scholarly journals Activity of motor cortex neurons during backward locomotion

2011 ◽  
Vol 105 (6) ◽  
pp. 2698-2714 ◽  
Author(s):  
P. V. Zelenin ◽  
T. G. Deliagina ◽  
G. N. Orlovsky ◽  
A. Karayannidou ◽  
E. E. Stout ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Cortical Neurons ◽  
Cortical Activity ◽  
The Other ◽  
Bipedal Locomotion ◽  
Related Activity ◽  
Quadrupedal Locomotion ◽  
Functional Roles ◽  
Recorded Activity ◽  
Almost All

Forward walking (FW) and backward walking (BW) are two important forms of locomotion in quadrupeds. Participation of the motor cortex in the control of FW has been intensively studied, whereas cortical activity during BW has never been investigated. The aim of this study was to analyze locomotion-related activity of the motor cortex during BW and compare it with that during FW. For this purpose, we recorded activity of individual neurons in the cat during BW and FW. We found that the discharge frequency in almost all neurons was modulated in the rhythm of stepping during both FW and BW. However, the modulation patterns during BW and FW were different in 80% of neurons. To determine the source of modulating influences (forelimb controllers vs. hindlimb controllers), the neurons were recorded not only during quadrupedal locomotion but also during bipedal locomotion (with either forelimbs or hindlimbs walking), and their modulation patterns were compared. We found that during BW (like during FW), modulation in some neurons was determined by inputs from limb controllers of only one girdle, whereas the other neurons received inputs from both girdles. The combinations of inputs could depend on the direction of locomotion. Most often (in 51% of forelimb-related neurons and in 34% of the hindlimb-related neurons), the neurons received inputs only from their own girdle when this girdle was leading and from both girdles when this girdle was trailing. This reconfiguration of inputs suggests flexibility of the functional roles of individual cortical neurons during different forms of locomotion.

scholarly journals State-dependent modulation of activity in distinct layer 6 corticothalamic neurons in barrel cortex of awake mice

2021 ◽  
Author(s):  
Suryadeep Dash ◽  
Dawn M Autio ◽  
Shane R Crandall
Keyword(s):  
Cortical Neurons ◽  
Barrel Cortex ◽  
Related Activity ◽  
Functional Roles ◽  
Firing Rates ◽  
State Dependent ◽  
Rich Diversity ◽  
Response Profiles ◽  
Strategic Position ◽  
Activity Dependent

Layer 6 corticothalamic (L6 CT) neurons are in a strategic position to control sensory input to the neocortex, yet we understand very little about their functions. Apart from studying their anatomical, physiological and synaptic properties, most recent efforts have focused on the activity-dependent influences CT cells can exert on thalamic and cortical neurons through causal optogenetic manipulations. However, few studies have attempted to study them during behavior. In an attempt to address this gap, we performed juxtacellular recordings from optogenetically identified CT neurons in whisker-related primary somatosensory cortex (wS1) of awake, head-fixed mice (of either sex) free to rest quietly or self-initiate bouts of whisking and locomotion. We found a rich diversity of response profiles exhibited by CT cells. Broadly, their spiking patterns were either modulated by whisker-related behavior (~28%) or not (~72%). Whisker-related neurons exhibited both increases as well as decreases in firing rates. We also encountered cells with preceding modulations in firing rate before whisking onset. Overall, whisking better explained these changes in rates than overall changes in arousal. The CT cells that showed no whisker-related activity had low spontaneous firing rates (<0.5 Hz), with many all but silent. Remarkably, this relatively silent population preferentially spiked at the state transition point when pupil diameter constricted and the mouse entered quiet wakefulness. Thus, our results demonstrate that L6 CT neurons in wS1 show diverse spiking patterns, perhaps subserving distinct functional roles related to precisely timed responses during complex behaviors and transitions between discrete waking states.

scholarly journals Phenotypic variation within and across transcriptomic cell types in mouse motor cortex

2020 ◽  
Author(s):  
Federico Scala ◽  
Dmitry Kobak ◽  
Matteo Bernabucci ◽  
Yves Bernaerts ◽  
Cathryn René Cadwell ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Cortical Neurons ◽  
Adult Mouse ◽  
Cell Types ◽  
Neuronal Diversity ◽  
Patch Clamp Recording ◽  
Electrophysiological Properties ◽  
Single Cell Rna Sequencing ◽  
Electric Space ◽  
Almost All

Cortical neurons exhibit astounding diversity in gene expression as well as in morphological and electrophysiological properties. Most existing neural taxonomies are based on either transcriptomic or morpho-electric criteria, as it has been technically challenging to study both aspects of neuronal diversity in the same set of cells. Here we used Patch-seq to combine patch-clamp recording, biocytin staining, and single-cell RNA sequencing of over 1300 neurons in adult mouse motor cortex, providing a comprehensive morpho-electric annotation of almost all transcriptomically defined neural cell types. We found that, although broad families of transcriptomic types (Vip, Pvalb, Sst, etc.) had distinct and essentially non-overlapping morpho-electric phenotypes, individual transcriptomic types within the same family were not well-separated in the morpho-electric space. Instead, there was a continuum of variability in morphology and electrophysiology, with neighbouring transcriptomic cell types showing similar morpho-electric features, often without clear boundaries between them. Our results suggest that neural types in the neocortex do not always form discrete entities. Instead, neurons follow a hierarchy consisting of distinct non-overlapping branches at the level of families, but can form continuous and correlated transcriptomic and morpho-electrical landscapes within families.

scholarly journals Phenotypic variation of transcriptomic cell types in mouse motor cortex

Nature ◽  
2020 ◽  
Author(s):  
Federico Scala ◽  
Dmitry Kobak ◽  
Matteo Bernabucci ◽  
Yves Bernaerts ◽  
Cathryn René Cadwell ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Cortical Neurons ◽  
Primary Motor Cortex ◽  
Cell Types ◽  
Neuronal Diversity ◽  
Patch Clamp Recording ◽  
Electrophysiological Properties ◽  
Neuronal Types ◽  
Electric Space ◽  
Almost All

AbstractCortical neurons exhibit extreme diversity in gene expression as well as in morphological and electrophysiological properties1,2. Most existing neural taxonomies are based on either transcriptomic3,4 or morpho-electric5,6 criteria, as it has been technically challenging to study both aspects of neuronal diversity in the same set of cells7. Here we used Patch-seq8 to combine patch-clamp recording, biocytin staining, and single-cell RNA sequencing of more than 1,300 neurons in adult mouse primary motor cortex, providing a morpho-electric annotation of almost all transcriptomically defined neural cell types. We found that, although broad families of transcriptomic types (those expressing Vip, Pvalb, Sst and so on) had distinct and essentially non-overlapping morpho-electric phenotypes, individual transcriptomic types within the same family were not well separated in the morpho-electric space. Instead, there was a continuum of variability in morphology and electrophysiology, with neighbouring transcriptomic cell types showing similar morpho-electric features, often without clear boundaries between them. Our results suggest that neuronal types in the neocortex do not always form discrete entities. Instead, neurons form a hierarchy that consists of distinct non-overlapping branches at the level of families, but can form continuous and correlated transcriptomic and morpho-electrical landscapes within families.

scholarly journals Multi-dimensional tuning in motor cortical neurons during active behavior

2020 ◽  
Author(s):  
Rachel C. Yuan ◽  
Sarah W. Bottjer
Keyword(s):  
Motor Cortex ◽  
Motor Skills ◽  
Cortical Neurons ◽  
Cortical Activity ◽  
Single Neurons ◽  
Active Behavior ◽  
Complex Motor ◽  
Freely Behaving ◽  
Motor Cortical ◽  
Complex Motor Skills

ABSTRACTA region within songbird cortex, AId (dorsal intermediate arcopallium), is functionally analogous to motor cortex in mammals and has been implicated in vocal learning during development. AId thus serves as a powerful model for investigating motor cortical contributions to developmental skill learning. We made extracellular recordings in AId of freely behaving juvenile zebra finches and evaluated neural activity during diverse motor behaviors throughout entire recording sessions, including song production as well as hopping, pecking, preening, fluff-ups, beak interactions with cage objects, scratching, and stretching. A large population of single neurons showed significant modulation of activity during singing relative to quiescence. In addition, AId neurons demonstrated heterogeneous response patterns that were evoked during multiple movements, with single neurons often demonstrating excitation during one movement type and suppression during another. Lesions of AId do not disrupt vocal motor output or impair generic movements, suggesting that the responses observed during active behavior do not reflect direct motor drive. Consistent with this idea, we found that some AId neurons showed differential activity during pecking movements depending on the context in which pecks occurred, suggesting that AId circuitry encodes diverse inputs beyond generic motor parameters. Moreover, we found evidence of neurons that did not respond during discrete movements but were nonetheless modulated during active behavioral states compared to quiescence. Taken together, our results support the idea that AId neurons are involved in sensorimotor integration of external sensory inputs and/or internal feedback cues to help modulate goal-directed behaviors.SIGNIFICANCE STATEMENTMotor cortex across taxa receives highly integrated, multi-modal information and has been implicated in both execution and acquisition of complex motor skills, yet studies of motor cortex typically employ restricted behavioral paradigms that target select movement parameters, preventing wider assessment of the diverse sensorimotor factors that can affect motor cortical activity. Recording in AId of freely behaving juvenile songbirds that are actively engaged in sensorimotor learning offers unique advantages for elucidating the functional role of motor cortical neurons. The results demonstrate that a diverse array of factors modulate motor cortical activity and lay important groundwork for future investigations of how multi-modal information is integrated in motor cortical regions to contribute to learning and execution of complex motor skills.

Motor Cortical Activity during Interception of Moving Targets.

2001 ◽  
Vol 13 (3) ◽  
pp. 306-318 ◽  
Author(s):  
Nicholas L. Port ◽  
Wolfgang Kruse ◽  
Daeyeol Lee ◽  
Apostolos P. Georgopoulos
Keyword(s):  
Motor Cortex ◽  
Cortical Neurons ◽  
Primary Motor Cortex ◽  
Movement Time ◽  
Hand Movement ◽  
Cortical Activity ◽  
Target Motion ◽  
Moving Target ◽  
Movement Initiation ◽  
Motor Cortical

The single-unit activity of 831 cells was recorded in the arm area of the motor cortex of tow monkeys while the monkeys intercepted a moving visual stimulus (interception task) or remained immobile during presentation of the same moving stimulus (no-go task). The moving target traveled on an oblique path from either lower corner of a screen toward the vertical meridian, and its movement time (0.5,1.0, or 1.5 sec) and velocity profile (accelerating, decelerating, or constant velocity) were pseudorandomly varied. The moving target had to be intercepted within 130 msec of target arrival at an interception point. By comparing motor cortical activity at the single-neuron tasks, we tested whether information about parameters of moving target is represented in the primary motor cortex to generate appropriate motor responses. A substantial number of neurons displayed modulation of their activity during the no-go task, and this activity was often affected by the stimulus parameters. These results suggest a role of motor cortex in specifying the timing of movement initiation based on information about target motion. In addition, there was a lack of systematic relation between the onset times of neural activity in the interception and no-go task, suggesting that processing of information concerning target motion and generation of hand movement occurs in parallel. Finally, the activity in the most motor cortical neurons was modulated according to an estimate of the time-to-target interception, raising the possibility that time-to-interception may be coded in the motor cortical activity.

Starość w nauczaniu św. Bazylego Wielkiego

Vox Patrum ◽  
2011 ◽  
Vol 56 ◽  
pp. 339-348
Author(s):  
Bogdan Czyżewski
Keyword(s):  
Old Age ◽  
Spiritual Maturity ◽  
The Other ◽  
Interesting Aspect ◽  
Other Hand ◽  
Physical Suffering ◽  
Way Of Thinking ◽  
Almost All

Although St. Basil did not live 50 years, the topic of the old age appears in his works quite often. On the other hand, it is clear that Basil does not discuss this issue in one par­ticular work or in the longer argumentation. The fragmentary statements about old age can be found in almost all his works, but most of them can be found in the correspondence of Basil. In this paper we present the most important ad the most interesting aspect of teach­ing of Basil the Great. As these certificates show that the bishop of Caesarea looked at the old age maturely, rationally estimated passage of time, which very often makes a man different. He experienced it, for example as a spiritual and physical suffering, which often were connected with his person. He saw a lot of aspect of the old age, especially its advan­tages – spiritual maturity and wisdom. What is more, he pointed also to passage of time, which leads a man to eternity, which should be prepared to, regardless how old he is. In his opinion fear is not seen opinions of St. Basil present really Christian way of thinking, well-balanced and calm.

Descriptions of the larvae of four species of Procladius from Great Slave Lake (Chironomidae:Diptera)

1978 ◽  
Vol 56 (9) ◽  
pp. 2055-2057 ◽  
Author(s):  
J. W. Moore ◽  
I. A. Moore
Keyword(s):  
Antennal Segment ◽  
The Other ◽  
Large Size ◽  
Great Slave Lake ◽  
Palpal Segment ◽  
Almost All

Descriptions of larvae of Procladius denticulatus, Procladius culiciformis, Procladius freemani, and Procladius bellus collected from Yellowknife Bay (lat., 62°25′; long., 114°20′) are given. Procladius denticulatus was separated from the other species by its large size, a character which always proved distinctive. Procladius culiciformis and P. freemani were separated from one another through several measurements including those of the basal antennal segment and the basal palpal segment. Almost all characters of the head were useful in distinguishing the much smaller P. bellus from the other species.

scholarly journals Geographical matching of volatile signals and pollinator olfactory responses in a cycad brood-site mutualism

2015 ◽  
Vol 282 (1816) ◽  
pp. 20152053 ◽  
Author(s):  
Terence N. Suinyuy ◽  
John S. Donaldson ◽  
Steven D. Johnson
Keyword(s):  
Choice Experiments ◽  
Local Region ◽  
The Other ◽  
Beetle Species ◽  
Olfactory Preference ◽  
Olfactory Responses ◽  
Volatile Emissions ◽  
Extant Species ◽  
Insect Pollinators ◽  
Almost All

Brood-site mutualisms represent extreme levels of reciprocal specialization between plants and insect pollinators, raising questions about whether these mutualisms are mediated by volatile signals and whether these signals and insect responses to them covary geographically in a manner expected from coevolution. Cycads are an ancient plant lineage in which almost all extant species are pollinated through brood-site mutualisms with insects. We investigated whether volatile emissions and insect olfactory responses are matched across the distribution range of the African cycad Encephalartos villosus . This cycad species is pollinated by the same beetle species across its distribution, but cone volatile emissions are dominated by alkenes in northern populations, and by monoterpenes and a pyrazine compound in southern populations. In reciprocal choice experiments, insects chose the scent of cones from the local region over that of cones from the other region. Antennae of beetles from northern populations responded mainly to alkenes, while those of beetles from southern populations responded mainly to pyrazine. In bioassay experiments, beetles were most strongly attracted to alkenes in northern populations and to the pyrazine compound in southern populations. Geographical matching of cone volatiles and pollinator olfactory preference is consistent with coevolution in this specialized mutualism.

Anna Karenina: The Dialectic of Prophecy

PMLA ◽  
1964 ◽  
Vol 79 (3) ◽  
pp. 266-282
Author(s):  
David H. Stewart
Keyword(s):  
Nineteenth Century ◽  
The Other ◽  
Moby Dick ◽  
Anna Karenina ◽  
Symbolic Value ◽  
Almost All ◽  
The Way

One of the most impressive features of Anna Karenina is the way in which Tolstoy draws the reader's imagination beyond the literal level of the narrative into generalizations that seem mythical in a manner difficult to articulate. With Dostoevsky or Melville, one sees immediately a propensity for exploiting the symbolic value of things. With Tolstoy, things try, as it were, to resist conversion: they strive to maintain their “thingness” as empirical entities. A character in Dostoevsky is usually only half man; the other half is Christ or Satan. Moby Dick is obviously only half whale; the other half is Evil or some principle of Nature. But Anna Karenina is emphatically Anna Karenina. Like almost all of Tolstoy's characters, she has a proficiency in the husbandry of identity; she jealously hoards her own unique reality, so that it becomes difficult to say of her that she is a “type” of nineteenth-century Russian lady or a “symbol” of modern woman or an “archetypical” Eve or Lilith.

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