scholarly journals Behavioral State Dependency of Neural Activity and Sensory (Whisker) Responses in Superior Colliculus

2010 ◽  
Vol 104 (3) ◽  
pp. 1661-1672 ◽  
Author(s):  
Jeremy D. Cohen ◽  
Manuel A. Castro-Alamancos

Rats use their vibrissa (whiskers) to explore and navigate the environment. These sensory signals are distributed within the brain stem by the trigeminal complex and are also relayed to the superior colliculus in the midbrain and to the thalamus (and subsequently barrel cortex) in the forebrain. In the intermediate layers of the superior colliculus, whisker-evoked responses are driven by direct inputs from the trigeminal complex (trigeminotectal) and feedback from the barrel cortex (corticotectal). But the effects of the behavioral state of the animal on the spontaneous firing and sensory responses of these neurons are unknown. By recording from freely behaving rats, we show that the spontaneous firing of whisker sensitive neurons in superior colliculus is higher, or in an activated mode, during active exploration and paradoxical sleep and much lower, or in a quiescent/deactivated mode, during awake immobility and slow-wave sleep. Sensory evoked responses in superior colliculus also depend on behavioral state. Most notably, feedback corticotectal responses are significantly larger during the quiescent/deactivated mode, which tracks the barrel cortex responses on which they depend. Finally, sensory evoked responses depend not only on the state of the animal but also on the orienting response elicited by the stimulus, which agrees with the well known role of the superior colliculus in orienting about salient stimuli.

2019 ◽  
Vol 13 ◽  
Author(s):  
Julia Lebedeva ◽  
Andrey Zakharov ◽  
Gulshat Burkhanova ◽  
Kseniya Chernova ◽  
Roustem Khazipov

2016 ◽  
Vol 7 (2) ◽  
pp. 378-381
Author(s):  
Daria Vinokurova ◽  
Andrey Zakharov ◽  
Dinara Akhmetshina ◽  
Azat Nasretdinov ◽  
Guzel Valeeva ◽  
...  

2015 ◽  
Vol 112 (45) ◽  
pp. 14072-14077 ◽  
Author(s):  
Robert Egger ◽  
Arno C. Schmitt ◽  
Damian J. Wallace ◽  
Bert Sakmann ◽  
Marcel Oberlaender ◽  
...  

Cortical inhibitory interneurons (INs) are subdivided into a variety of morphologically and functionally specialized cell types. How the respective specific properties translate into mechanisms that regulate sensory-evoked responses of pyramidal neurons (PNs) remains unknown. Here, we investigated how INs located in cortical layer 1 (L1) of rat barrel cortex affect whisker-evoked responses of L2 PNs. To do so we combined in vivo electrophysiology and morphological reconstructions with computational modeling. We show that whisker-evoked membrane depolarization in L2 PNs arises from highly specialized spatiotemporal synaptic input patterns. Temporally L1 INs and L2–5 PNs provide near synchronous synaptic input. Spatially synaptic contacts from L1 INs target distal apical tuft dendrites, whereas PNs primarily innervate basal and proximal apical dendrites. Simulations of such constrained synaptic input patterns predicted that inactivation of L1 INs increases trial-to-trial variability of whisker-evoked responses in L2 PNs. The in silico predictions were confirmed in vivo by L1-specific pharmacological manipulations. We present a mechanism—consistent with the theory of distal dendritic shunting—that can regulate the robustness of sensory-evoked responses in PNs without affecting response amplitude or latency.


2020 ◽  
Author(s):  
Guillaume Bony ◽  
Arjun A Bhaskaran ◽  
Katy Le Corf ◽  
Andreas Frick

ABSTRACTThe mouse primary somatosensory cortex (S1) processes tactile sensory information and is the largest neocortex area emphasizing the importance of this sensory modality for rodent behavior. Most of our knowledge regarding information processing in S1 stems from studies of the whisker-related barrel cortex (S1–BC), yet the processing of tactile inputs from the hind-paws is poorly understood. We used in vivo whole-cell patch-clamp recordings from layer (L) 2/3 pyramidal neurons (PNs) of the S1 hind-paw (S1-HP) region of anaesthetized wild type (WT) mice to investigate their evoked sub- and supra-threshold activity, intrinsic properties, and spontaneous activity. Approximately 45% of these L2/3 PNs responded to brief contralateral HP stimulation in a subthreshold manner, ~5% fired action potentials, and ~50% of L2/3 PNs did not respond at all. The evoked subthreshold responses had long onset- (~23 ms) and peak-latencies (~61 ms). The majority (86%) of these L2/3 PNs responded to prolonged (stance-like) HP stimulation with both on- and off-responses. HP stimulation responsive L2/3 PNs had a greater intrinsic excitability compared to non-responsive ones, possibly reflecting differences in their physiological role. Similar to S1-BC, L2/3 PNs displayed up- and down-states, and low spontaneous firing rates (~0.1 Hz). Our findings support a sparse coding scheme of operation for S1–HP L2/3 PNs and highlight both differences and similarities with L2/3 PNs from other somatosensory cortex areas.KEY POINTSResponses of layer (L) 2/3 pyramidal neurons (PNs) of the primary somatosensory hind-paw cortex (S1-HP) to contralateral hind-paw stimulation reveal both differences and similarities compared to those of somatosensory neurons responding to other tactile (e.g. whiskers, forepaw, tongue) modalities.Similar to whisker-related barrel cortex (S1-BC) and forepaw cortex (S1-FP) S1-HP L2/3 PNs show a low spontaneous firing rate and a sparse action potential coding of evoked activity.In contrast to S1-BC, brief hind-paw stimulus evoked responses display a long latency in S1-HP neurons consistent with their different functional role.The great majority of L 2/3 PNs respond to prolonged hind-paw stimulation with both on- and off-responses.These results help us to better understand sensory information processing within layer 2/3 of the neocortex and the regional differences related to various tactile modalities.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
William A. Zeiger ◽  
Máté Marosi ◽  
Satvir Saggi ◽  
Natalie Noble ◽  
Isa Samad ◽  
...  

AbstractRecovery after stroke is thought to be mediated by adaptive circuit plasticity, whereby surviving neurons assume the roles of those that died. However, definitive longitudinal evidence of neurons changing their response selectivity after stroke is lacking. We sought to directly test whether such functional “remapping” occurs within mouse primary somatosensory cortex after a stroke that destroys the C1 barrel. Using in vivo calcium imaging to longitudinally record sensory-evoked activity under light anesthesia, we did not find any increase in the number of C1 whisker-responsive neurons in the adjacent, spared D3 barrel after stroke. To promote plasticity after stroke, we also plucked all whiskers except C1 (forced use therapy). This led to an increase in the reliability of sensory-evoked responses in C1 whisker-responsive neurons but did not increase the number of C1 whisker-responsive neurons in spared surround barrels over baseline levels. Our results argue against remapping of functionality after barrel cortex stroke, but support a circuit-based mechanism for how rehabilitation may improve recovery.


2021 ◽  
Author(s):  
Abhishek S. Bhutada ◽  
Chang Cai ◽  
Danielle Mizuiri ◽  
Anne Findlay ◽  
Jessie Chen ◽  
...  

AbstractMagnetoencephalography (MEG) is a robust method for non-invasive functional brain mapping of sensory cortices due to its exceptional spatial and temporal resolution. The clinical standard for MEG source localization of functional landmarks from sensory evoked responses is the equivalent current dipole (ECD) localization algorithm, known to be sensitive to initialization, noise, and manual choice of the number of dipoles. Recently many automated and robust algorithms have been developed, including the Champagne algorithm, an empirical Bayesian algorithm, with powerful abilities for MEG source reconstruction and time course estimation (Wipf et al. 2010; Owen et al. 2012). Here, we evaluate automated Champagne performance in a clinical population of tumor patients where there was minimal failure in localizing sensory evoked responses using the clinical standard, ECD localization algorithm. MEG data of auditory evoked potentials and somatosensory evoked potentials from 21 brain tumor patients were analyzed using Champagne, and these results were compared with equivalent current dipole (ECD) fit. Across both somatosensory and auditory evoked field localization, we found there was a strong agreement between Champagne and ECD localizations in all cases. Given resolution of 8mm voxel size, peak source localizations from Champagne were below 10mm of ECD peak source localization. The Champagne algorithm provides a robust and automated alternative to manual ECD fits for clinical localization of sensory evoked potentials and can contribute to improved clinical MEG data processing workflows.


1985 ◽  
Vol 2 (3) ◽  
pp. 187-206 ◽  
Author(s):  
JUDY R. MACKEY-HARGADINE ◽  
JAMES W. HALL

1979 ◽  
Vol 237 (1) ◽  
pp. R80-R88 ◽  
Author(s):  
S. Sakaguchi ◽  
S. F. Glotzbach ◽  
H. C. Heller

Unanesthetized, unrestrained kangaroo rats (Dipodomys) were studied to examine the changes in the frequency and duration of sleep states caused by long-term manipulations of hypothalamic temperature (Thy) at a thermoneutral (30 degrees C) and a low (20 degrees C) ambient temperature (Ta). A cold stimulus present in either the hypothalamus or the skin decreased both the total sleep time (TST) and the ratio of paradoxical sleep (PS) to TST. At a low Ta, TST, but not the PS-to-TST ratio, was increased by raising Thy, indicating that a cold peripheral stimulus could differentially inhibit PS. At a thermoneutral Ta, cooling Thy decreased both TST and the PS/TST. Changes in the amount of PS were due largely to changes in the frequency, but not the duration, of individual episodes of PS, suggesting that the transition to PS is partially dependent on the thermoregulatory conditions existing during slow-wave sleep (SWS). These results are consistent with the recent findings that the thermoregulatory system is functional during SWS but is inhibited or inactivated during PS.


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