This study seeks relationships between the degree of dendrite complexity of four areas of the human cerebral cortex and the type of function subserved by those areas. Quantitative studies of basilar dendrite patterns in the trunk and hand-finger receptive zones of areas 3 and 1, superior gyrus of the prefrontal cortex (area 9), and supramarginal gyrus (area 39) of the parietal lobe, in the left hemisphere of 10 subjects are reported. Measurements of dendrite complexity were based on the Sholl method of counting dendrite intersections with a series of superimposed concentric rings centered on the middle of the neuron soma. The data were analyzed graphically to show (1) characteristic dendrite profiles generated by cells in each of these areas, (2) comparisons between dendrite systems of two paired areas, i.e., trunk vs. hand-finger, and hand-finger vs. supramarginal, and (3) cumulative dendrite-ring intersection patterns for all areas studied. The data provided only partial support for our working hypothesis suggesting a relationship between complexity of the dendrite arbor and the nature of the computational tasks performed by the area. However, complexity of dendrite systems in the trunk area was found to be generally less than that of any other. In addition, there were suggestive associations between the complexity of dendrite systems of the hand-finger zone of the primary sensory receptive area and the nature of the work with which the individual had been associated during his/her working life. It proved more difficult to discern relationships between structure and function in the cortical associative areas. The study underlines the large degree of interindividual variation in dendrite structure and the need for much more extensive information about the life history of individuals who serve as subjects for this type of study.
[1]
W. Rall.
Theory of Physiological Properties of Dendrites
,
1962,
Annals of the New York Academy of Sciences.
[2]
A. W. Rogers,et al.
The migration of neuroblasts in the developing cerebral cortex.
,
1965,
Journal of anatomy.
[3]
Arnold B. Scheibel,et al.
The postnatal development of the motor speech area: A preliminary study
,
1989,
Brain and Language.
[4]
W Rall,et al.
Changes of action potential shape and velocity for changing core conductor geometry.
,
1974,
Biophysical journal.
[5]
M. Diamond.
Anatomical Brain Changes Induced by Environment
,
1976
.
[6]
W. Penfield,et al.
SOMATIC MOTOR AND SENSORY REPRESENTATION IN THE CEREBRAL CORTEX OF MAN AS STUDIED BY ELECTRICAL STIMULATION
,
1937
.
[7]
W. Rall.
Distinguishing theoretical synaptic potentials computed for different soma-dendritic distributions of synaptic input.
,
1967,
Journal of neurophysiology.
[8]
W. Rall.
Time constants and electrotonic length of membrane cylinders and neurons.
,
1969,
Biophysical journal.
[9]
I. Fried,et al.
Dendritic organization of the anterior speech area
,
1985,
Experimental Neurology.
[10]
Y Yarom,et al.
Modulation of spike frequency by regions of special axonal geometry and by synaptic inputs.
,
1976,
Journal of neurophysiology.