scholarly journals Recording from the same neurons chronically in motor cortex

2012 ◽  
Vol 107 (7) ◽  
pp. 1970-1978 ◽  
Author(s):  
George W. Fraser ◽  
Andrew B. Schwartz
Keyword(s):  
Motor Cortex ◽  
Firing Rate ◽  
Neural Activity ◽  
Rhesus Monkeys ◽  
Single Units ◽  
Reaching Task ◽  
Firing Properties ◽  
Silicon Arrays ◽  
Over Time ◽  
Similarity Scores

Two rhesus monkeys were implanted with silicon arrays of 96 microelectrodes. Neural activity was recorded periodically over a period of weeks to months. We have developed a method to determine whether single units in two separate recording sessions represent the same neuron. Pairwise cross-correlograms, the autocorrelogram, waveform shape, and mean firing rate were used together as identifying features of a neuron. When two units recorded on separate days were compared using these features, their similarity scores tended to be either high, indicating two recordings from the same neuron, or low, indicating different neurons. Although these metrics are individually weak, together they produce a strong classifier. Some neurons were recorded for >100 days. These monkeys performed a center-out reaching task, and we found that the firing properties of chronically recorded neurons were stable over time.

Large-Scale Organization of Preferred Directions in the Motor Cortex. II. Analysis of Local Distributions

2006 ◽  
Vol 96 (6) ◽  
pp. 3237-3247 ◽  
Author(s):  
Thomas Naselaris ◽  
Hugo Merchant ◽  
Bagrat Amirikian ◽  
Apostolos P. Georgopoulos
Keyword(s):  
Motor Cortex ◽  
Neural Activity ◽  
Large Scale ◽  
Primary Motor Cortex ◽  
Spatial Arrangement ◽  
Companion Paper ◽  
Cortical Region ◽  
Population Vector ◽  
Reaching Task ◽  
Scale Properties

The spatial arrangement of preferred directions (PDs) in the primary motor cortex has revealed evidence for columnar organization and short-range order. We investigated the large-scale properties of this arrangement. We recorded neural activity at sites on a grid covering a large region of the arm area of the motor cortex while monkeys performed a 3D reaching task. Sites were projected to the cortical surface along anatomically defined cortical columns and a PD was extracted from each site with directionally tuned activity. We analyzed the resulting 2D surface map of PDs. Consistent with previous studies, we found that any particular reaching direction was rerepresented at many points across the recorded area. In particular, we determined that the median radius of a cortical region required to represent the full complement of reaching directions is at most 1 mm. We also found that for the majority of regions of this size, the distribution of PDs within them exhibits an enrichment for the representation of forward and backward reaching directions (see companion paper). Finally, we found that the error of a population vector estimate of reaching direction constructed from neural activity within these regions is small on average, but varies significantly across different sections of the motor cortex, with the highest levels of error sustained near the fundus of the central sulcus and lowest levels achieved near the crown. We interpret these findings in the context of two well-known features of motor cortex, that is, its highly distributed anatomical organization and its behaviorally dependent plasticity.

scholarly journals Spatio-temporal structure of single neuron subthalamic activity in Tourette Syndrome explored during DBS procedures

2019 ◽  
Author(s):  
Matteo Vissani ◽  
Roberto Cordella ◽  
Silvestro Micera ◽  
Luigi M. Romito ◽  
Alberto Mazzoni
Keyword(s):  
Firing Rate ◽  
Tourette Syndrome ◽  
Subthalamic Nucleus ◽  
Neural Activity ◽  
Single Neuron ◽  
Temporal Structure ◽  
Single Units ◽  
List Type ◽  
First Time ◽  
Bursting Activity

AbstractBasal ganglia dysfunctions have been suggested to play a causal role in the pathophysiology of most motor and non-motor symptoms of movement disorders as Tourette Syndrome (TS) or Parkinson’s Disease (PD). Intra/post-operative recordings from the subthalamic nucleus (STN) during Deep Brain Stimulation (DBS) procedures in PD patients have highlighted specific pathological patterns of neural activity. Spatial and temporal patterns of STN neural activity in TS are still unknown due to the lack of direct microrecordings in humans. Here, we describe for the first time specific neural activities of sensorimotor STN in TS patients, as recorded during intraoperative microrecordings. We analyzed 125 single units at 0.5 mm-spaced depths from the STN of anesthetized TS patients and we observed a large fraction of units (39/125, 31.2%) intensely bursting in the delta band (<4 Hz). In anesthetized PD patients we found similar average firing rate and spectral density of STN units, but differently to TS patients, only 4/54 (7.4%) of the units displayed bursting. Remarkably, bursting units in TS STN were not homogeneously distributed over the dorso-ventral trajectory of the recording: the highest density of bursting units was reliably found at the depth for which the clinical effect was maximal. Our results provide an unprecedented characterization of STN functional architecture and single units dynamics in TS patients, paving the way to an understanding of the role of STN subterritories in TS.Key PointsSingle neuron activity in Subthalamic Nucleus (STN) of patients with Tourette Syndrome (TS) was analyzed for the first time in literature.Firing rate and spectral content of single STN neurons in TS patients were found to be similar to those of anesthetized PD patients, while the analysis of arrhythmic bursting activity revealed that in TS patients the STN is characterized by a larger fraction of bursting neurons and more intense burstsBursting activity in TS was widespread across the whole STN, but with a higher density at the optimal lead location depth for DBS

scholarly journals Automated long-term recording and analysis of neural activity in behaving animals

2015 ◽  
Author(s):  
Ashesh K. Dhawale ◽  
Rajesh Poddar ◽  
Evi Kopelowitz ◽  
Valentin Normand ◽  
Steffen B. E. Wolff ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Unit Activity ◽  
Neural Activity ◽  
Single Unit ◽  
Single Units ◽  
Neural Dynamics ◽  
Single Unit Activity ◽  
Freely Moving ◽  
And Behavior

SummaryAddressing how neural circuits underlie behavior is routinely done by measuring electrical activity from single neurons during experimental sessions. While such recordings yield snapshots of neural dynamics during specified tasks, they are ill-suited for tracking single-unit activity over longer timescales relevant for most developmental and learning processes, or for capturing neural dynamics across different behavioral states. Here we describe an automated platform for continuous long-term recordings of neural activity and behavior in freely moving animals. An unsupervised algorithm identifies and tracks the activity of single units over weeks of recording, dramatically simplifying the analysis of large datasets. Months-long recordings from motor cortex and striatum made and analyzed with our system revealed remarkable stability in basic neuronal properties, such as firing rates and inter-spike interval distributions. Interneuronal correlations and the representation of different movements and behaviors were similarly stable. This establishes the feasibility of high-throughput long-term extracellular recordings in behaving animals.HighlightsWe record neural activity and behavior in rodents continuously (24/7) over monthsAn automated spike-sorting method isolates and tracks single units over many weeksNeural dynamics and motor representations are highly stable over long timescalesNeurons cluster into functional groups based on their activity in different stateseTOC BlurbDhawale et al. describe experimental infrastructure for recording neural activity and behavior continuously over months in freely moving rodents. A fully automated spike-sorting algorithm allows single units to be tracked over weeks of recording. Recordings from motor cortex and striatum revealed a remarkable long-term stability in both single unit activity and network dynamics.

Controlled exposure of female rhesus monkeys to 2,3,7,8-TCDD: Concentrations of TCDD in fat of offspring, and its decline over time

Chemosphere ◽  
1990 ◽  
Vol 20 (7-9) ◽  
pp. 1199-1202 ◽  
Author(s):  
R.E. Bowman ◽  
H.Y. Tong ◽  
M.L. Gross ◽  
S.J. Monson ◽  
N.C.A. Weerasinghe
Keyword(s):  
Rhesus Monkeys ◽  
Female Rhesus ◽  
Controlled Exposure ◽  
Over Time

Periodicity coding in the inferior colliculus of the cat. I. Neuronal mechanisms

1988 ◽  
Vol 60 (6) ◽  
pp. 1799-1822 ◽  
Author(s):  
G. Langner ◽  
C. E. Schreiner
Keyword(s):  
Firing Rate ◽  
Inferior Colliculus ◽  
Amplitude Modulation ◽  
Transfer Functions ◽  
Modulation Frequency ◽  
Temporal Structure ◽  
Stimulus Frequency ◽  
Single Units ◽  
Central Nucleus ◽  
Multiple Unit

1. Temporal properties of single- and multiple-unit responses were investigated in the inferior colliculus (IC) of the barbiturate-anesthetized cat. Approximately 95% of recording sites were located in the central nucleus of the inferior colliculus (ICC). Responses to contralateral stimulation with tone bursts and amplitude-modulated tones (100% sinusoidal modulation) were recorded. Five response parameters were determined for neurons at each location: 1) characteristic frequency (CF); 2) onset latency of responses to CF-tones 60 dB above threshold; 3) Q10 dB (CF divided by bandwidth of tuning curve 10 dB above threshold); 4) best modulation frequency for firing rate (rBMF or BMF; amplitude modulation frequency that elicited the highest firing rate); and 5) best modulation frequency for synchronization (sBMF; amplitude modulation frequency that elicited the highest degree of phase-locking to the modulation frequency). 2. Response characteristics for single units and multiple units corresponded closely. A BMF was obtained at almost all recording sites. For units with a similar CF, a range of BMFs was observed. The upper limit of BMF increased approximately proportional to CF/4 up to BMFs as high as 1 kHz. The lower limit of encountered BMFs for a given CF also increased slightly with CF. BMF ranges for single-unit and multiple-unit responses were similar. Twenty-three percent of the responses revealed rBMFs between 10 and 30 Hz, 51% between 30 and 100 Hz, 18% between 100 and 300 Hz, and 8% between 300 and 1000 Hz. 3. For single units with modulation transfer functions of bandpass characteristics, BMFs determined for firing rate and synchronization were similar (r2 = 0.95). 4. Onset latencies for responses to CF tones 60 dB above threshold varied between 4 and 120 ms. Ninety percent of the onset latencies were between 5 and 18 ms. A range of onset latencies was recorded for different neurons with any given CF. The onset response latency of a given unit or unit cluster was significantly correlated with the period of the BMF and the period of the CF (P less than 0.05). 5."Intrinsic oscillations" of short duration, i.e., regularly timed discharges of units in response to stimuli without a corresponding temporal structure, were frequently observed in the ICC. Oscillation intervals were commonly found to be integer multiples of 0.4 ms. Changes of stimulus frequency or intensity had only minor influences on these intrinsic oscillations.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Neurons in the mouse brain correlate with cryptocurrency price: a cautionary tale

2021 ◽  
Author(s):  
Guido Meijer
Keyword(s):  
Firing Rate ◽  
False Positive ◽  
False Positive Rate ◽  
Multiple Comparisons ◽  
Single Neurons ◽  
Bonferroni Correction ◽  
Cautionary Tale ◽  
Neural Correlate ◽  
Positive Rate ◽  
Over Time

In this paper I report the discovery of neurons which showed a neural correlate with ongoing fluctuations of Bitcoin and Ethereum prices at the time of the recording. I used the publicly available dataset of Neuropixel recordings by the Allen Institute to correlate the firing rate of single neurons with cryptocurrency price. Out of ~40.000 recorded single neurons, ~70% showed a significant correlation with Bitcoin or Ethereum prices. Even when using the conservative Bonferroni correction for multiple comparisons, ~35% of neurons showed a significant correlation, which is well above the expected false positive rate of 5%. These results were due to "nonsense correlations": when correlating two signals which both evolve slowly over time, the chances of finding a significant correlation between the two are much higher than when comparing signals which lack this property.

Neuronal Clusters in the Primate Motor Cortex during Interceptin of Moving Targets.

2001 ◽  
Vol 13 (3) ◽  
pp. 319-331 ◽  
Author(s):  
Daeyeol Lee ◽  
Nicholas L. Port ◽  
Wolfgang Kruse ◽  
Apostolos P. Georgopoulos
Keyword(s):  
Motor Cortex ◽  
Rhesus Monkeys ◽  
Primary Motor Cortex ◽  
Human Subjects ◽  
Cell Activity ◽  
Target Velocity ◽  
Behavioral Strategies ◽  
Additional Information ◽  
Single Cell Activity ◽  
Initial Target

Two rhesus monkeys were trained to intercept a moving target at a fixed location with a feedback cursor controlled bya 2-D manipulandum. The direction from which the target appeared, the time from the target onset to its arrival at the interception point, and the target acceleration were randomized for each trial, thus requiring the animal to adjust its movement according to the visual input on a trail-by-trail basis. The two animals adopted different strategies, similar to those identified previously in human subjects. Single-cell activity was recorded from the arm area of the primary motor cortex in these two animals, and the neurons were classified based on the temporal patterns in their activity, using a nonhierarchical cluster analysis. Results of this analysis revealed differences in the complexity and diversity of motor cortical activity between the two animals that paralleled those of behavioral strategies. Most clusters displayed activity closedly related to the kinematics of hand movements. In addition, some clusters displayed patterns of activation that conveyed additional information necessary for successful performance of the task, such as the initial target velocity and the interval between successive submovements, suggesting that such information is represented in selective subpopulations of neurons in the primary motor cortex. These results also suggest that conversion of information about target motion into movement-related signals takes place in a broad network of cortical areas including the primary motor cortex.

Vesicoureteral Reflux in the Primate: II. Maturation of the Ureterovesical Junction

PEDIATRICS ◽  
1977 ◽  
Vol 59 (4) ◽  
pp. 566-568
Author(s):  
James A. Roberts ◽  
Arthur J. Riopelle
Keyword(s):  
Birth Weight ◽  
Vesicoureteral Reflux ◽  
Rhesus Monkeys ◽  
Skeletal Maturity ◽  
Protein Deficiency ◽  
Ureterovesical Junction ◽  
Infant Rhesus ◽  
Over Time

Infant rhesus monkeys frequently show vesicoureteral reflux unlike adults. We studied monkeys born of mothers who had been on normal or protein-deficient diets. Protein deficiency may influence the time that reflux continues, but this was not statistically proved. Reflux disappears over time. The time was influenced by when the pregnancy was initiated and the maturity of the infant. Maturation as measured by skeletal maturity scores correlated well with the time of reflux, but growth as measured by birth weight did not. Vesicoureteral reflux in the monkey is frequent, but maturation of the ureterovesical junction occurs by age 3 years and reflux disappears.

scholarly journals Local Cerebral Blood Flow Measured by Xenon-Enhanced CT during Cryogenic Brain Edema and Intracranial Hypertension in Monkeys

1993 ◽  
Vol 13 (5) ◽  
pp. 763-772 ◽  
Author(s):  
Joseph M. Darby ◽  
Edwin M. Nemoto ◽  
Howard Yonas ◽  
Liping Yao ◽  
John A. Melick ◽  
...  
Keyword(s):  
Blood Flow ◽  
Brain Edema ◽  
Rhesus Monkeys ◽  
Vasogenic Edema ◽  
Ct Scans ◽  
Local Cerebral Blood Flow ◽  
Skull Model ◽  
Enhanced Ct ◽  
Enhanced Computed Tomography ◽  
Over Time

We developed a closed-skull model of freeze injury-induced brain edema, a model classically thought to produce vasogenic edema, and observed the natural course of changes in edema and blood flow using xenon-enhanced computed tomography (CT) in five rhesus monkeys before and for up to 6 h post insult. Intracranial pressure (ICP) gradually rose throughout the duration of the experiment. CT scans and CBF images permitted direct observation of the evolution of the lesion and revealed early ischemia in the periphery of the injury zone that progressed over time in association with edema. Frequency histogram analysis of local CBF (lCBF) demonstrated subtle but potentially important changes in distribution of lCBF between and within hemispheres at various times post insult. Changes in lCBF distribution were phasic and dissociated from increases in ICP in the latter stages of injury. The Xe/CT CBF method can be used to evaluate the effects of injury and therapy on CBF in this and other models of acute brain injury.

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