onset of neural activity ranged from 6 to 49 ms and decreased with increasing stimulus intensity. Although responsive to sounds over a large region of space, most neurons had clearly defined best positions at which the strongest response was obtained. The response declined as the speaker was moved away from this position, and nearly all units had peaked response profiles. The spatial tuning varied between different neurons, but most were more sharply tuned in elevation than in azimuth. Increasing the stimulus intensity did not, in general, alter the best positions of these neurons, but usually resulted in a broadening of the receptive fields, although other units became more sharply tuned. The best positions of auditory neurons varied systematically in azimuth from 20 degrees into the ipsilateral hemifield to 130 degrees into the contralateral hemifield as the electrode was moved from the rostrolateral to the caudomedial end of the superior colliculus. The best positions shifted in elevation along a rostromedial to caudolateral axis from 60 degrees above to 50 degrees below the visuoaural plane.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Distinct patterns of activity in individual cortical neurons and local networks in primary somatosensory cortex of mice evoked by square-wave mechanical limb stimulation

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0236684
Author(s):  
Mischa V. Bandet ◽  
Bin Dong ◽  
Ian R. Winship
Keyword(s):  
Somatosensory Cortex ◽  
Cortical Neurons ◽  
Cellular Response ◽  
Cortical Excitability ◽  
Primary Somatosensory Cortex ◽  
Local Networks ◽  
Response Properties ◽  
Square Wave ◽  
Evoked Activity ◽  
Sensory Evoked

Artificial forms of mechanical limb stimulation are used within multiple fields of study to determine the level of cortical excitability and to map the trajectory of neuronal recovery from cortical damage or disease. Square-wave mechanical or electrical stimuli are often used in these studies, but a characterization of sensory-evoked response properties to square-waves with distinct fundamental frequencies but overlapping harmonics has not been performed. To distinguish between somatic stimuli, the primary somatosensory cortex must be able to represent distinct stimuli with unique patterns of activity, even if they have overlapping features. Thus, mechanical square-wave stimulation was used in conjunction with regional and cellular imaging to examine regional and cellular response properties evoked by different frequencies of stimulation. Flavoprotein autofluorescence imaging was used to map the somatosensory cortex of anaesthetized C57BL/6 mice, and in vivo two-photon Ca2+ imaging was used to define patterns of neuronal activation during mechanical square-wave stimulation of the contralateral forelimb or hindlimb at various frequencies (3, 10, 100, 200, and 300 Hz). The data revealed that neurons within the limb associated somatosensory cortex responding to various frequencies of square-wave stimuli exhibit stimulus-specific patterns of activity. Subsets of neurons were found to have sensory-evoked activity that is either primarily responsive to single stimulus frequencies or broadly responsive to multiple frequencies of limb stimulation. High frequency stimuli were shown to elicit more population activity, with a greater percentage of the population responding and greater percentage of cells with high amplitude responses. Stimulus-evoked cell-cell correlations within these neuronal networks varied as a function of frequency of stimulation, such that each stimulus elicited a distinct pattern that was more consistent across multiple trials of the same stimulus compared to trials at different frequencies of stimulation. The variation in cortical response to different square-wave stimuli can thus be represented by the population pattern of supra-threshold Ca2+ transients, the magnitude and temporal properties of the evoked activity, and the structure of the stimulus-evoked correlation between neurons.

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