视觉编码的快速学习

活动依赖的神经可塑性在视觉皮层信息处理过程中起着很重要的作用。该文将讲述几个关于视觉刺激引起皮层反应发生快速变化的研究工作。在体膜片钳的实验结果表明,将视觉刺激与能够诱发孽个视皮层神经元发放动作电位的电刺激相偶联可以改变神经元的感受野特性。单电极和多电极胞外记录的实验结果显示,反复地给予自然图形电影刺激,不仅能增加视皮层神经元反应的可靠性,而且能造成之后的自发活动中存在“记忆的痕迹”。最后,用电压敏感染料成像的方法对群体细胞活动进行考察,结果提示视觉活动之后的皮层回放可能是由皮层波介导的。     

初级视皮层神经元非经典感受野研究的新进展

感觉皮层神经元的非经典感受野(简称"外周")对经典感受野(简称"中心")的调节作用广泛存在于哺乳动物中,被认为是感觉皮层神经元的基本特性.以初级视皮层神经元为例,刺激其外周能有效地调节刺激其中心引起的反应,这种作用主要是抑制性的.理解初级视皮层神经元的外周对中心的调节机制能够深入揭示哺乳动物的感觉皮层神经元信息处理的基本原则.本文综述了引起初级视皮层神经元非经典感受野对经典感受野调节作用的神经环路机制和计算模型研究的进展.     

弱背景噪声对大鼠听皮层神经元频率调谐的影响

在自然环境中,人和动物常在一定的背景噪声下感知信号声刺激,然而,关于低强度的弱背景噪声如何影响听皮层神经元对声刺激频率的编码尚不清楚.本研究以大鼠听皮层神经元的频率反应域为研究对象,测定了阈下背景噪声对79个神经元频率反应域的影响.结果表明,弱背景噪声对大鼠初级听皮层神经元的听反应既有抑制性影响、又有易化性影响.一般来说,抑制性影响使神经元的频率调谐范围和最佳频率反应域缩小,易化性影响使神经元的频率调谐范围和最佳频率反应域增大.对于少数神经元,弱背景噪声并未显著改变其频率调谐范围,但却改变了其最佳频率反应域范围.弱背景噪声对63.64%神经元的特征频率和55.84%神经元的最低阈值无显著影响.神经元频率调谐曲线的尖部比中部更容易受到弱背景噪声的影响.该研究结果有助于我们进一步理解复杂声环境下大脑听皮层对听觉信息的编码机制.     

大鼠生后发育过程中听皮层神经元特征频率的可塑性

应用常规电生理学技术,以神经元的特征频率和频率调谐曲线为指标,分别在生后2、3、4、5、6和8周龄SD大鼠上,研究生后发育过程中,听皮层神经元特征频率的可塑性.结果表明,在给予条件刺激频率和神经元特征频率相差1.0kHz范围内,条件刺激都可诱导各年龄组神经元特征频率向频率调谐曲线的低频端、高频端或调谐曲线的两端相应的偏移.特征频率偏移的概率与年龄相关.随着年龄的增长,特征频率偏移的比例下降,而不偏移的比例则上升.随着年龄增长,那些Q10-dB值大和频率调谐曲线对称指数大于零的神经元,特征频率偏移到频率调谐曲线高频端的比例增加更为明显(P<0.01).诱导特征频率完全偏移的时程和特征频率恢复的时程也与动物的年龄相关,随着年龄增长,诱导和恢复时程都明显延长(P<0.05).结果提示,大鼠听皮层神经元特征频率的可塑性与生后年龄相关,为深入研究中枢神经元功能活动可塑性的机制提供了重要实验资料.     

基于联合锋电位-局部场电位的整合野调制特性研究

整合野调制在生物视觉系统的图形背景分离和轮廓检测中具有重要作用。为了研究整合野空间频率调制特性,首先测定单个神经元的感受野范围和整合类型,挑选出要研究的抑制性神经元;然后,用匹配追踪算法和希尔伯特变换提取Spike触发的伽马频带LFP瞬时能量;最后,将Spike触发的伽马频带LFP(local field potential,LFP)瞬时能量用于分析神经元的整合调制特性.对在大鼠初级视觉皮层(primary visual cortex,V1区)采集的96个神经元进行统计分析,实验结果表明:1)Spike触发的伽马频带LFP瞬时能量可以作为分析V1区整合野调制特性的有效指标;2)基于Spike触发的伽马频带LFP瞬时能量所获得的抑制指数要显著高于通过Spike发放率以及伽马频带LFP功率的结果(P0.001),并且整合野的调制规律性更加明显,个体适用性更好。     

外周损伤引起成年大鼠体感皮层的功能重组

为了了解外周神经损伤对体感皮层分域组构的影响,在成年大鼠上观察了切断坐骨神经(SC)前、即刻和切断后数周内后爪皮层代表区的改变。在盐酸氯胺酮麻醉下,用微电极记录后爪皮肤轻触刺激在对侧体感皮层工区诱发的多单位反应,得出后爪的皮层代表区图。在16例中,8例大鼠观察了切断SC的即时效应。结果表明,不但SC代表区丧失皮肤反应性,原隐神经(SA)代表区的皮肤反应性也明显下降或消失,同时神经元自发活动也明显减弱。另8例大鼠在切断后数周内做了1～3次重复测定。在最初几天,原SA代表区范围内多数记录点的皮肤反应性仍未恢复,但在原SC代表区内,一些记录点转而对SA皮肤轻触刺激起反应。在随后数周内SA代表区进行性地扩张,占领了大部分原SC代表区。这一结果说明成年大鼠外周神经损伤可导致体感皮层发生显著的重组改变。     

二甲双胍调节初级视觉皮层兴奋性和抑制性平衡及改善视觉功能的研究

大脑皮层中兴奋和抑制系统之间的动态平衡决定了皮层神经元对刺激的反应特性. 已有研究表明,二甲双胍能够诱导γ-氨基丁酸受体向突触后膜聚集,增强神经系统的抑制效果. 本课题进一步探讨了二甲双胍对初级视觉皮层兴奋和抑制系统平衡的调节作用,以及其改善小鼠视觉功能的潜力. 实验使用成年雄性小鼠,实验组（metformin）10只每天给予二甲双胍250 mg/kg,对照组（control）6只每天给予0.3 ml生理盐水,灌胃处理3周. 结果发现二甲双胍可以显著升高囊泡GABA转运蛋白VGAT和突触后抑制性递质受体相关蛋白Gephyrin的合成. 此外,它显著降低突触后兴奋性受体GluA1和GluN1的表达. 多通道电极电生理记录结果显示,二甲双胍作用下小鼠初级视觉皮层的自发放和诱发放显著降低,而信噪比、方向和方位选择性显著增加. 实验结果表明,二甲双胍可以通过降低兴奋突触、增强抑制突触,调节初级视皮层的兴奋——抑制平衡,提高信息处理能力,增强视觉功能.     

猫体感皮层神经元对同时刺激隐神经的A类和C类纤维的反应型式

记录了麻痹猫的体感皮层(SI)神经元的自发和隐神经的A类和C类纤维传入诱发放电(A-ED和C-ED)。用NCCVF分析神经元放电。结果表明,SI区神经元对同时刺激隐神经的A类和C类纤维的反应呈多种型式:(1)A-ED和C-ED共存,包括Ⅰ.A-ED和C-ED始终相互伴随出现;Ⅱ.在刺激之初,只出现A-ED,但是,当阻断A类纤维传入并由C类纤维传入诱发神经元放电后,再同时刺激A类和C类纤维时,A-ED和C-ED便同时出现。(2)A-ED制约C-ED,特点是,只要A-ED存在,C/ED就不出现。只有阻断A类纤维传入后,C-ED才产生。(3)单一A-ED,不管在什么刺激条件下,这类神经元都只有A-ED,而不产生C-ED 结论:根据反应型式的不同,可将SI区的神经元分为Ⅰ.A类和C类纤维传入同时驱动的神经元;Ⅱ.A-ED制约C-ED的神经元;Ⅲ.只由A类纤维传入驱动的神经元。     

HCV 1a/1b型嵌合体能在HepG2细胞内复制与表达

采用HCV 1a/1b嵌合体cDNA构建表达质粒转染HepG2细胞,以免疫组化和Western blotting检测HCV蛋白表达,RT-PCR检测HCV正、负链RNA,研究丙型肝炎病毒(HCV)1a和1b型嵌合体全长cDNA在HepG2细胞中的复制和表达.结果证明,转染细胞中检测到分子量约70 kDa的HCV NS3蛋白, 转染细胞连续传20代, 仍能检测到HCV正、负链RNA.表明该HCV嵌合体可以在细胞中复制和表达,HCV 1b型的RNA依赖的RNA聚合酶(RdRp)可以起始含1a型非编码区的病毒复制. HCV 5′端非翻译区第11、12、13、34和35位核苷酸改变可不影响其与核糖体结合.3′非翻译区9400,9403和9407位核苷酸改变,9435位缺失"A",9409,9410位及9495,9496,9497位分别插入"TT"和"AAT"可不影响RdRp的生物活性.本研究对阐明HCV复制和翻译机制有重要意义.     

弗洛伊德“人格结构”与麦克林“脑三位一体”学说--《神经美学》教学中遇到的问题、解决方案与讲义

《神经美学》课程在中国科学院大学(国科大)生命科学学院首次开设,吸引了来自生命科学学院内外34种不同专业的99位研究生选课.神经科学或心理学专业的学生占26.5%,虽来自生命科学专业但神经科学知识基础相对薄弱的学生占63.5%,完全没有涉猎过神经科学和心理学的理工科学生占10%.因此,在教学过程中,既要讲授神经科学等方面的基础知识使初学者得以理解《神经美学》,又要时时吸引神经科学和心理学专业研究生的学习兴趣.为此,我们设计了一个有针对性的教学方案,即把《神经美学》专业内容与相关神经科学的基础知识和前沿研究成果匹配在一起讲授,同时注意与学生互动、讨论.比如,在讲授弗洛伊德"人格心理结构"时,先介绍麦克林"脑三位一体"学说和"脑的弥散性调节系统",再讲解"本我"与原始皮层和古皮层、"超我"与新皮层,以及"自我"、"本我"和"超我"的关系.然后讨论艺术创作、审美体验的神经基础,以及对经典画作的理解和审美等.课程内容从人格心理、脑结构、神经元、分子(神经递质)四个层次,为学生构建了一个较为宽广的思维空间.从学生课后提交的学习心得来看,此次教学不仅激发了他们对《神经美学》的兴趣和学习热情,同时提高了学生从美学角度进行思考以及追求美的意识.     

Areal Distributions of Cortical Neurons Projecting to Different Levels of the Caudal Brain Stem and Spinal Cord in Rats

Distributions of corticospinal and corticobulbar neurons were revealed by tetramethylbenzidine (TMB) processing after injections of wheatgerm agglutinin conjugated to horseradish peroxidase (WGA:HRP) into the cervical or lumbar enlargements of the spinal cord, or medullary or pontine levels of the brain stem. Sections reacted for cytochrome oxidase (CO) allowed patterns of labeled neurons to be related to the details of the body surface map in the first somatosensory cortical area (SI). The results indicate that a number of cortical areas project to these subcortical levels: (1) Projection neurons in granular SI formed a clear somatotopic pattern. The hindpaw region projected to the lumbar enlargement, the forepaw region to the cervical enlargement, the whisker pad field to the lower medulla, and the more rostral face region to more rostral brain stem levels. (2) Each zone of labeled neurons in SI extended into adjacent dysgranular somatosensory cortex, forming a second somatotopic pattern of projection neurons. (3) A somatotopic pattern of projection neurons in primary motor cortex (MI) paralleled SI in mediolateral sequence corresponding to the hindlimb, forelimb, and face. (4) A weak somatotopic pattern of projection neurons was suggested in medial agranular cortex (Ag_m), indicating a premotor field with a rostromedial-to-caudolateral representation of hindlimb, forelimb, and face. (5) A somatotopic pattern of projection neurons representing the foot to face in a mediolateral sequence was observed in medial parietal cortex (PM) located between SI and area 17. (6) In the second somatosensory cortical area (SII), neurons projecting to the brain stem were immediately adjacent caudolaterally to the barrel field of SI, whereas neurons projecting to the upper spinal cord were more lateral. No projection neurons in this region were labeled by the injections in the lower spinal cord. (7) Other foci of projection neurons for the face and forelimb were located rostral to SII, providing evidence for a parietal ventral area (PV) in perirhinal cortex (PR) lateral to SI, and in cortex between SII and PM. None of these regions, which may be higher-order somatosensory areas, contained labeled neurons after injections in the lower spinal cord. Thus, more cortical fields directly influence brain stem and spinal cord levels related to sensory and motor functions of the face and forepaw than the hindlimb.

The termination patterns of corticospinal and corticobulbar projections were studied in other rats with injections of WGA:HRP in SI. Injections in lateral SI representing the face produced dense terminal label in the contralateral trigeminal complex. Injections in cortex devoted to the forelimb and forepaw labeled the contralateral cuneate nucleus and parts of the dorsal horn of the spinal cord. The cortical injections also demonstrated interconnections of parts of SI with some of the other regions of cortex with projections to the spinal cord, and provided further evidence for the existence of PV in rats.     

A Dynamical Model of Fast Cortical Reorganization

In this work we study the connection between some dynamic effects at the synaptic level and fast reorganization of cortical sensory maps. By using a biologically plausible computational model of the primary somatosensory system we obtained simulation results that can be used to relate the dynamics of the interactions of excitatory and inhibitory neurons to the process of somatotopic map reorganization immediately after peripheral lesion. The model consists of three regions integrated into a single structure: tactile receptors representing the glabrous surface of the hand, ventral posterior lateral nucleus of the thalamus and area 3b of the primary somatosensory cortex, reproducing the main aspects of the connectivity of these regions. By applying informational measures to the simulation results of the dynamic behavior of AMPA, NMDA and GABA synaptic conductances we draw some conjectures about how the several neuronal synaptic elements are related to the initial stage of the digit-induced reorganization of the hand map in the somatosensory cortex.     

Effects of reversible cold block of face primary somatosensory cortex on orofacial movements and related face primary motor cortex neuronal activity

Our previous studies have revealed that face primary somatosensory cortex (SI) as well as face primary motor cortex (MI) play important roles in the control of orofacial movements in awake monkeys, and that both face MI and face SI neurons may have an orofacial mechanoreceptive field and show activity related to orofacial movements. Since it is possible that the movement-related activity of face MI neurons could reflect movement-generated orofacial afferent inputs projecting to face MI via face SI, the present study used reversible cold block-induced inactivation of the monkey's face SI to determine if face MI neuronal activity related to a trained tongue-protrusion task, chewing or swallowing was dependent on the functional integrity of the ipsilateral face SI and if inactivation of face SI affects orofacial movements. The effects of face SI cold block were tested on chewing, swallowing and/or task-related activity of 73 face MI neurons. Both task and chewing and/or swallowing-related activity of most face MI neurons was independent of the functional integrity of the ipsilateral face SI since SI cold block affected the movement-related activity in approximately 25% of the neurons. Similarly, unilateral cold block of SI had very limited effects on the performance of the task and chewing, and no effect on the performance of swallowing. These findings suggest that movement-induced reafferentation via face SI may not be a significant factor in accounting for the activity of the majority of ipsilateral face MI neurons related to trained movements, chewing and swallowing.     

Organization of cortical processing for facial movements during licking in cats

We proposed that cortical organization for the execution of adequate licking in cats was processed under the control of two kinds of affiliated groups for face and jaw & tongue movements (Hiraba H, Sato T. 2005A. Cerebral control of face, jaw, and tongue movements in awake cats: Changes in regional cerebral blood flow during lateral feeding Somatosens Mot Res 22:307–317). We assumed the cortical organization for face movements from changes in MRN (mastication-related neuron) activities recorded at area M (motor cortex) and orofacial behaviors after the lesion in the facial SI (facial region in the primary somatosensory cortex). Although we showed the relationship between facial SI (area 3b) and area M (area 4δ), the property of area C (area 3a) was not fully described. The aim of this present study is to investigate the functional role of area C (the anterior part of the coronal sulcus) that transfers somatosensory information in facial SI to area M, as shown in a previous paper (Hiraba H. 2004. The function of sensory information from the first somatosensory cortex for facial movements during ingestion in cats Somatosens Mot Res 21:87--97). We examined the properties of MRNs in area C and changes in orofacial behaviors after the area C or area M lesion. MRNs in area C had in common RFs in the lingual, perioral, and mandibular parts, and activity patterns of MRNs showed both post- and pre-movement types. Furthermore, cats with the area C lesion showed similar disorders to cats with the area M lesion, such as the dropping of food from the contralateral mouth, prolongation of the period of ingestion and mastication, and so on. From these results, we believe firmly the organization of unilateral cortical processing in facial SI, area C, and area M for face movements during licking.     

Areal distributions of cortical neurons projecting to different levels of the caudal brain stem and spinal cord in rats

Distributions of corticospinal and corticobulbar neurons were revealed by tetramethylbenzidine (TMB) processing after injections of wheatgerm agglutinin conjugated to horseradish peroxidase (WGA:HRP) into the cervical or lumbar enlargements of the spinal cord, or medullary or pontine levels of the brain stem. Sections reacted for cytochrome oxidase (CO) allowed patterns of labeled neurons to be related to the details of the body surface map in the first somatosensory cortical area (SI). The results indicate that a number of cortical areas project to these subcortical levels: (1) Projection neurons in granular SI formed a clear somatotopic pattern. The hindpaw region projected to the lumbar enlargement, the forepaw region to the cervical enlargement, the whisker pad field to the lower medulla, and the more rostral face region to more rostral brain stem levels. (2) Each zone of labeled neurons in SI extended into adjacent dysgranular somatosensory cortex, forming a second somatotopic pattern of projection neurons. (3) A somatotopic pattern of projection neurons in primary motor cortex (MI) paralleled SI in mediolateral sequence corresponding to the hindlimb, forelimb, and face. (4) A weak somatotopic pattern of projection neurons was suggested in medial agranular cortex (Agm), indicating a premotor field with a rostromedial-to-caudolateral representation of hindlimb, forelimb, and face. (5) A somatotopic pattern of projection neurons representing the foot to face in a mediolateral sequence was observed in medial parietal cortex (PM) located between SI and area 17. (6) In the second somatosensory cortical area (SII), neurons projecting to the brain stem were immediately adjacent caudolaterally to the barrel field of SI, whereas neurons projecting to the upper spinal cord were more lateral. No projection neurons in this region were labeled by the injections in the lower spinal cord. (7) Other foci of projection neurons for the face and forelimb were located rostral to SII, providing evidence for a parietal ventral area (PV) in perirhinal cortex (PR) lateral to SI, and in cortex between SII and PM. None of these regions, which may be higher-order somatosensory areas, contained labeled neurons after injections in the lower spinal cord. Thus, more cortical fields directly influence brain stem and spinal cord levels related to sensory and motor functions of the face and forepaw than the hindlimb. The termination patterns of corticospinal and corticobulbar projections were studied in other rats with injections of WGA:HRP in SI.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effects of reversible cold block of face primary somatosensory cortex on orofacial movements and related face primary motor cortex neuronal activity

Our previous studies have revealed that face primary somatosensory cortex (SI) as well as face primary motor cortex (MI) play important roles in the control of orofacial movements in awake monkeys, and that both face MI and face SI neurons may have an orofacial mechanoreceptive field and show activity related to orofacial movements. Since it is possible that the movement-related activity of face MI neurons could reflect movement-generated orofacial afferent inputs projecting to face MI via face SI, the present study used reversible cold block-induced inactivation of the monkey's face SI to determine if face MI neuronal activity related to a trained tongue-protrusion task, chewing or swallowing was dependent on the functional integrity of the ipsilateral face SI and if inactivation of face SI affects orofacial movements. The effects of face SI cold block were tested on chewing, swallowing and/or task-related activity of 73 face MI neurons. Both task and chewing and/or swallowing-related activity of most face MI neurons was independent of the functional integrity of the ipsilateral face SI since SI cold block affected the movement-related activity in approximately 25% of the neurons. Similarly, unilateral cold block of SI had very limited effects on the performance of the task and chewing, and no effect on the performance of swallowing. These findings suggest that movement-induced reafferentation via face SI may not be a significant factor in accounting for the activity of the majority of ipsilateral face MI neurons related to trained movements, chewing and swallowing.     

Somatosensory areas S2 and PV project to the superior colliculus of a prosimian primate,Galago garnetti

As part of an effort to describe the connections of the somatosensory system in Galago garnetti, a small prosimian primate, injections of tracers into cortex revealed that two somatosensory areas, the second somatosensory area (S2) and the parietal ventral somatosensory area (PV), project densely to the ipsilateral superior colliculus, while the primary somatosensory area (S1 or area 3b) does not. The three cortical areas were defined in microelectrode mapping experiments and recordings were used to identify appropriate injection sites in the same cases. Injections of wheat germ agglutinin conjugated with horseradish peroxidase (WGA-HRP) were placed in S1 in different mediolateral locations representing body regions from toes to face in five galagos, and none of these injections labeled projections to the superior colliculus. In contrast, each of the two injections in the face representation of S2 in two galagos and three injections in face and forelimb representations of PV in three galagos produced dense patches of labeled terminations and axons in the intermediate gray (layer IV) over the full extent of the superior colliculus. The results suggest that the higher-order somatosensory areas, PV and S2, are directly involved in the visuomotor functions of the superior colliculus in prosimian primates, while S1 is not. The somatosensory inputs appear to be too widespread to contribute to a detailed somatotopic representation in the superior colliculus, but they may be a source of somatosensory modulation of retinotopically guided oculomotor instructions.     

Organization of cortical processing for facial movements during licking in cats

We proposed that cortical organization for the execution of adequate licking in cats was processed under the control of two kinds of affiliated groups for face and jaw & tongue movements (Hiraba H, Sato T. 2005A. Cerebral control of face, jaw, and tongue movements in awake cats: Changes in regional cerebral blood flow during lateral feeding Somatosens Mot Res 22:307-317). We assumed the cortical organization for face movements from changes in MRN (mastication-related neuron) activities recorded at area M (motor cortex) and orofacial behaviors after the lesion in the facial SI (facial region in the primary somatosensory cortex). Although we showed the relationship between facial SI (area 3b) and area M (area 4delta), the property of area C (area 3a) was not fully described. The aim of this present study is to investigate the functional role of area C (the anterior part of the coronal sulcus) that transfers somatosensory information in facial SI to area M, as shown in a previous paper (Hiraba H. 2004. The function of sensory information from the first somatosensory cortex for facial movements during ingestion in cats Somatosens Mot Res 21:87-97). We examined the properties of MRNs in area C and changes in orofacial behaviors after the area C or area M lesion. MRNs in area C had in common RFs in the lingual, perioral, and mandibular parts, and activity patterns of MRNs showed both post- and pre-movement types. Furthermore, cats with the area C lesion showed similar disorders to cats with the area M lesion, such as the dropping of food from the contralateral mouth, prolongation of the period of ingestion and mastication, and so on. From these results, we believe firmly the organization of unilateral cortical processing in facial SI, area C, and area M for face movements during licking.     

Somatosensory areas S2 and PV project to the superior colliculus of a prosimian primate, Galago garnetti

As part of an effort to describe the connections of the somatosensory system in Galago garnetti, a small prosimian primate, injections of tracers into cortex revealed that two somatosensory areas, the second somatosensory area (S2) and the parietal ventral somatosensory area (PV), project densely to the ipsilateral superior colliculus, while the primary somatosensory area (S1 or area 3b) does not. The three cortical areas were defined in microelectrode mapping experiments and recordings were used to identify appropriate injection sites in the same cases. Injections of wheat germ agglutinin conjugated with horseradish peroxidase (WGA-HRP) were placed in S1 in different mediolateral locations representing body regions from toes to face in five galagos, and none of these injections labeled projections to the superior colliculus. In contrast, each of the two injections in the face representation of S2 in two galagos and three injections in face and forelimb representations of PV in three galagos produced dense patches of labeled terminations and axons in the intermediate gray (layer IV) over the full extent of the superior colliculus. The results suggest that the higher-order somatosensory areas, PV and S2, are directly involved in the visuomotor functions of the superior colliculus in prosimian primates, while S1 is not. The somatosensory inputs appear to be too widespread to contribute to a detailed somatotopic representation in the superior colliculus, but they may be a source of somatosensory modulation of retinotopically guided oculomotor instructions.     

Inferior parietal somatosensory neurons coding face-hand coordination in Japanese macaques

Neuronal activities of the anterior part of the inferior parietal lobule (area 7b or PF) were investigated in five awake Japanese monkeys. There were neurons which had specific combinations of receptive field (RF) locations, most typically in both the face and hand; we refer to these as Face-Hand neurons. The most interesting property of the Face-Hand neurons is that some of these neurons responded to specific behavior executed with synergism between the face (especially the mouth) and hand movements; namely, face-hand coordinated behavior (e.g., eating behavior). We call these cells Face-Hand coordination neurons (52% of all the Face-Hand neurons). These neurons discharged more strongly when the animal executed face-hand coordinated behavior, especially eating behavior, than when somatosensory stimuli were given to RFs passively, or when face movements and hand movements were executed separately. We thus propose that the neuronal activities of area 7b are related to the representation of face-hand coordination.