scholarly journals Representation of Immediate and Final Behavioral Goals in the Monkey Prefrontal Cortex during an Instructed Delay Period

2005 ◽  
Vol 15 (10) ◽  
pp. 1535-1546 ◽  
Author(s):  
Naohiro Saito ◽  
Hajime Mushiake ◽  
Kazuhiro Sakamoto ◽  
Yasuto Itoyama ◽  
Jun Tanji
Keyword(s):  
Prefrontal Cortex ◽  
Delay Period ◽  
Monkey Prefrontal Cortex

Catecholaminergic effects on neuronal activity related to a delayed response task in monkey prefrontal cortex

1990 ◽  
Vol 63 (6) ◽  
pp. 1385-1400 ◽  
Author(s):  
T. Sawaguchi ◽  
M. Matsumura ◽  
K. Kubota
Keyword(s):  
Prefrontal Cortex ◽  
Neuronal Activity ◽  
Background Activity ◽  
Japanese Macaque ◽  
Central Zone ◽  
Delay Period ◽  
Delayed Response ◽  
Differential Delay ◽  
Hold Period ◽  
Monkey Prefrontal Cortex

1. Using iontophoretic techniques, we investigated the effects of dopamine (DA) and noradrenaline (NA) on neuronal activity related to a delayed response (DR) task in the prefrontal cortex (PFC) of the Japanese macaque monkeys. The DR task was initiated by rotation of a handle to a central zone and consisted of seven distinct time periods: an initial waiting period of 0.3 s, a precue period of 1 s (a central green lamp), a cue period of 1 s (left or right lamp), a delay period of 4 s, a go period of 1 s (red lamp in the center; rotation of the handle to either the left or right zone), a hold period (holding of the handle in either the left or right zone for 0.3 s), and a final reward period. 2. A total of 116 neurons were DR task related. They showed increases in activity during the precue period (Precue-types, n = 19), during both the cue and go periods (Cue/GO-types, n = 17), the go period (GO-types, n = 16), and during the delay period (Delay-types, n = 64). The Delay-type neurons were further divided into differential neurons (n = 33), for which the magnitude of the delay-related activity differed significantly between left- and right-cue trials, and nondifferential neurons (n = 31). Some of the Delay-type neurons also showed increases in activity during the cue (n = 26), go (n = 27), or both the cue and go periods (n = 11). 3. DA or NA, applied iontophoretically with a current of 50 nA, induced increased or decreased responses in most of the DR task-related neurons. DA increased activity of most of the Cue/GO-(16/17), GO-(13/16), and Delay-type neurons (49/64), and NA decreased activity of most of the Precue- (13/19) and non-differential Delay-type neurons (25/31). Thus different types of DR task-related neurons showed different responses to DA and NA. 4. In Cue/GO-, GO-, and/or Delay-type neurons, DA increased the activity related to the cue, go, and delay periods more strongly than it increased background activity. As a result, the ratio [i.e., signal-to-noise (S/N) ratio] of activity related to the cue, go, and delay periods to background activity was increased. 5. In Precue-type or nondifferential Delay-type neurons, NA decreased background activity more strongly than it decreased activity during the precue or delay period.(ABSTRACT TRUNCATED AT 400 WORDS)

Dissociation of Mnemonic Coding and Other Functional Neuronal Processing in the Monkey Prefrontal Cortex

1997 ◽  
Vol 77 (2) ◽  
pp. 761-774 ◽  
Author(s):  
Synnöve Carlson ◽  
Pia Rämä ◽  
Heikki Tanila ◽  
Ilkka Linnankoski ◽  
Heikki Mansikka
Keyword(s):  
Prefrontal Cortex ◽  
Eye Movements ◽  
Task Performance ◽  
Single Neuron ◽  
Sensory Stimulation ◽  
Delay Period ◽  
Visual Fixation ◽  
Task Context ◽  
Neuronal Processing ◽  
Monkey Prefrontal Cortex

Carlson, Synnöve, Pia Rämä, Heikki Tanila, Ilkka Linnankoski, and Heikki Mansikka. Dissociation of mnemonic coding and other functional neuronal processing in the monkey prefrontal cortex. J. Neurophysiol. 77: 761–774, 1997. Single-neuron activity was recorded in the prefrontal cortex of three monkeys during the performance of a spatial delayed alternation (DA) task and during the presentation of a variety of visual, auditory, and somatosensory stimuli. The aim was to study the relationship between mnemonic neuronal processing and other functional neuronal responsiveness at the single-neuron level in the prefrontal cortex. Recordings were performed in both experimental situations from 152 neurons. The majority of the neurons (92%) was recorded in the prefrontal cortex. Nine of the neurons were recorded in the dorsal bank of the anterior cingulate sulcus and two in the premotor cortex. Of the total number of neurons recorded in the prefrontal area, 32% fired in relation to the DA task performance and 39% were responsive to sensory stimulation or to the movements of the monkey outside of the memory task context. Altogether 42% of the recorded neurons were neither activated by the various stimuli nor by the DA task performance. Three types of task-related neuronal activity were recorded: delay related, delay and movement related, and movement related. The majority of the task-related neurons ( n = 33, 73%) fired in relation to the delay period. Of the delay-related neurons, 26 (79%) were spatially selective. The number of spatially selective delay-related neurons of the whole population of recorded neurons was 18%. Twelve task-related neurons (27%) fired in relation to the response period of the DA task. Five of these neurons changed their firing rate during the delay period and were classified as delay/movement-related neurons. Contrary to the delay-related neurons, less than half (42%) of the response-related neurons were spatially selective. The majority (70%) of the delay-related neurons could not be activated by any of the sensory stimuli used and did not fire in relation to the movements of the monkey. The remaining portion of the delay-related neurons was activated by stationary and moving visual stimuli or by visual fixation of an object. In contrast to the delay-related neurons, the majority (66%) of the task-related neurons firing in relation to the movement period were also responsive to sensory stimulation outside of the task context. The majority of these neurons responded to visual stimulation, visual fixation of an object, or tracking eye movements. One neuron gave a somatomotor and another a polysensory response. The majority ( n = 37, 67%) of all neurons responding to stimulation outside of the task context did not fire in relation to the DA task performance. The majority of their responses was elicited by visual stimuli or was related to visual fixation of an object or to eye movements. Only six neurons fired in relation to auditory, somatosensory, or somatomotor stimulation. This study provides further evidence about the significance of the dorsolateral prefrontal cortex in spatial working memory processing. Although a considerable number of all DA task-related neurons responded to visual, somatosensory, and auditory stimulation or to the movements of the monkey, most delay-related neurons engaged in the spatial DA task did not respond to extrinsic sensory stimulation. These results indicate that most prefrontal neurons firing selectively during the delay phase of the DA task are highly specialized and process only task-related information.

Neural Activity in Monkey Prefrontal Cortex Is Modulated by Task Context and Behavioral Instruction during Delayed-match-to-sample and Conditional Prosaccade—Antisaccade Tasks

2006 ◽  
Vol 18 (5) ◽  
pp. 749-765 ◽  
Author(s):  
Kevin Johnston ◽  
Stefan Everling
Keyword(s):  
Prefrontal Cortex ◽  
Delay Period ◽  
Neural Representation ◽  
Task Context ◽  
Match To Sample ◽  
Stimulus Response ◽  
Visuomotor Task ◽  
Test Picture ◽  
Monkey Prefrontal Cortex ◽  
Behavioral Instruction

Complex behavior often requires the formation of associations between environmental stimuli and motor responses appropriate to those stimuli. Moreover, the appropriate response to a given stimulus may vary depending on environmental context. Stimulus-response associations that are adaptive in one situation may not be in another. The prefrontal cortex (PFC) has been shown to be critical for stimulus-response mapping and the implementation of task context. To investigate the neural representation of sensory-motor associations and task context in the PFC, we recorded the activity of prefrontal neurons in two monkeys while they performed two tasks. The first task was a delayed-match-to-sample task in which monkeys were presented with a sample picture and rewarded for making a saccade to the test picture that matched the sample picture following a delay period. The second task was a conditional visuomotor task in which identical sample pictures were presented. In this task, animals were rewarded for performing either prosaccades or antisaccades following the delay period depending on sample picture identity. PFC neurons showed task selectivity, object selectivity, and combinations of task and object selectivity. These modulations of activity took the form of a reduction in stimulus and delay-related activity, and a pro/anti instruction-based grouping of delay activity in the conditional visuomotor task. These data show that activity in PFC neurons is modulated by experimental context, and that this activity represents the formal demands of the task currently being performed.

scholarly journals Postnatal development of synaptic structure proteins in pyramidal neuron axon initial segments in monkey prefrontal cortex

2009 ◽  
Vol 514 (4) ◽  
pp. 353-367 ◽  
Author(s):  
Dianne A. Cruz ◽  
Emily M. Lovallo ◽  
Steven Stockton ◽  
Matthew Rasband ◽  
David A. Lewis
Keyword(s):  
Prefrontal Cortex ◽  
Postnatal Development ◽  
Pyramidal Neuron ◽  
Synaptic Structure ◽  
Monkey Prefrontal Cortex ◽  
Axon Initial Segments

scholarly journals Functional properties of GABA synaptic inputs onto GABA neurons in monkey prefrontal cortex

2015 ◽  
Vol 113 (6) ◽  
pp. 1850-1861 ◽  
Author(s):  
Diana C. Rotaru ◽  
Cameron Olezene ◽  
Takeaki Miyamae ◽  
Nadezhda V. Povysheva ◽  
Aleksey V. Zaitsev ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Input Resistance ◽  
Synaptic Inputs ◽  
Gaba Neurons ◽  
Decay Times ◽  
Cortical Interneurons ◽  
Dorsolateral Prefrontal ◽  
Gaba Neuron ◽  
Fast Spiking ◽  
Monkey Prefrontal Cortex

In rodent cortex GABAA receptor (GABAAR)-mediated synapses are a significant source of input onto GABA neurons, and the properties of these inputs vary among GABA neuron subtypes that differ in molecular markers and firing patterns. Some features of cortical interneurons are different between rodents and primates, but it is not known whether inhibition of GABA neurons is prominent in the primate cortex and, if so, whether these inputs show heterogeneity across GABA neuron subtypes. We thus studied GABAAR-mediated miniature synaptic events in GABAergic interneurons in layer 3 of monkey dorsolateral prefrontal cortex (DLPFC). Interneurons were identified on the basis of their firing pattern as fast spiking (FS), regular spiking (RS), burst spiking (BS), or irregular spiking (IS). Miniature synaptic events were common in all of the recorded interneurons, and the frequency of these events was highest in FS neurons. The amplitude and kinetics of miniature inhibitory postsynaptic potentials (mIPSPs) also differed between DLPFC interneuron subtypes in a manner correlated with their input resistance and membrane time constant. FS neurons had the fastest mIPSP decay times and the strongest effects of the GABAAR modulator zolpidem, suggesting that the distinctive properties of inhibitory synaptic inputs onto FS cells are in part conferred by GABAARs containing α1 subunits. Moreover, mIPSCs differed between FS and RS interneurons in a manner consistent with the mIPSP findings. These results show that in the monkey DLPFC GABAAR-mediated synaptic inputs are prominent in layer 3 interneurons and may differentially regulate the activity of different interneuron subtypes.

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