A quantitative analysis of the local connectivity between pyramidal neurons in layers 2/3 of the rat visual cortex

被引:221
作者
Hellwig, B [1 ]
机构
[1] Max Planck Inst Biol Kybernet, D-72076 Tubingen, Germany
关键词
D O I
10.1007/PL00007964
中图分类号
TP3 [计算技术、计算机技术];
学科分类号
0812 ;
摘要
This study provides a detailed quantitative estimate for local synaptic connectivity between neocortical pyramidal neurons. A new way of obtaining such an estimate is presented. In acute slices of the rat visual cortex, four layer 2 and four layer 3 pyramidal neurons were intracellularly injected with biocytin. Axonal and dendritic arborizations were three-dimensionally reconstructed with the aid of a computer-based camera lucida system. In a computer experiment, pairs of pre- and postsynaptic neurons were formed and potential synaptic contacts were calculated. For each pair, the calculations were carried out for a whole range of distances (0 to 500 mu m) between the presynaptic and the postsynaptic neuron, in order to estimate cortical connectivity as a function of the spatial separation of neurons. It was also differentiated whether neurons were situated in the same or in different cortical layers. The data thus obtained was used to compute connection probabilities, the average number of contacts between neurons, the frequency of specific numbers of contacts and the total number of contacts a dendritic tree receives from the surrounding cortical volume. Connection probabilities ranged from 50% to 80% for directly adjacent neurons and from 0% to 15% for neurons 500 mu m apart. In many cases? connections were mediated by one contact only. However, close neighbors made on average up to 3 contacts with each other. The question as to whether the method employed in this study yields a realistic estimate of synaptic connectivity is discussed. It is argued that the results can be used as a detailed blueprint for building artificial neural networks with a cortex-like architecture.
引用
收藏
页码:111 / 121
页数:11
相关论文
共 37 条
[1]  
Abeles M., 1982, LOCAL CORTICAL CIRCU, DOI DOI 10.1007/978-3-642-81708-3
[2]  
Abeles M., 1991, CORTICONICS
[3]  
[Anonymous], ARCHITECTONICS CEREB
[4]  
[Anonymous], LECTURE NOTES BIOMAT
[5]  
Braitenberg V., 1991, ANATOMY CORTEX STAT
[6]   INTRINSIC CONNECTIONS OF RAT PRIMARY VISUAL-CORTEX - LAMINAR ORGANIZATION OF AXONAL PROJECTIONS [J].
BURKHALTER, A .
JOURNAL OF COMPARATIVE NEUROLOGY, 1989, 279 (02) :171-186
[7]   RELATIONSHIPS BETWEEN MORPHOLOGY AND PHYSIOLOGY OF PYRAMID-PYRAMID SINGLE AXON CONNECTIONS IN RAT NEOCORTEX IN-VITRO [J].
DEUCHARS, J ;
WEST, DC ;
THOMSON, AM .
JOURNAL OF PHYSIOLOGY-LONDON, 1994, 478 (03) :423-435
[8]   DISTRIBUTION OF NEURONS AND GLIA IN THE VISUAL-CORTEX (AREA-17) OF THE ADULT ALBINO-RAT - A QUANTITATIVE DESCRIPTION [J].
GABBOTT, PLA ;
STEWART, MG .
NEUROSCIENCE, 1987, 21 (03) :833-845
[9]   CONNECTIONS BETWEEN PYRAMIDAL NEURONS IN LAYER-5 OF CAT VISUAL-CORTEX (AREA-17) [J].
GABBOTT, PLA ;
MARTIN, KAC ;
WHITTERIDGE, D .
JOURNAL OF COMPARATIVE NEUROLOGY, 1987, 259 (03) :364-381
[10]  
GILBERT CD, 1983, J NEUROSCI, V3, P1116