The regional distributions of monamine oxidase (MAO) (EC 1.4.3.4), catechol-0methyltransferase (COMT) (EC 2.1.1.6), tyrosine hydroxylase (TH) (EC 1.14.3.2), and dopamine-Phydroxylase (DBH) (EC 1.14.2.1) have been examined in human brains obtained at autopsy from persons who died of natural causes (controls), and from persons who committed suicide and were further categorized as suffering from affective disorder (depression) or from alcoholism. Post mortem animal studies showed no changes in M A 0 or COMT activities in rabbit brain or in DBH activity in rat brain when the intact bodies were left at room temperature up to 24 h. T H activity in rabbit brains, however, began to decline immediately after death and after 24 h at room temperature it was approximately 48 per cent of the fresh brain level. There was no significant variation in activity of COMT, TH and DBH in human brain attributable to age or sex. M A 0 activities in the 60-70 yr decade were 34 per cent higher than in the 30-40 yr decade. M A 0 activities were highest in the hypothalamus and substantia nigra, T H activities were highest in substantia nigra, putamen and head of caudate, and DBH activities were greatest in tegmentum of pons and hypothalamus. Only minimal regional differences in COMT activities were observed. No significant differences were found between enzyme activities in brain areas of controls and suicides with the possible exception of T H in the substantia nigra, where the depressive suicides (but not the alcoholics) showed greater activity ( P < 0.02). These findings appear not to support the catecholamine hypothesis of affective disorder.
Many investigators have studied the relationship between life events and psychiatric illness to discover whether certain events predispose to some disorders or precipitate them, and to discover the effect of illnesses already in progress on subsequent life events and the effect of events on established illnesses. The validity of such studies depends, among other things, on the selection of suitable controls. For example, if adult patients with depression differ from a group of controls in that they had a higher incidence of parental death, it might indicate that bereavement had made them more susceptible to the development of the illness. But if the depressed patients were from a lower social class than their controls, the greater incidence of bereavement might be explained by the fact that there is a higher death rate in that stratum of society. This would then cast doubt on a conclusion about a causal relationship in that group between childhood bereavement and depression in adult life.
Degenerative changes in the cerebellum of the cat have been observed electron microscopically 2 to 30 days after surgical lesions were placed in the inferior or middle cerebellar peduncles or after undercutting or isolating cerebellar folia. The changes were confined to the mossy fibers of the white matter and granular layer except when Purkinje cells were damaged by undercutting. Mossy fiber terminals in the glomeruli underwent two kinds of change. Either the synaptic vesicles and mitochondria coalesced into dense clumps with loss of mitochondrial outer membranes and Proliferation of cristae, or the vesicles and mitochondria disappeared leaving a swollen terminal containing only a few large pleomorphic vesicles and small dense polygonal bodies. Neurofilaments proliferated and filled a few terminals but most of the neurofilamentous hypertrophy and proliferation was confined to myelinated axons. Some phagocytosis of degenerated endings was observed and mild fibrous gliosis occurred in the glomeruli.All of the changes observed in the present study have been reported in degenerating synapses and axons elsewhere in the central and peripheral nervous system, but there appeared to be more pleomorphism and less. predictability of changes in the cerebellar cortex than have been noted in other single areas of the central nervous system.
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