1. Activity of up to 10 single units was recorded in parallel from frontal areas behaving monkeys. 2. Spatiotemporal firing patterns were revealed by a method that detects all excessively repeating regardless their complexity or single-unit composition. 3. Excess found 30-60% the cases examined when timing jitter 1-3 ms allowed. 4. An independent test refuted hypothesis these represented chance events. 5. In given behavioral condition there usually many different patterns, each several...

To investigate the role of basal ganglia in parkinsonian tremor, we recorded hand tremor and simultaneous activity several neurons external internal segments globus pallidus (GPe GPi) two vervet monkeys, before after systemic treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) development parkinsonism 5 11 Hz. In healthy only 11% (20/174) GPe cells 3% (1/29) GPi displayed significant 3–19 Hz oscillations. After MPTP treatment, 39% (107/271) 43% (26/61) developed Oscillation...

It has not been possible to analyze the cellular mechanisms underlying learning in behaving mammals because of difficulties recording intracellularly from awake animals. Therefore, present study neuronal plasticity monkeys, net effect a single neuron on another (the "functional connection") was evaluated by cross-correlating times firing two neurons. When neurons were induced fire together within short time window, functional connection between them potentiated, and when simultaneous...

Recent studies showed that the low-frequency component of local field potentials (LFPs) in monkey motor cortex carries information about parameters voluntary arm movements. Here, we studied how different signal components LFP time and frequency domains are modulated during center-out Analysis LFPs domain amplitude a slow complex waveform beginning shortly before onset movement is with direction movement. Examining domain, found direction-dependent modulations occur three ranges, which...

Parallel recordings of spike trains several single cortical neurons in behaving monkeys were analyzed as a hidden Markov process. The parallel considered multivariate Poisson process whose vector firing rates change with time. As consequence this approach, the complete recording can be segmented into sequence few statistically discriminated states, dynamics are modeled first-order chain. biological validity and benefits approach examined independent ways: (i) statistical consistency...

Primary motor cortex (MI) neurons discharge vigorously during voluntary movement. A cardinal symptom of Parkinson's disease (PD) is poverty movement (akinesia). Current models PD thus hypothesize that increased inhibitory pallidal output reduces firing rates in frontal cortex, including MI, resulting akinesia and muscle rigidity. We recorded the simultaneous spontaneous several arm-related area MI two monkeys globus pallidus (GP) one two. Accelerometers were fastened to forelimbs detect...

Prut, Yifat, Eilon Vaadia, Hagai Bergman, Iris Haalman, Hamutal Slovin, and Moshe Abeles. Spatiotemporal structure of cortical activity: properties behavioral relevance. J. Neurophysiol. 79: 2857–2874, 1998. The study was designed to reveal occurrences precise firing sequences (PFSs) in activity test their Two monkeys were trained perform a delayed-response paradigm open puzzle boxes. Extracellular recorded from neurons premotor prefrontal areas with an array six microelectrodes. An...

Midbrain dopaminergic neurons (DANs) typically increase their discharge rate in response to appetitive predictive cues and outcomes, whereas striatal cholinergic tonically active interneurons (TANs) decrease rate. This may indicate that the activity of TANs DANs is negatively correlated can broaden basal ganglia reinforcement teaching signal, for instance by encoding worse than predicted events. We studied 106 180 two monkeys recorded during performance a classical conditioning task with...

1. Previous studies indicate that tonically active neurons (TANs) are the cholinergic interneurons of striatum and predict their activity is synchronized. To test whether TANs do fire synchronously, dopamine depletion affects synchronization, we recorded simultaneous several in putamens two vervet monkeys before after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment. 2. Cross-correlation analysis revealed most pairs TANS (33 54; 61.1%) synchronously at +/- 60-ms delay....

1. Neuronal mechanisms for decoding sound azimuth and angular movement were studied by recordings of several single units in parallel the core areas auditory cortex macaque monkey. The activity 180 was recorded during presentation moving static stimuli. Both interactions between neighboring neurons response to each stimulus analyzed. 2. Sixty-two percent showed significant modulation their firing rates as a function azimuth. Contralateral stimuli preferred majority (approximately 60%) these...

The goal of this study is to assess the function tonically active neurons (TANs) striatum and their malfunction in parkinsonian state. We recorded multiple spike trains striatal TANs pallidal neurons, which are main target projections. Recordings were performed two vervet monkeys before after induction tremulous parkinsonism by systemic injection 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP). then calculated cross-correlograms between evaluate interactions them. In normal...

Cortical local field potentials (LFPs) reflect synaptic and accordingly correlate with neuronal discharge. Because LFPs are coherent across substantial cortical areas, we hypothesized that spike correlations could be predicted from them. recorded in the basal ganglia (BG) also correlated discharge clinically accessible Parkinson's disease patients, were interested testing this hypothesis BG, as well. We unit multiple electrodes, which placed primary motor cortex or (striatum pallidum) of two...

The influence of sound localization behavior on unit activity in the frontal cortex awake rhesus monkeys was examined by comparing responses under three behavioral conditions: auditory localization, during which a response required to location (broad-band noise) source; detect, indicate occurrence regardless location; visual no sounds were presented and stimulus; nonperform, presentation stimuli as first two conditions, but with animal sitting passively. Extracellular microelectrode...

To test whether spiking activity of six to eight simultaneously recorded neurons in the frontal cortex a monkey can be characterized by sequence discrete and stable states, neuronal is analyzed hidden Markov model (HMM). Using HMM method, we are able detect distinct states within which firing rates approximately stationary. Transitions between as expressed concomitant changes several units, occur quite abruptly. The significance consistency confirmed comparison with simulated data. detected...

High-frequency stimulation of the globus pallidus (GP) has emerged as a successful tool for treating Parkinson's disease and other motor disorders. However, mechanism governing its therapeutic effect is still under debate. To shed light on basic deep brain (DBS), we performed microstimulation in GP 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated monkey while recording with microelectrodes same nucleus. We used robust methods to reduce stimulus artifact, 600-3000 repetitions single...