A cortico-cortical pathway targets inhibitory interneurons and modulates paw movement during locomotion in mice

The primary somatosensory cortex (S1) is important for the control of movement as it encodes sensory input from the body periphery and external environment during ongoing movement. Mouse S1 consists of several distinct sensorimotor subnetworks that receive topographically organized cortico-cortical inputs from distant sensorimotor areas, including the secondary somatosensory cortex (S2) and primary motor cortex (M1). The role of the vibrissal S1 area and associated cortical connections during active sensing is well documented, but whether (and if so, how) non-whisker S1 areas are involved in movement control remains relatively unexplored. Here, we demonstrate that unilateral silencing of the non-whisker S1 area in both male and female mice disrupts hind paw movement during locomotion on a rotarod and a runway. S2 and M1 provide major long range inputs to this S1 area. Silencing S2 to non whisker S1 projections alters the hind paw orientation during locomotion while manipulation of the M1 projection has little effect. Using patch clamp recordings in brain slices from male and female mice, we show that S2 projection preferentially innervates inhibitory interneuron subtypes. We conclude that S2 S1 corticocortical interactions mediated by local interneurons are critical for efficient locomotion.

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The effect of bilateral cold block of the primate face primary somatosensory cortex on the performance of trained tongue-protrusion task and biting tasks

Journal of Neurophysiology ◽

10.1152/jn.1993.70.3.985 ◽

1993 ◽

Vol 70 (3) ◽

pp. 985-996 ◽

Cited By ~ 45

Author(s):

L. D. Lin ◽

G. M. Murray ◽

B. J. Sessle

Keyword(s):

Somatosensory Cortex ◽

Primary Motor Cortex ◽

Movement Control ◽

Primary Somatosensory Cortex ◽

Emg Activity ◽

Success Rates ◽

Tongue Protrusion ◽

Reversible Inactivation ◽

Control Series ◽

Holding Period

1. Studies using ablation, intracortical microstimulation (ICMS) and surface stimulation, and single-neuron recordings have suggested that the primate primary somatosensory cortex (SI) may play an important role in movement control. Our aim was to determine whether bilateral inactivation of face SI would indeed interfere with the control of tongue or jaw-closing movements. 2. Effects of reversible inactivation by cooling of face SI was investigated in two monkeys trained to perform both a tongue-protrusion task and a biting task. The cooling experiments were carried out after the orofacial representation within SI was identified by systematically defining the mechanoreceptive field of single neurons recorded in face SI. The deficits in the tongue or jaw-closing movement were evaluated by the success rates for the monkeys' performance of both tasks and by the force and electromyographic (EMG) activity recorded from the masseter, genioglossus, and digastric muscles associated with the tasks. 3. During bilateral cooling of face SI, there was a statistically significant reduction in the success rates for the performance of the tongue-protrusion task in comparison with control series of trials while the thermodes used to cool face SI were kept at 37 degrees C. Detailed analyses of force and EMG activity showed that the principal deficit was the inability of the monkeys to maintain a steady tongue-protrusive force in the force holding period during each trial and to exert a consistent tongue-protrusion force between different trials. The task performance returned to control protocol levels at 4 min after commencement of rewarming. 4. Identical cooling conditions did not significantly affect the success rates for the performance of the biting task. Although the extent of the deficit was not severe enough to cause a significant reduction in successful rates for the biting task, cooling did significantly affect the ability of the monkeys to maintain a steady force in the holding period during each trial and to exert a consistent force between different trials. In one monkey the success rate of the biting task was also not affected by bilaterally cooling of face SI with a pair of larger thermodes placed on the dura over most of the face SI, face primary motor cortex (face MI), and adjacent cortical regions.(ABSTRACT TRUNCATED AT 400 WORDS)

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High-order thalamic inputs to primary somatosensory cortex are stronger and longer lasting than cortical inputs

eLife ◽

10.7554/elife.44158 ◽

2019 ◽

Vol 8 ◽

Cited By ~ 26

Author(s):

Wanying Zhang ◽

Randy M Bruno

Keyword(s):

Somatosensory Cortex ◽

Primary Motor Cortex ◽

Pyramidal Neurons ◽

Sensory Stimulation ◽

Primary Somatosensory Cortex ◽

Specific Substrate ◽

Medial Nucleus ◽

Posterior Medial Nucleus ◽

Cortical Inputs

Layer (L) 2/3 pyramidal neurons in the primary somatosensory cortex (S1) are sparsely active, spontaneously and during sensory stimulation. Long-range inputs from higher areas may gate L2/3 activity. We investigated their in vivo impact by expressing channelrhodopsin in three main sources of feedback to rat S1: primary motor cortex, secondary somatosensory cortex, and secondary somatosensory thalamic nucleus (the posterior medial nucleus, POm). Inputs from cortical areas were relatively weak. POm, however, more robustly depolarized L2/3 cells and, when paired with peripheral stimulation, evoked action potentials. POm triggered not only a stronger fast-onset depolarization but also a delayed all-or-none persistent depolarization, lasting up to 1 s and exhibiting alpha/beta-range oscillations. Inactivating POm somata abolished persistent but not initial depolarization, indicating a recurrent circuit mechanism. We conclude that secondary thalamus can enhance L2/3 responsiveness over long periods. Such timescales could provide a potential modality-specific substrate for attention, working memory, and plasticity.

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Motor planning brings human primary somatosensory cortex into action-specific preparatory states

eLife ◽

10.7554/elife.69517 ◽

2022 ◽

Vol 11 ◽

Author(s):

Giacomo Ariani ◽

J Andrew Pruszynski ◽

Jörn Diedrichsen

Keyword(s):

Somatosensory Cortex ◽

Motor Neurons ◽

Primary Motor Cortex ◽

Specific Activity ◽

Activity Patterns ◽

Critical Role ◽

Motor Planning ◽

Movement Control ◽

Movement Planning ◽

Primary Somatosensory Cortex

Motor planning plays a critical role in producing fast and accurate movement. Yet, the neural processes that occur in human primary motor and somatosensory cortex during planning, and how they relate to those during movement execution, remain poorly understood. Here we used 7T functional magnetic resonance imaging (fMRI) and a delayed movement paradigm to study single finger movement planning and execution. The inclusion of no-go trials and variable delays allowed us to separate what are typically overlapping planning and execution brain responses. Although our univariate results show widespread deactivation during finger planning, multivariate pattern analysis revealed finger-specific activity patterns in contralateral primary somatosensory cortex (S1), which predicted the planned finger action. Surprisingly, these activity patterns were as informative as those found in contralateral primary motor cortex (M1). Control analyses ruled out the possibility that the detected information was an artifact of subthreshold movements during the preparatory delay. Furthermore, we observed that finger-specific activity patterns during planning were highly correlated to those during execution. These findings reveal that motor planning activates the specific S1 and M1 circuits that are engaged during the execution of a finger press, while activity in both regions is overall suppressed. We propose that preparatory states in S1 may improve movement control through changes in sensory processing or via direct influence of spinal motor neurons.

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Single-cell molecular connectomics of intracortically-projecting neurons

10.1101/378760 ◽

2018 ◽

Cited By ~ 10

Author(s):

Esther Klingler ◽

Julien Prados ◽

Justus M Kebschull ◽

Alexandre Dayer ◽

Anthony M Zador ◽

...

Keyword(s):

Single Cell ◽

Somatosensory Cortex ◽

Primary Motor Cortex ◽

Neuronal Cell ◽

Cell Types ◽

Population Based ◽

Projection Mapping ◽

Secondary Somatosensory Cortex ◽

Axonal Projections ◽

Sensorimotor Transformations

The neocortex is organized into distinct areas, whose interconnectivity underlies sensorimotor transformations and integration1–7. These behaviorally critical functions are mediated by intracortically-projecting neurons (ICPN), which are a heterogeneous population of cells sending axonal branches to distinct cortical areas as well as to subcortical targets8–10. Although population-based11–14 and single-cell15–19 intracortical wiring diagrams are being identified, the transcriptional signatures corresponding to single-cell axonal projections of ICPN to multiple sites remain unknown. To address this question, we developed a high-throughput approach, “ConnectID”, to link connectome and transcriptome in single neurons. ConnectID combines MAPseq projection mapping17,20 (to identify single-neuron multiplex projections) with single-cell RNA sequencing (to identify corresponding gene expression). Using primary somatosensory cortex (S1) ICPN as proof-of-principle neurons, we identify three cardinal targets: (1) the primary motor cortex (M1), (2) the secondary somatosensory cortex (S2) and (3) subcortical targets (Sub). Using ConnectID, we identify transcriptional modules whose combined activities reflect multiplex projections to these cardinal targets. Based on these findings, we propose that the combinatorial activity of connectivity-defined transcriptional modules serves as a generic molecular mechanism to create diverse axonal projection patterns within and across neuronal cell types.

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Effects of looming and static sounds on somatosensory processing: A MEG study

Seeing and Perceiving ◽

10.1163/187847612x647270 ◽

2012 ◽

Vol 25 (0) ◽

pp. 94

Author(s):

Elisa Leonardelli ◽

Valeria Occelli ◽

Gianpaolo Demarchi ◽

Massimo Grassi ◽

Christoph Braun ◽

...

Keyword(s):

Somatosensory Cortex ◽

Time Window ◽

The Body ◽

Head Model ◽

Somatosensory Processing ◽

Global Field Power ◽

Secondary Somatosensory Cortex ◽

Head Space ◽

Extrapersonal Space ◽

Significant Difference

The present study aims to assess the mechanisms involved in the processing of potentially threatening stimuli presented within the peri-head space of humans. Magnetic fields evoked by air-puffs presented at the peri-oral area of fifteen participants were recorded by using magnetoencephalography (MEG). Crucially, each air puff was preceded by a sound, which could be either perceived as looming, stationary and close to the body (i.e., within the peri-head space) or stationary and far from the body (i.e., extrapersonal space). The comparison of the time courses of the global field power (GFP) indicated a significant difference in the time window ranging from 70 to 170 ms between the conditions. When the air puff was preceded by a stationary sound located far from the head stronger somatosensory activity was evoked as compared to the conditions where the sounds were located close to the head. No difference could be shown for the looming and the stationary prime stimulus close to the head. Source localization was performed assuming a pair of symmetric dipoles in a spherical head model that was fitted to the MRI images of the individual participants. Results showed sources in primary and secondary somatosensory cortex. Source activities in secondary somatosensory cortex differed between the three conditions, with larger effects evoked by the looming sounds and smaller effects evoked by the far stationary sounds, and the close stationary sounds evoking intermediate effects. Overall, these findings suggest the existence of a system involved in the detection of approaching objects and protecting the body from collisions in humans.

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Dose and time-dependent acute and subchronic oral toxicity study of propoxazepam in mice and rats

International Journal of Pharmacology and Toxicology ◽

10.14419/ijpt.v8i1.29531 ◽

2020 ◽

Vol 8 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Nikolay Yakovlevich Golovenko ◽

Valentina Nikolayevna Kovalenko ◽

Vitalii Borisovich Larionov ◽

Аnatoliy Semenovich Reder

Keyword(s):

Body Weight ◽

Acute Toxicity ◽

Oral Administration ◽

The Body ◽

Toxicity Study ◽

Male Rats ◽

Toxicity Tests ◽

Male And Female ◽

Organ Weights ◽

Female Mice

Propoxazepam, 7-bromo-5 - (o-chlorophenyl)-3-propoxy - 1,2-dihydro - 3H-1,4-benzodiazepin-2-one, in the models of nociceptive and neuropathic pain showed significant analgesic activity. In order to explore clinical potential of propoxazepam for long term human consumption, toxicology testing in laboratory animals using well-accepted international guidelines is required. Acute toxicity tests were conducted by the oral administration of 2500; 3500; 4000; 4500 and 5000 mg/kg body weight to male and female mice and rats for a period of 3, 7 and 14 day. In subacute study, male rats were administered with various doses of propoxazepam (0.9, 4.5, and 9.0 mg/kg) to evaluate its toxicity for a period of 90 days. The effect of propoxazepam on body weight gain and organ weights, food and water consumptions were analyzed. From the present study, it can be concluded that the acute (3, 7 and 14 days) and subchronic (90 days) oral administrations of propoxazepam did not produce any clinical signs of toxicity or mortality of the male and female mice and rats. These results revealed that the LD50 of propoxazepam is greater than 5000 mg/kg and it therefore, belongs to the category V of relatively non-toxic substances according to the GHS. In the acute toxicity study, neither mortality no significant change in the body weight and the relative organ weights were recorded in all treated mice and rats. Present data set revealed that there wasn`t a strong correlation between body weight with food and water consumptions. The result indicates that the oral administration of propoxazepam did not produce any significant toxic effect in mice and rats and the substance can be safely used for therapeutic use in pharmaceutical formulations.

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Unique properties of high-order thalamic inputs versus cortical inputs to primary somatosensory cortex

10.1101/495218 ◽

2018 ◽

Author(s):

Elaine Zhang ◽

Randy M Bruno

Keyword(s):

Somatosensory Cortex ◽

Primary Motor Cortex ◽

Pyramidal Neurons ◽

Sensory Stimulation ◽

Primary Somatosensory Cortex ◽

Specific Substrate ◽

Medial Nucleus ◽

Posterior Medial Nucleus ◽

Cortical Inputs

Layer (L) 2/3 pyramidal neurons in the primary somatosensory cortex (S1) are sparsely active, spontaneously and during sensory stimulation. Long-range inputs from higher areas may gate L2/3 activity. We investigated their in vivo impact by expressing channelrhodopsin in three main sources of feedback to rat S1: primary motor cortex, secondary somatosensory cortex, and secondary somatosensory thalamic nucleus (the posterior medial nucleus, POm). Inputs from cortical areas were relatively weak. POm, however, more robustly depolarized L2/3 cells and, when paired with peripheral stimulation, evoked action potentials. POm triggered not only a stronger fast-onset depolarization but also a delayed all-or-none persistent depolarization, lasting up to 1 second and exhibiting beta oscillations. Inactivating POm somata abolished persistent but not initial depolarization, indicating a recurrent circuit mechanism. We conclude that secondary thalamus can enhance L2/3 responsiveness over long periods. Such timescales could provide a potential modality-specific substrate for attention, working memory, and plasticity.

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Ipsilateral stimulus encoding in primary and secondary somatosensory cortex of awake mice

10.1101/2021.07.16.452704 ◽

2021 ◽

Author(s):

Aurélie Pala ◽

Garrett B Stanley

Keyword(s):

Somatosensory Cortex ◽

The Body ◽

Mammalian Brain ◽

Equal Proportion ◽

Somatosensory Processing ◽

Secondary Somatosensory Cortex ◽

Tactile Stimuli ◽

Somatosensory Cortices ◽

Stimulus Responsive ◽

Layer 4

Lateralization is a hallmark of somatosensory processing in the mammalian brain. However, in addition to their contralateral representation, unilateral tactile stimuli also modulate neuronal activity in somatosensory cortices of the ipsilateral hemisphere. The cellular organization and functional role of these ipsilateral stimulus responses in awake somatosensory cortices, especially regarding stimulus coding, are unknown. Here, we targeted silicon probe recordings to the vibrissa region of primary (S1) and secondary (S2) somatosensory cortex of awake head-fixed male and female mice while delivering ipsilateral and contralateral whisker stimuli. Ipsilateral stimuli drove larger and more reliable responses in S2 than in S1, and activated a larger fraction of stimulus-responsive neurons. Ipsilateral stimulus-responsive neurons were rare in layer 4 of S1, but were located in equal proportion across all layers in S2. Linear classifier analyses further revealed that decoding of the ipsilateral stimulus was more accurate in S2 than S1, while S1 decoded contralateral stimuli most accurately. These results reveal substantial encoding of ipsilateral stimuli in S1 and especially S2, consistent with the hypothesis that higher cortical areas may integrate tactile inputs across larger portions of space, spanning both sides of the body.

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