scholarly journals Superior colliculus modulates cortical coding of somatosensory information

2019 ◽  
Author(s):  
Saba Gharaei ◽  
Suraj Honnuraiah ◽  
Ehsan Arabzadeh ◽  
Greg J Stuart
Keyword(s):  
Superior Colliculus ◽  
Somatosensory Cortex ◽  
Sensory Processing ◽  
Excitatory Input ◽  
Input Output ◽  
Direct Pathway ◽  
Direct Projection ◽  
Somatosensory Information ◽  
Relationship Of ◽  
Low Amplitude

AbstractThe cortex sends a direct projection to the superior colliculus. What is largely unknown is whether (and if so how) the superior colliculus modulates activity in the cortex. Here, we directly investigate this issue, showing that optogenetic activation of superior colliculus changes the input-output relationship of neurons in somatosensory cortex during whisker movement, enhancing responses to low amplitude whisker deflections. While there is no direct pathway from superior colliculus to somatosensory cortex, we found that activation of superior colliculus drives spiking in the posterior medial (POm) nucleus of the thalamus via a powerful monosynaptic pathway. Furthermore, POm neurons receiving input from superior colliculus provide excitatory input to somatosensory cortex. Silencing POm abolished the capacity of superior colliculus to modulate cortical whisker responses. Our findings indicate that the superior colliculus, which plays a key role in attention, modulates sensory processing in somatosensory cortex via a powerful disynaptic pathway through the thalamus.

Auditory response properties of neurons in deep layers of cat superior colliculus

1983 ◽  
Vol 49 (3) ◽  
pp. 674-685 ◽  
Author(s):  
L. Z. Wise ◽  
D. R. Irvine
Keyword(s):  
Superior Colliculus ◽  
Free Field ◽  
Receptive Fields ◽  
Great Majority ◽  
Noise Burst ◽  
Preliminary Evidence ◽  
Excitatory Input ◽  
Response Properties ◽  
Deep Layers ◽  
Spatial Fields

1. The auditory responses of 207 single neurons in the intermediate and deep layers of the superior colliculus (SC) of barbiturate -or chloralose-anesthetized cats were recorded extracellularly. Sealed stimulating systems incorporating calibrated probe microphone assemblies were employed to present tone- and noise-burst stimuli. 2. All acoustically activated neurons responded with onset responses to noise bursts. Of those neurons also tested with tonal stimuli, approximately 30% were unresponsive over the frequency range tested (0.1-40 kHz), while the others had higher thresholds to tones than to noise. 3. Details of frequency responsiveness were obtained for 55 neurons; 21 were broadly tuned, while 34 were sharply tuned with clearly defined characteristic frequencies (CFs). All sharply tuned neurons had CFs greater than or equal to 10 kHz. 4. The majority of neurons (81%) responded with latencies in the range 8-20 ms; only 11% of neurons had latencies greater than 30 ms. 5. Binaural response properties were examined for 165 neurons. The great majority (79%) received monaural excitatory input only from the contralateral ear (EO). However, most EO cells were binaurally influenced, the contralateral response being either inhibited (EO/I; 96 of 131 units) or facilitated (EO/F; 33 of 131 units) by simultaneous ipsilateral stimulation. Small subgroups were monaurally excited by either ear (EE cells; 8%) or were unresponsive monaurally but responded strongly to binaural stimulation (OO/F cells; 7%). 6. EO/I, EO/F, and OO/F neurons showed characteristic forms of sensitivity to interaural intensity differences (IIDs). The IID functions of EO/I neurons would be expected to produce large contralateral spatial receptive fields with clearly defined medial borders, such as have been described in studies of deep SC neurons employing free-field stimuli. 7. Preliminary evidence suggests a possible topographic organization of IID sensitivity in deep SC, such that the steeply sloping portion of the function (corresponding to the medial edge of the receptive field) is shifted laterally for EO/I neurons located more caudally in the nucleus. 8. The auditory properties of deep SC neurons are compared with previous reports and implications for the organization of auditory input are considered. The binaural properties and auditory spatial fields of deep SC neurons suggest that any representation of auditory space in this structure is unlikely to be based on restricted spatial fields.

Dopamine Increases the Gain of the Input-Output Response of Rat Prefrontal Pyramidal Neurons

2008 ◽  
Vol 99 (6) ◽  
pp. 2985-2997 ◽  
Author(s):  
Kay Thurley ◽  
Walter Senn ◽  
Hans-Rudolf Lüscher
Keyword(s):  
Working Memory ◽  
Neuronal Excitability ◽  
Pyramidal Neurons ◽  
D1 Receptors ◽  
Input Output ◽  
Prefrontal Cortical ◽  
Noisy Input ◽  
Relationship Of

Dopaminergic modulation of prefrontal cortical activity is known to affect cognitive functions like working memory. Little consensus on the role of dopamine modulation has been achieved, however, in part because quantities directly relating to the neuronal substrate of working memory are difficult to measure. Here we show that dopamine increases the gain of the frequency-current relationship of layer 5 pyramidal neurons in vitro in response to noisy input currents. The gain increase could be attributed to a reduction of the slow afterhyperpolarization by dopamine. Dopamine also increases neuronal excitability by shifting the input-output functions to lower inputs. The modulation of these response properties is mainly mediated by D1 receptors. Integrate-and-fire neurons were fitted to the experimentally recorded input-output functions and recurrently connected in a model network. The gain increase induced by dopamine application facilitated and stabilized persistent activity in this network. The results support the hypothesis that catecholamines increase the neuronal gain and suggest that dopamine improves working memory via gain modulation.

Corticotectal and corticothalamic efferent projections of SIV somatosensory cortex in cat

1983 ◽  
Vol 50 (4) ◽  
pp. 896-909 ◽  
Author(s):  
B. E. Stein ◽  
R. F. Spencer ◽  
S. B. Edwards
Keyword(s):  
Superior Colliculus ◽  
Somatosensory Cortex ◽  
Species Difference ◽  
Pyramidal Cells ◽  
Thalamic Nuclei ◽  
Anterior Ectosylvian Sulcus ◽  
Ventrobasal Complex ◽  
Posterior Group ◽  
Corticothalamic Projection ◽  
Efferent Projections

Substantial corticotectal (and corticothalamic) projections from the cortex of the anterior ectosylvian sulcus (AES) were demonstrated in the cat using the axonal transport methods of autoradiography and horseradish peroxidase. The corticotectal projection arises nearly exclusively from medium-large pyramidal cells in lamina V. One of the densest projecting areas of the AES is the rostral aspect of its superior bank, where a fourth somatotopic representation (SIV) has recently been demonstrated. It terminates in the intermediate and deep laminae of the superior colliculus, where somatic cells are located. The pathway is bilateral but much heavier ipsilaterally than contralaterally. In contrast to the substantial corticotectal projection from SIV and adjacent tissue, there was no unequivocal evidence for a corticotectal projection from traditional somatosensory cortex SI-SIII. This finding, that somatosensory projections to the cat superior colliculus arise from an area outside of SI-SIII, was unexpected on the basis of what is known about visual corticotectal projections. However, it is consistent with the patterns of other cortical projections that terminate in the intermediate and deep laminae of this structure and with the absence of demonstrable corticotectal influences from SI to SIII in this animal. These data are in contrast to demonstrations by other investigators that there is a corticotectal projection from SI cortex in rodents. Apparently there is a fundamental species difference in the organization of descending somatosensory pathways. A corticothalamic projection of the AES was also observed. This descending projection appeared to form a shell of labeled cells and fibers around the ventrobasal complex, but unequivocal terminal labeling within the ventrobasal complex could not be demonstrated. Dense terminal labeling was apparent in the posterior group of thalamic nuclei (PO) where thalamocortical afferents to the AES originate.

Spatio-Temporal Subthreshold Receptive Fields in the Vibrissa Representation of Rat Primary Somatosensory Cortex

1998 ◽  
Vol 80 (6) ◽  
pp. 2882-2892 ◽  
Author(s):  
Christopher I. Moore ◽  
Sacha B. Nelson
Keyword(s):  
Receptive Field ◽  
Somatosensory Cortex ◽  
Rise Time ◽  
Cortical Plasticity ◽  
Temporal Dynamics ◽  
Receptive Fields ◽  
Excitatory Input ◽  
Primary Somatosensory Cortex ◽  
Spatio Temporal ◽  
Sensory Evoked

Moore, Christopher I. and Sacha B. Nelson. Spatio-temporal subthreshold receptive fields in the vibrissa representation of rat primary somatosensory cortex. J. Neurophysiol. 80: 2882–2892, 1998. Whole cell recordings of synaptic responses evoked by deflection of individual vibrissa were obtained from neurons within adult rat primary somatosensory cortex. To define the spatial and temporal properties of subthreshold receptive fields, the spread, amplitude, latency to onset, rise time to half peak amplitude, and the balance of excitation and inhibition of subthreshold input were quantified. The convergence of information onto single neurons was found to be extensive: inputs were consistently evoked by vibrissa one- and two-away from the vibrissa that evoked the largest response (the “primary vibrissa”). Latency to onset, rise time, and the incidence and strength of inhibitory postsynaptic potentials (IPSPs) varied as a function of position within the receptive field and the strength of evoked excitatory input. Nonprimary vibrissae evoked smaller amplitude subthreshold responses [primary vibrissa, 9.1 ± 0.84 (SE) mV, n = 14; 1-away, 5.1 ± 0.5 mV, n = 38; 2-away, 3.7 ± 0.59 mV, n = 22; 3-away, 1.3 ± 0.70 mV, n = 8] with longer latencies (primary vibrissa, 10.8 ± 0.80 ms; 1-away, 15.0 ± 1.2 ms; 2-away, 15.7 ± 2.0 ms). Rise times were significantly faster for inputs that could evoke action potential responses (suprathreshold, 4.1 ± 1.3 ms, n = 8; subthreshold, 12.4 ± 1.5 ms, n = 61). In a subset of cells, sensory evoked IPSPs were examined by deflecting vibrissa during injection of hyperpolarizing and depolarizing current. The strongest IPSPs were evoked by the primary vibrissa ( n = 5/5), but smaller IPSPs also were evoked by nonprimary vibrissae ( n = 8/13). Inhibition peaked by 10–20 ms after the onset of the fastest excitatory input to the cortex. This pattern of inhibitory activity led to a functional reversal of the center of the receptive field and to suppression of later-arriving and slower-rising nonprimary inputs. Together, these data demonstrate that subthreshold receptive fields are on average large, and the spatio-temporal dynamics of these receptive fields vary as a function of position within the receptive field and strength of excitatory input. These findings constrain models of suprathreshold receptive field generation, multivibrissa interactions, and cortical plasticity.

scholarly journals Non-canonical role for Lpar1-EGFP subplate neurons in early postnatal mouse somatosensory cortex

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Filippo Ghezzi ◽  
Andre Marques-Smith ◽  
Paul G Anastasiades ◽  
Daniel Lyngholm ◽  
Cristiana Vagnoni ◽  
...  
Keyword(s):  
Cell Death ◽  
Somatosensory Cortex ◽  
Sensory Processing ◽  
Marginal Zone ◽  
Time Window ◽  
Columnar Structure ◽  
Synaptic Connectivity ◽  
Thalamic Input ◽  
Subplate Neurons ◽  
Local Input

Subplate neurons (SPNs) are thought to play a role in nascent sensory processing in neocortex. To better understand how heterogeneity within this population relates to emergent function, we investigated the synaptic connectivity of Lpar1-EGFP SPNs through the first postnatal week in whisker somatosensory cortex (S1BF). These SPNs comprise of two morphological subtypes: fusiform SPNs with local axons, and pyramidal SPNs with axons that extend through the marginal zone. The former receive translaminar synaptic input up until the emergence of the whisker barrels; a timepoint coincident with significant cell death. In contrast, pyramidal SPNs receive local input from the subplate at early ages but then – during the later time window, acquire input from overlying cortex. Combined electrical and optogenetic activation of thalamic afferents identified that Lpar1-EGFP SPNs receive sparse thalamic innervation. These data reveal components of the postnatal network that interpret sparse thalamic input to direct the emergent columnar structure of S1BF.

scholarly journals Layer-specific sensory processing impairment in the primary somatosensory cortex after motor cortex infarction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Atsushi Fukui ◽  
Hironobu Osaki ◽  
Yoshifumi Ueta ◽  
Kenta Kobayashi ◽  
Yoshihiro Muragaki ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Somatosensory Cortex ◽  
Sensory Processing ◽  
Primary Somatosensory Cortex

scholarly journals Context-Dependent Sensory Processing across Primary and Secondary Somatosensory Cortex

Neuron ◽  
2020 ◽  
Vol 106 (3) ◽  
pp. 515-525.e5 ◽  
Author(s):  
Cameron Condylis ◽  
Eric Lowet ◽  
Jianguang Ni ◽  
Karina Bistrong ◽  
Timothy Ouellette ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Sensory Processing ◽  
Secondary Somatosensory Cortex ◽  
Context Dependent

Spatial determinants of multisensory integration in cat superior colliculus neurons

1996 ◽  
Vol 75 (5) ◽  
pp. 1843-1857 ◽  
Author(s):  
M. A. Meredith ◽  
B. E. Stein
Keyword(s):  
Receptive Field ◽  
Superior Colliculus ◽  
Neuronal Response ◽  
Receptive Fields ◽  
Spatial Relationship ◽  
Physiological Role ◽  
Extracellular Recording ◽  
Average Proportion ◽  
Relationship Of ◽  
High Degree

1. Although a representation of multisensory space is contained in the superior colliculus, little is known about the spatial requirements of multisensory stimuli that influence the activity of neurons here. Critical to this problem is an assessment of the registry of the different receptive fields within individual multisensory neurons. The present study was initiated to determine how closely the receptive fields of individual multisensory neurons are aligned, the physiological role of that alignment, and the possible functional consequences of inducing receptive-field misalignment. 2. Individual multisensory neurons in the superior colliculus of anesthetized, paralyzed cats were studied with the use of standard extracellular recording techniques. The receptive fields of multisensory neurons were large, as reported previously, but exhibited a surprisingly high degree of spatial coincidence. The average proportion of receptive-field overlap was 86% for the population of visual-auditory neurons sampled. 3. Because of this high degree of intersensory receptive-field correspondence, combined-modality stimuli that were coincident in space tended to fall within the excitatory regions of the receptive fields involved. The result was a significantly enhanced neuronal response in 88% of the multisensory neurons studied. If stimuli were spatially disparate, so that one fell outside its receptive field, either a decreased response occurred (56%), or no intersensory effect was apparent (44%). 4. The normal alignment of the different receptive fields of a multisensory neuron could be disrupted by passively displacing the eyes, pinnae, or limbs/body. In no case was a shift in location or size observed in a neuron's other receptive field(s) to compensate for this displacement. The physiological result of receptive-field misalignment was predictable and based on the location of the stimuli relative to the new positions of their respective receptive fields. Now, for example, one component of a spatially coincident pair of stimuli might fall outside its receptive field and inhibit the other's effects. 5. These data underscore the dependence of multisensory integrative responses on the relationship of the different stimuli to their corresponding receptive fields rather than to the spatial relationship of the stimuli to one another. Apparently, the alignment of different receptive fields for individual multisensory neurons ensures that responses to combinations of stimuli derived from the same event are integrated to increase the salience of that event. Therefore the maintenance of receptive-field alignment is critical for the appropriate integration of converging sensory signals and, ultimately, elicitation of adaptive behaviors.

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