Neurochemical activities in human temporal lobe related to aging and Alzheimer-type changes

Post mortem levels of thyrotropin-releasing hormone and neurotensin in the amygdala in Alzheimer's disease, schizophrenia and depression

The levels of neurotensin and thyrotropin-releasing hormone (TRH) in normal post mortem human amygdala have been compared with those in cases of schizophrenia, Alzheimer's disease and depression. Amongst various factors which can influence post mortem human brain biochemistry (including age, sex, post mortem delay, time of death, disease status and severity), sex difference appeared to be responsible for the most extensive variation. The levels of both peptides were nearly doubled in males compared with females and this increase was significant in the case of neurotensin. There was also a positive correlation between neurotensin and TRH levels. Although levels of neurotensin and TRH tended to be lower in the disease groups these trends did not reach significance.

The influence of agonal status on some neurochemical activities of postmortem human brain tissue

The number of general biochemical and specific neurochemical activities have been investigated in postmortem human brain tissue in relation to the terminal state of the patient. Cases were broadly divided into those dying after a period of normal or near normal health (Category A) and those dying after a prolonged period of severe illness (Category B). Whilst most of the metabolic and transmitter-related enzymes, amino acids and neuropeptides investigated were not significantly different between the two groups, there were in Category B highly significant reductions in glutamate decarboxylase, phosphofructokinase and tissue pH, and increases in several amino acids including, most extensively, tryptophan. The possible use of such activities as 'markers' of agonal status in the selection of normal material and in the matching of control and pathological material in postmortem human brain studies is discussed.