Properties of delay-period neuronal activity in the primate prefrontal cortex during memory- and sensory-guided saccade tasks

2004 ◽  
Vol 19 (2) ◽  
pp. 447-457 ◽  
Author(s):  
Satoshi Tsujimoto ◽  
Toshiyuki Sawaguchi
1990 ◽  
Vol 63 (6) ◽  
pp. 1385-1400 ◽  
Author(s):  
T. Sawaguchi ◽  
M. Matsumura ◽  
K. Kubota

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)


1998 ◽  
Vol 79 (6) ◽  
pp. 2919-2940 ◽  
Author(s):  
Matthew V. Chafee ◽  
Patricia S. Goldman-Rakic

Chafee, Matthew V. and Patricia S. Goldman-Rakic. Matching patterns of activity in primate prefrontal area 8a and parietal area 7ip neurons during a spatial working memory task. J. Neurophysiol. 79: 2919–2940, 1998. Single-unit recording studies of posterior parietal neurons have indicated a similarity of neuronal activation to that observed in the dorsolateral prefrontal cortex in relation to performance of delayed saccade tasks. A key issue addressed in the present study is whether the different classes of neuronal activity observed in these tasks are encountered more frequently in one or the other area or otherwise exhibit region-specific properties. The present study is the first to directly compare these patterns of neuronal activity by alternately recording from parietal area 7ip and prefrontal area 8a, under the identical behavioral conditions, within the same hemisphere of two monkeys performing an oculomotor delayed response task. The firing rate of 222 posterior parietal and 235 prefrontal neurons significantly changed during the cue, delay, and/or saccade periods of the task. Neuronal responses in the two areas could be distinguished only by subtle differences in their incidence and timing. Thus neurons responding to the cue appeared earliest and were more frequent among the task-related neurons within parietal cortex, whereas neurons exhibiting delay-period activity accounted for a larger proportion of task-related neurons in prefrontal cortex. Otherwise, the task-related neuronal activities were remarkably similar. Cue period activity in prefrontal and parietal cortex exhibited comparable spatial tuning and temporal duration characteristics, taking the form of phasic, tonic, or combined phasic/tonic excitation in both cortical populations. Neurons in both cortical areas exhibited sustained activity during the delay period with nearly identical spatial tuning. The various patterns of delay-period activity—tonic, increasing or decreasing, alone or in combination with greater activation during cue and/or saccade periods—likewise were distributed to both cortical areas. Finally, similarities in the two populations extended to the proportion and spatial tuning of presaccadic and postsaccadic neuronal activity occurring in relation to the memory-guided saccade. The present findings support and extend evidence for a faithful duplication of receptive field properties and virtually every other dimension of task-related activity observed when parietal and prefrontal cortex are recruited to a common task. This striking similarity attests to the principal that information shared by a prefrontal region and a sensory association area with which it is connected is domain specific and not subject to hierarchical elaboration, as is evident at earlier stages of visuospatial processing.


1999 ◽  
Vol 126 (3) ◽  
pp. 315-335 ◽  
Author(s):  
Ilsun M. White ◽  
S. P. Wise

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Luca F. Kaiser ◽  
Theo O. J. Gruendler ◽  
Oliver Speck ◽  
Lennart Luettgau ◽  
Gerhard Jocham

AbstractIn a dynamic world, it is essential to decide when to leave an exploited resource. Such patch-leaving decisions involve balancing the cost of moving against the gain expected from the alternative patch. This contrasts with value-guided decisions that typically involve maximizing reward by selecting the current best option. Patterns of neuronal activity pertaining to patch-leaving decisions have been reported in dorsal anterior cingulate cortex (dACC), whereas competition via mutual inhibition in ventromedial prefrontal cortex (vmPFC) is thought to underlie value-guided choice. Here, we show that the balance between cortical excitation and inhibition (E/I balance), measured by the ratio of GABA and glutamate concentrations, plays a dissociable role for the two kinds of decisions. Patch-leaving decision behaviour relates to E/I balance in dACC. In contrast, value-guided decision-making relates to E/I balance in vmPFC. These results support mechanistic accounts of value-guided choice and provide evidence for a role of dACC E/I balance in patch-leaving decisions.


1997 ◽  
Vol 78 (1) ◽  
pp. 450-460 ◽  
Author(s):  
Peter Svensson ◽  
Satoshi Minoshima ◽  
Ahmad Beydoun ◽  
Thomas J. Morrow ◽  
Kenneth L. Casey

Svensson, Peter, Satoshi Minoshima, Ahmad Beydoun, Thomas J. Morrow, and Kenneth L. Casey. Cerebral processing of acute skin and muscle pain in humans. J. Neurophysiol. 78: 450–460, 1997. The human cerebral processing of noxious input from skin and muscle was compared with the use of positron emission tomography with intravenous H2 15O to detect changes in regional cerebral blood flow (rCBF) as an indicator of neuronal activity. During each of eight scans, 11 normal subjects rated the intensity of stimuli delivered to the nondominant (left) forearm on a scale ranging from 0 to 100 with 70 as pain threshold. Cutaneous pain was produced with a high-energy CO2 laser stimulator. Muscle pain was elicited with high-intensity intramuscular electrical stimulation. The mean ratings of perceived intensity for innocuous and noxious stimulation were32.6 ± 4.5 (SE) and 78.4 ± 1.7 for cutaneous stimulation and 15.4 ± 4.2 and 73.5 ± 1.4 for intramuscular stimulation. The pain intensity ratings and the differences between noxious and innocuous ratings were similar for cutaneous and intramuscular stimuli ( P > 0.05). After stereotactic registration, statistical pixel-by-pixel summation ( Z score) and volumes-of-interest (VOI) analyses of subtraction images were performed. Significant increases in rCBF to both noxious cutaneous and intramuscular stimulation were found in the contralateral secondary somatosensory cortex (SII) and inferior parietal lobule [Brodmann area (BA) 40]. Comparable levels of rCBF increase were found in the contralateral anterior insular cortex, thalamus, and ipsilateral cerebellum. Noxious cutaneous stimulation caused significant activation in the contralateral lateral prefrontal cortex (BA 10/46) and ipsilateral premotor cortex (BA 4/6). Noxious intramuscular stimulation evoked rCBF increases in the contralateral anterior cingulate cortex (BA 24) and subsignificant responses in the contralateral primary sensorimotor cortex (MI/SI) and lenticular nucleus. These activated cerebral structures may represent those recruited early in nociceptive processing because both forms of stimuli were near pain threshold. Correlation analyses showed a negative relationship between changes in rCBF for thalamus and MI/SI for cutaneous stimulation, and positive relationships between thalamus and anterior insula for both stimulus modalities. Direct statistical comparisons between innocuous cutaneous and intramuscular stimulation with the use of Z scores and VOI analyses showed no reliable differences between these two forms of noxious stimulation, indicating a substantial overlap in brain activation pattern. The comparison of noxious cutaneous and intramuscular stimulation indicated more activation in the premotor cortex, SII, and prefrontal cortex with cutaneous stimulation, but these differences did not reach statistical significance. The similar cerebral activation patterns suggest that the perceived differences between acute skin and muscle pain are mediated by differences in the intensity and temporospatial pattern of neuronal activity within similar sets of forebrain structures.


2008 ◽  
Vol 100 (1) ◽  
pp. 520-525 ◽  
Author(s):  
Nandakumar S. Narayanan ◽  
Mark Laubach

Rats with impaired function in dorsomedial regions of the prefrontal cortex (dmPFC) are unable to maintain a behavioral response over a delay period. Here we report that neurons in this cortical region are prominently modulated after errors in a tone-cued, simple reaction time task and that inactivation of dmPFC attenuates a slowing of reaction times that is observed following errors. Using methods for chronic single-unit recording, we found that approximately one-third of dmPFC neurons were modulated after errors, and 28% of these neurons had increased posterror firing that persisted into the delay period of the following trial. In contrast to dmPFC, no such neurons were found in motor cortex. Our results implicate the dorsomedial prefrontal cortex in a form of retrospective working memory that improves task performance following errors.


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