R. W. Hiorns

Association between smoking and drinking and sleep duration

In a study of lifestyles and health of the adult population of some Oxfordshire villages, data were collected upon the usual sleep duration and quality, smoking and drinking habits of 725 men and 759 women. A strong negative association has been found between cigarette smoking and sleep duration on both sexes, and between alcohol consumption and sleep duration in men. There is no equivalent association between drinking or smoking and reported poor quality sleep. While these findings do not prove a causal relationship, the absence of complaints of poor quality sleep among the smokers and drinkers suggests that these habits are not simply the correlates of underlying psychological problems leading to insomnia.

Clustering of ipsilateral cortico-cortical projection neurons to area 7 in the rhesus monkey

The distribution within individual cytoarchitectonic areas of the cells of origin of ipsilateral cortico-cortical fibres to area 7 of the parietal lobe of the monkey has been studied. After injections of horseradish peroxidase into area 7, labelled cells in a variety of cortical areas were plotted and their distribution along the length of the cortex analysed. Significant clustering of labelled cells was seen wherever their numbers were sufficient for meaningful statistical analysis. In most cases, further analysis using correlation techniques revealed a significant banding of labelled cells across the cortex. Typical bands varied from 500-800 μm in width, and formed an irregular branching and rejoining pattern across the cortex. The intra-area distribution of cortico-cortical projection neurons is comparable to the distribution of neurofibrillary tangles in the cortex in Alzheimer’s disease.

Effects of monocular closure at different ages on deprived and undeprived cells in the primate lateral geniculate nucleus

This study has examined the effects of monocular visual deprivation on cells in the lateral geniculate nucleus of the primate by comparing the sizes of cells in deprived and undeprived LGN laminae of experimental rhesus monkeys with those of cells in the corresponding laminae of normal animals. A number of conclusions may be drawn from this comparison: monocular visual deprivation has major effects on cells in the undeprived LGN laminae and these vary with age at closure; the initial effect of monocular closure from birth is to cause marked hypertrophy of undeprived parvocellular cells with little shrinkage of the deprived parvocellular cells, whereas late monocular closure (after 2 months of age) causes marked shrinkage of both undeprived and deprived parvocellular cells; following monocular closure at birth, the LGN abnormality continues to evolve until at least 3 months of age, with a marked parallel shrinkage affecting both deprived and undeprived parvocellular cells. The initial hypertrophy of the undeprived cells is reversed and the deprived cells become smaller than normal; cells in the monkey LGN are sensitive to visual deprivation until about 1 year of age, much later than previously thought. Visual experience, however, modifies this sensitivity so that the effects of monocular visual deprivation are both qualitatively and quantitatively different at different ages; there are important differences between the susceptibility of cells in the magnocellular and parvocellular laminae to visual deprivation; and actual shrinkage of cells to markedly below normal size occurs and the smaller size is not simply failure of growth.

A Quantitative Electron-Microscopical Study of the Postnatal Development of the Lateral Geniculate Nucleus in Normal Kittens and in Kittens with Eyelid Suture

The postnatal development of the lateral geniculate nucleus has been studied quantitatively with the electron microscope in normal kittens and in kittens with eyelid closure. The maturation of the synaptic organization of glomeruli in the normal kitten occurs during the period of susceptibility to eyelid closure and is due predominantly to a logarithmic increase in the number of symmetric presynaptic dendritic synapses. In contrast, the proportion of symmetric synapses falls with age in non-glomerular neuropil over this period. Unilateral and bilateral eyelid suture do not interfere with the normal development of the lateral geniculate nucleus.

Social class and marital distance in Oxford City.

A study has been made of social class distributions and their effects on marital movement in the city of Oxford from 1837 to the present day. The data have been obtained from the marriage registers of nine ecclesiastical parishes which transect the city. There is marked social class heterogeneity according to district, but when the data are combined some striking relationships between occupation and the distributions of marital distance emerge. In general distance decreases and amounts of city endogamy increase almost linearly as one moves from Class I to Class V. There appears to be, however, no very great increase in marital distance in this century as compared with the situation in the last two-thirds of the nineteenth century. Some of the differences between the social classes are due to differences in marital age, but even after this has been taken into account there remains a very statistically significant relationship between class and marital movement.

Cell sizes in the lateral geniculate nucleus of normal infant and adult rhesus monkeys

Measurements of mean cell area have been made in the lateral geniculate nuclei of 16 normal rhesus monkeys as a control for changes following visual deprivation. There is little variability between animals and no significant growth between 8 days of age and adulthood in the parvocellular laminae. The magnocellular laminae show more variability and some continuing growth after 8 days of age.

Sizes of neurons in the primate lateral geniculate nucleus during normal development

Measurements of cell area have been made in the lateral geniculate nuclei (LGNs) of 18 normal rhesus monkeys aged from 8 days to fully adult. There is much less variability between individual animals than had been thought from measurements of undeprived cells in experimental animals following visual deprivation. It is therefore possible to make reliable comparisons of cell size between different animals. There is no change in size of cells in the parvocellular laminae between 8 days of age and adulthood, although cells in the magnocellular laminae grow a little. In the primate, unlike the cat, the period of maximum sensitivity to visual deprivation does not correspond to a period of rapid cell growth in the LGN.

Shrinkage of cells in undeprived laminae of the monkey lateral geniculate nucleus following late closure of one eye.

Comparisons of mean cell area in the lateral geniculate nucleus between normal and monocularly deprived rhesus monkeys show that late closure at between 3 months and a year of age produces up to 25% shrinkage of cells in the undeprived parvocellular laminae and up to 30% shrinkage in the deprived parvocellular laminae.

A note on marital distances and movement, and age at marriage, in a group of Oxfordshire villages

An account is given of the patterns of pre-marital, marital, and post-marital movement and age of marriage according to social class among the present inhabitants of a group of Oxfordshire villages.

Effect of reopening an eye after a period of monocular deprivation on sizes of neurons in the primate lateral geniculate nucleus

Following monocular closure shortly after birth the deprived eye of 4 rhesus monkeys was reopened at different times. Following long-term recovery, cells in the undeprived laminae of the lateral geniculate nucleus of these animals were of normal size and those in the deprived laminae were markedly shrunken. Comparisons with animals monocularly deprived for similar periods indicate, however, that in 3 of these animals the undeprived parvocellular cells would have been markedly hypertrophied at the time of reopening the deprived eye, and in two of the animals, little shrinkage of the deprived parvocellular cells would have occurred by this time. Both undeprived and deprived parvocellular cells have therefore undergone marked shrinkage after the deprived eye had been reopened. The parallel shrinkage of deprived and undeprived parvocellular cells which occurs following closure at birth thus appears to be a consequence of the initial abnormalities produced by monocular closure rather than a direct result of the continuing lack of visual input to one eye.