scholarly journals Response Properties and Morphology of Primary Somatosensory Cortical Neurons Receiving Input from the Periodontal Afferent in Cats.

1999 ◽  
Vol 43 (3) ◽  
pp. 538-550
Author(s):  
Nobuyuki Shimizu
Keyword(s):  
Cortical Neurons ◽  
Response Properties ◽  
Periodontal Afferent

scholarly journals Sensory computations in the cuneate nucleus of macaques

2021 ◽  
Vol 118 (49) ◽  
pp. e2115772118
Author(s):  
Aneesha K. Suresh ◽  
Charles M. Greenspon ◽  
Qinpu He ◽  
Joshua M. Rosenow ◽  
Lee E. Miller ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Receptive Fields ◽  
Nerve Fibers ◽  
Cuneate Nucleus ◽  
Local Skin ◽  
Response Properties ◽  
Conventional View ◽  
Random Dot Patterns ◽  
Object Features ◽  
Spatiotemporal Response

Tactile nerve fibers fall into a few classes that can be readily distinguished based on their spatiotemporal response properties. Because nerve fibers reflect local skin deformations, they individually carry ambiguous signals about object features. In contrast, cortical neurons exhibit heterogeneous response properties that reflect computations applied to convergent input from multiple classes of afferents, which confer to them a selectivity for behaviorally relevant features of objects. The conventional view is that these complex response properties arise within the cortex itself, implying that sensory signals are not processed to any significant extent in the two intervening structures—the cuneate nucleus (CN) and the thalamus. To test this hypothesis, we recorded the responses evoked in the CN to a battery of stimuli that have been extensively used to characterize tactile coding in both the periphery and cortex, including skin indentations, vibrations, random dot patterns, and scanned edges. We found that CN responses are more similar to their cortical counterparts than they are to their inputs: CN neurons receive input from multiple classes of nerve fibers, they have spatially complex receptive fields, and they exhibit selectivity for object features. Contrary to consensus, then, the CN plays a key role in processing tactile information.

scholarly journals Pairing a visual stimulus with VTA micro-stimulation changes the response properties of posterior inferior temporal cortical neurons

2021 ◽  
Vol 21 (9) ◽  
pp. 2051
Author(s):  
Jerome Herpers ◽  
Wim Vanduffel ◽  
John Arsenault ◽  
Rufin Vogels
Keyword(s):  
Visual Stimulus ◽  
Cortical Neurons ◽  
Response Properties

scholarly journals Cortical plasticity following stripe rearing in the marsupialMonodelphis domestica: neural response properties of V1

2017 ◽  
Vol 117 (2) ◽  
pp. 566-581 ◽  
Author(s):  
James C. Dooley ◽  
Michaela S. Donaldson ◽  
Leah A. Krubitzer
Keyword(s):  
Visual System ◽  
Cortical Neurons ◽  
Functional Organization ◽  
Sensory Experience ◽  
Monodelphis Domestica ◽  
Visual Environment ◽  
Visual Response ◽  
Response Properties ◽  
Dependent Plasticity ◽  
Marsupial Species

The functional organization of the primary visual area (V1) and the importance of sensory experience in its normal development have been well documented in eutherian mammals. However, very few studies have investigated the response properties of V1 neurons in another large class of mammals, or whether sensory experience plays a role in shaping their response properties. Thus we reared opossums ( Monodelphis domestica) in normal and vertically striped cages until they reached adulthood. They were then anesthetized using urethane, and electrophysiological techniques were used to examine neuronal responses to different orientations, spatial and temporal frequencies, and contrast levels. For normal opossums, we observed responses to the temporal and spatial characteristics of the stimulus to be similar to those described in small, nocturnal, eutherian mammals such as rats and mice; neurons in V1 responded maximally to stimuli at 0.09 cycles per degree and 2.12 cycles per second. Unlike other eutherians, but similar to other marsupials investigated, only 40% of the neurons were orientation selective. In stripe-reared animals, neurons were significantly more likely to respond to vertical stimuli at a wider range of spatial frequencies, and were more sensitive to gratings at lower contrast values compared with normal animals. These results are the first to demonstrate experience-dependent plasticity in the visual system of a marsupial species. Thus the ability of cortical neurons to alter their properties based on the dynamics of the visual environment predates the emergence of eutherian mammals and was likely present in our earliest mammalian ancestors.NEW & NOTEWORTHY These results are the first description of visual response properties of the most commonly studied marsupial model organism, the short-tailed opossum ( Monodelphis domestica). Further, these results are the first to demonstrate experience-dependent plasticity in the visual system of a marsupial species. Thus the ability of cortical neurons to alter their properties based on the dynamics of the visual environment predates the emergence of eutherian mammals and was likely present in our earliest mammalian ancestors.

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.

Anesthesia Changes Frequency Tuning of Neurons in the Rat Primary Auditory Cortex

2001 ◽  
Vol 86 (2) ◽  
pp. 1062-1066 ◽  
Author(s):  
Bernhard H. Gaese ◽  
Joachim Ostwald
Keyword(s):  
Auditory Processing ◽  
Cortical Neurons ◽  
Frequency Tuning ◽  
Primary Auditory Cortex ◽  
Acoustic Stimulation ◽  
Experimental Manipulation ◽  
Central Auditory Processing ◽  
Auditory Neurons ◽  
Response Properties ◽  
Central Auditory Neurons

The vast majority of investigations on central auditory processing so far were conducted under the influence of an anesthetic agent. It remains unclear, however, to what extend even basic response properties of central auditory neurons are influenced by this experimental manipulation. We used a combination of chronic recording in unrestrained animals, computer-controlled randomized acoustic stimulation, and statistical evaluation of responses to directly compare the response characteristics of single neurons in the awake and anesthetized state. Thereby we were able to quantify the effects of pentobarbital/chloral hydrate anesthesia (Equithesin) on rat auditory cortical neurons. During Equithesin anesthesia, only a portion of central neurons were active and some of their basic response properties were changed. Only 29% of the neurons still had a frequency response area. Their tuning sharpness was increased under anesthesia. Most changes are consistent with an enhancement of inhibitory influences during Equithesin anesthesia. Thus when describing response properties of central auditory neurons, the animal's anesthetic state has to be taken into account.

Comparison of response properties of cells in the cat's visual cortex at high and low luminance levels

1985 ◽  
Vol 54 (1) ◽  
pp. 61-72 ◽  
Author(s):  
A. S. Ramoa ◽  
R. D. Freeman ◽  
A. Macy
Keyword(s):  
Receptive Field ◽  
Spatial Frequency ◽  
Cortical Neurons ◽  
Ganglion Cells ◽  
Scattered Light ◽  
Cortical Cells ◽  
Response Properties ◽  
Low Luminance ◽  
Field Organization ◽  
Receptive Field Organization

Receptive-field organization of cells in the cat's striate cortex and lateral geniculate nucleus (LGN) was investigated by using bars of light as stimuli. The aim was to determine if differences occur between conditions of high and low luminance levels. Of 72 cortical cells studied, the receptive fields of 63 were clearly different at high compared with low luminances. Units that gave on-off responses to flashed bars, for example, typically displayed on-only responses at low luminance. By far the most frequent change was that off responses were reduced or absent at low luminance levels. Of 63 cells that showed clear changes, 54 were of this type. This altered receptive-field organization appears to remain for extended periods (we have monitored the steady-state case for up to 2 h). Additional tests allow us to rule out the possible influence of overall changes in response strength and scattered light. To see if similar changes in receptive-field organization are present at the level of the LGN, we recorded from a small number of cells in the LGN (n = 10) and from an additional five afferent fibers in the cortex. In each case, there was a change in center-surround organization between high and low luminance levels similar to that previously reported for retinal ganglion cells. The excitatory responses from the surround for both on-center and off-center cells were absent at low luminance. Taken together, the results suggest that surround responses that can be elicited from ganglion cells and LGN cells make an important contribution to the receptive-field organization of cortical neurons. Changes in receptive-field organization of cortical cells are apparently not accompanied by alterations of other basic response properties. Orientation (7 cells) and spatial frequency (53 cells) selectivity remain relatively unchanged when measured at different luminances. Although optimal spatial frequency is slightly lower at low luminance levels, the low spatial frequency attenuation remains unaltered. Since receptive-field changes between high and low luminance levels suggest that a unit's classification may also vary, we examined simple and complex cell characteristics using sinusoidal gratings (65 cells). Contrary to what we had anticipated, the degree of modulation of responses was relatively independent of luminance, indicating that cell classification does not vary with stimulus luminance.

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