CONGRUENCE OF SPATIAL-ORGANIZATION OF TACTILE PROJECTIONS TO GRANULE CELL AND PURKINJE-CELL LAYERS OF CEREBELLAR HEMISPHERES OF THE ALBINO-RAT - VERTICAL ORGANIZATION OF CEREBELLAR CORTEX
CONGRUENCE OF SPATIAL-ORGANIZATION OF TACTILE PROJECTIONS TO GRANULE CELL AND PURKINJE-CELL LAYERS OF CEREBELLAR HEMISPHERES OF THE ALBINO-RAT - VERTICAL ORGANIZATION OF CEREBELLAR CORTEX
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DOI：
10.1152/jn.1983.49.3.745
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发表时间：
1983-01-01
影响因子：
2.5
通讯作者：
WOOLSTON, DC
中科院分区：
文献类型：
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作者：
BOWER, JM;WOOLSTON, DC
比较了大鼠小脑皮质触觉区域浦肯野细胞（PC）层和底层颗粒细胞（GC）层的最短潜伏期体感（触觉）投射的空间模式。使用显微绘图方法对麻醉和未麻醉大鼠的 PC 层中的单个单元和 GC 层中的多个单元进行采样。采用对体表的机械和电刺激。通过构建简单尖峰活动的直方图并将刺激后活动与未刺激的基线PC活动进行统计比较来评估PC对皮肤刺激的反应性。 PC 对触觉刺激的反应是简单尖峰活动先增加（7-10 毫秒），然后减少（8-15 毫秒）。底层 GC 层激活 1-4 毫秒后，简单尖峰活性增加，而 GC 层激活 2-5 毫秒后，简单尖峰活性降低。 PC 具有兴奋性和抑制性感受野 (RF)。兴奋性 RF 仅限于单个身体部位的小区域，并且对于每个 PC 来说，其与紧邻的 GC 层中神经元的 RF 非常相似或相同。抑制性 PC RF 较大，通常包含多个身体部位，并且对于每个 PC，仅部分类似于下面 GC 的 RF。 PC 抑制性 RF 还经常包括投射到附近但不投射到下面的 GC 层的体表。单个外周位点的刺激导致 PC 层兴奋和抑制的小而独特的区域。 PC 激发区域覆盖 GC 层的激活区域，而 PC 抑制区域覆盖激活和非激活 GC 区域。 PC根据能够激活它们的特定身体区域（上唇、下唇等）被组织成组或斑块。相邻的 PC 块通常代表相距较远的身体部位。 PC 层激活 RF 投射的这种模式与下面 GC 层的兴奋性 RF 投射的模式一致。结果表明，GC-PC 兴奋关系存在垂直组织，而 GC 诱导的 PC 抑制分布稍广泛。 PC 的片状激活与底层 GC 层的激活一致，这与 PC 由来自 GC 片的平行纤维以束状方式激活的经典概念形成鲜明对比。重新评估平行纤维的作用似乎有必要。小脑皮质 GC 层和 PC 层的短延迟传入触觉投射在空间上是高度组织的这一观点得到了支持。体表投射的这种特殊性必须纳入小脑皮质功能组织的现代观点中。
The spatial patterns of shortest latency somatosensory (tactile) projections to the Purkinje cell (PC) layer and to the underlying granule cell (GC) layer in tactile areas of rat cerebellar cortex were compared. Micromapping methods were used to sample single units in the PC layer and multiple units in the GC layer of both anesthetized and unanesthetized rats. Mechanical and electrical stimulation of the body surface were employed. Responsiveness of PC to cutaneous stimulation was assessed by constructing histograms of simple spike activity and statiscally comparing poststimulus activity to nonstimulated base-line PC activity. PC respond to tactile stimulation with increases (7-10 ms) followed by decreases (8-15 ms) in simple spike activity. Increases in simple spike activity followed activation of the underlying GC layer by 1-4 ms, while decreases in simple spike activity were found 2-5 ms after GC layer activation. PC had both excitatory and inhibitory receptive fields (RF). Excitatory RF were restricted to small areas of a single body part and for each PC were very similar or identical to the RF of neurons in the immediately subjacent GC layer. Inhibitory PC RF were larger, often containing more than one body part and for each PC, were only partially similar to the RF of subjacent GC. PC inhibitory RF also often included body surfaces projecting to the nearby but not to the underlying GC layer. Stimulation of a single peripheral locus resulted in small, distinct regions of PC layer excitation and inhibition. Areas of PC excitation overlie activated regions of the GC layer, while inhibited PC overlie both activated and nonactivated GC regions. PC were organized in groups or patches with respect to the specific body region that was capable of activating them (upper lip, lower lip, etc.). Adjacent patches of PC often represented widely separated body parts. This pattern of PC layer activating RF projections was congruent with the pattern of excitatory RF projections to the underlying GC layer. Results indicate that there is a vertical organization in GC-PC excitatory relations, while GC-induced PC inhibition is slightly more widely distributed. The patchlike activation of PC being congruent with that of the underlying GC layer contrasts with the classical concept that PC are activated by parallel fibers in a beamlike fashion from a patch of GC. A reevaluation of the role of parallel fibers seems necessary. The view that short-latency afferent tactile projections to both the GC and PC layers of cerebellar cortex are highly organized spatially is supported. This specificity of body surface projections must be incorporated into modern views of the functional organization of cerebellar cortex.