Comparison of neuronal firing rates in somatosensory and posterior parietal cortex during prehension

被引:38
作者
Debowy, DJ
Ghosh, S
Ro, JY
Gardner, EP
机构
[1] NYU, Sch Med, Dept Physiol & Neurosci, New York, NY 10016 USA
[2] Univ Western Australia, Ctr Neuromuscular & Neurol Disorders, Nedlands, WA 6009, Australia
[3] Curtin Univ, Sch Physiotherapy, Perth, WA 6009, Australia
[4] Univ Maryland, Sch Dent, Dept Oral & Craniofacial Biol Sci, Baltimore, MD 21201 USA
关键词
hand movements; prehension; somatosensory system; parietal cortex; touch; motor control;
D O I
10.1007/s002210000660
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
To evaluate their functional roles during prehension, single-unit recordings were made in the hand area of primary somatosensory areas 3b, 1 and 2 (S-I) and posterior parietal areas 5 and 7 (PPC) of the same animal. Response profiles of mean firing rate during performance of a multistage reach, grasp, and lift task were analyzed to determine the period(s) of peak firing and to measure statistically significant rises or falls in rate compared with baseline. We used the peak firing stage(s) to subdivide the population into classes tuned to single actions or two successive stages, or into multiaction groups that had sustained facilitation (BT) or inhibition (GI) during hand-object interactions. Four times as many neurons fired at peak rates during acquisition stages (approach, contact, grasp) than upon release, and their firing rates were higher. Grasping evoked the strongest responses, as grasp-tuned neurons had the highest peak rates in the population; BT, contact-grasp, and grasp-lift cells also fired maximally in the grasp stage. Grasping also coincided with maximal inhibition of GI cells, as well as of neurons tuned to approach or relaxation of grasp. Holding evoked the lowest meant rates, and had the fewest tuned cells. S-I and PPC showed significant differences in behaviors evoking peak firing as well as facilitation and inhibition; these correlated with input modalities in each area. Hand contact with the object and positioning of the fingers for grasp was the most strongly represented behavior in anterior S-I, where 61% received tactile inputs from glabrous skin. Nearly 60% were facil itated at contact, 38% fired at peak rates, and 10% were inhibited; release of grasp evoked peak firing in only 5% of 3b-1 neurons. In posterior S-I, where proportions of tactile and deep inputs were similar, positioning and grasping elicited peak responses in 38% and 31%, respectively; 80% were facilitated or inhibited during grasping. During lift and hold, inhibition rose to 43%, while excitation declined under 10%. PPC had the highest proportions firing at peak rates during hand preshaping before contact (28%) and had the most facilitated responses (38%) in this stage. Only 10% fired at peak rates during grasping. During later manipulatory actions, proportions of facilitated and inhibited responses in PPC were similar to those in posterior S-I. The data support models in which PPC plans hand movements during prehension rather than guiding their execution. Sensory monitoring of hand-object interaction occurs in S-I, where cells sense specific hand behaviors, signal stage completion, enable error correction, and may update grasp programs formulated in PPC. The results are discussed in relation to those obtained from lesion studies in humans.
引用
收藏
页码:269 / 291
页数:23
相关论文
共 61 条
[1]   Multimodal representation of space in the posterior parietal cortex and its use in planning movements [J].
Andersen, RA ;
Snyder, LH ;
Bradley, DC ;
Xing, J .
ANNUAL REVIEW OF NEUROSCIENCE, 1997, 20 :303-330
[2]  
Andersen RA, 1998, NOVART FDN SYMP, V218, P109
[3]   Human anterior intraparietal area subserves prehension - A combined lesion and functional MRI activation study [J].
Binkofski, F ;
Dohle, C ;
Posse, S ;
Stephan, KM ;
Hefter, H ;
Seitz, RJ ;
Freund, HJ .
NEUROLOGY, 1998, 50 (05) :1253-1259
[4]   A parieto-premotor network for object manipulation: evidence from neuroimaging [J].
Binkofski, F ;
Buccino, G ;
Stephan, KM ;
Rizzolatti, G ;
Seitz, RJ ;
Freund, HJ .
EXPERIMENTAL BRAIN RESEARCH, 1999, 128 (1-2) :210-213
[5]   The effects of muscimol inactivation of small regions of motor and somatosensory cortex on independent finger movements and force control in the precision grip [J].
Brochier, T ;
Boudreau, MJ ;
Paré, M ;
Smith, AM .
EXPERIMENTAL BRAIN RESEARCH, 1999, 128 (1-2) :31-40
[6]   Friction, not texture, dictates grip forces used during object manipulation [J].
Cadoret, G ;
Smith, AM .
JOURNAL OF NEUROPHYSIOLOGY, 1996, 75 (05) :1963-1969
[7]  
CHAPMAN CE, 1991, EXP BRAIN RES, V87, P319
[8]   Space and attention in parietal cortex [J].
Colby, CL ;
Goldberg, ME .
ANNUAL REVIEW OF NEUROSCIENCE, 1999, 22 :319-349
[9]  
Debowy D., 1998, Society for Neuroscience Abstracts, V24, P1127
[10]  
DEBOWY D, 2000, SOC NEUR ABSTR, V25, P2195