Numbers of synapses were counted in columns of neuropil orientated at right angles to the pia in frontal and temporal regions from postmortem brains. In the frontal region of 28 patients aged 26–90 years there were 1.2×108 mm3 (SD 0.03×108), and in the temporal of 18 patients aged 16–90 years there were 1.4×108 mm3 (SD 0.04×108). Regression analysis showed a statistically significant (P<0.01) decrease with age for the frontal region but not the temporal. Four patients had been clinically diagnosed as suffering from Alzheimer-type dementia and had neurofibrillary tangles and numerous senile plaques in the cortex. The numbers of synapses in these four patients did not differ from the remaining apparently intellectually normal people.
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Blessed G, Tomlinson BE, Roth M (1968) The association between quantitative measures of dementia and senile change in the cerebral grey matter of elderly subjects. Br J Psychiatry 114:797–811
Bondareff W, Mountjoy CQ, Roth M (1981) Selective loss of neurones of origin of adrenergic projections to cerebral cortex (nucleus locus coeruleus) in senile dementia. Lancet I:783–784
Buell SJ, Coleman PD (1981) Dendritic growth in the aged human brain and failure of growth in senile dementia. Science 206:854–856
Cragg BG (1969) The effects of vision and dark rearing on the size and density of synapses in the lateral geniculate nucleus measured by electron microscopy. Brain Res 13:53–67
Cragg BG (1975) The density of synapses and neurons in normal, mentally defective and ageing human brains. Brain 98:81–90
Gibson PH, Tomlinson BE (1978) Vacuolation in the human cerebral cortex and its relationship to the interval between death and autopsy and to synapse numbers: an electron microscopic study. Neuropathol Appl Neurobiol 5:1–7
Gibson PH (1983) Form and distribution of senile plaques in silver impregnated sections in the brains of intellectually normal elderly people and people with Alzheimer-type dementia. Neuropathol Appl Neurobiol (in press)
Henderson G, Tomlinson BE, Gibson PH (1980) Cell counts in human cerebral cortex in normal adults throughout life using an image analysing computer. J Neurol Sci 46:133–136
Huttenlocher PR (1979) Synaptic density in human frontal cortex —developmental changes and effects of aging. Brain Res 163:195–205
Mehraein P, Yamada M, Tarnowska-Dziduszko E (1975) Quantitative study on dendrites and dendritic spines in Alzheimer's disease and senile dementia. In: Kreutzberg GW (ed) Advances in neurology, vol 12. Raven Press, New York, pp 453–458
Scheibel ME, Scheibel AB (1975) Structural changes in the aging brain. In: Brody H, Harman D, Ordy JM (eds) Aging, vol 1. Raven Press, New York, pp 11–37
Whitehouse PJ, Price DL, Struble RG, Coyle JT, De Long MR (1982) Alzheimer's disease and senile dementia: Loss of neurones in the basal forebrain. Science 215:1237–1239
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Gibson, P.H. EM study of the numbers of cortical synapses in the brains of ageing people and people with Alzheimer-type dementia. Acta Neuropathol 62, 127–133 (1983). https://doi.org/10.1007/BF00684929
- Cortical synapses
- Alzheimertype dementia