An analysis of the arrangement of neurons in the cingulate cortex of schizophrenic patients

A series of computer-assisted stereomorphometric analyses of the spatial arrangements of neurons and glia in postmortem cerebral cortex specimens has been developed and applied to both control subjects and schizophrenic patients. The data suggest that the anterior cingulate cortex of schizophrenic patients may contain domains or aggregates of neurons, particularly in layer II, which are smaller in size and separated by wider distances than those observed in the control group. Verification of the inferences made from the computer-generated data has been obtained by direct microscopic visualization and measurement of neuronal aggregates of layer II in Nissl-stained cingulate specimens from the control and schizophrenic groups. Statistical correction of the data, using multivariate statistics, for effects of age, hypoxia, postmortem interval, fixation, and neuroleptic exposure does not eliminate the differences in size and separation of neuronal aggregates in layer II of schizophrenic patients. The possible relevance of these findings to our understanding of schizophrenic symptomatology is discussed.

Somatostatin and neuropeptide Y are unaltered in the amygdala in schizophrenia

Although a biochemical abnormality has been postulated in the etiology of schizophrenia, evidence supporting this hypothesis has been conflicting. Because of the presence of somatostatin-like immunoreactivity (SLI) in limbic system nuclei of the brain, we examined postmortem concentrations of SLI in patients dying with schizophrenia and in normal controls. Concentrations of SLI in Brodmann cortical area 38, hippocampus, caudate, putamen, nucleus accumbens, and both segments of the globus pallidus were not significantly different from controls. In addition, we examined both SLI and neuropeptide-Y-like immunoreactivity (NPYLI) in subnuclei of the amygdala and the substantia innominata. There were no significant alterations in either neuropeptide as compared with controls.

Oxytocin in Alzheimer's disease: postmortem brain levels

Oxytocin (OXY) injected into the hippocampus is reported to interfere with the formation of memory in experimental animals. Memory impairment is one of the distinguishing features of Alzheimer's disease. We have studied OXY immunoreactivity in postmortem brain tissue from 12 cases of histologically confirmed Alzheimer's disease and 13 controls. OXY concentration was increased 33% in the hippocampus and temporal cortex of Alzheimer brains (p less than 0.05), but normal in all other regions examined. Elevated hippocampal OXY levels may contribute to the memory disturbance associated with Alzheimer's disease.

Alzheimer's disease: low cerebral somatostatin levels correlate with impaired cognitive function and cortical metabolism

Somatostatin-like immunoreactivity in Alzheimer CSF was significantly lower than in that from age-matched controls. The degree of reduction correlated with indices of intellectual impairment and decline in cortical glucose utilization as determined by PET. There was a close association between reduction in CSF somatostatin and glucose hypometabolism in the parietal lobe. In postmortem cortical tissue from Alzheimer patients, somatostatin levels were lower in posterior parietal but not in anterior frontal cortex. Loss of somatostatin-containing neurons, especially in the parietal association cortex, may be a critical determinant for Alzheimer dementia.

Human brain dopamine receptors in children and aging adults

Since spontaneous oral dyskinesias are more prevalent in the elderly, and since these movements may be controlled by the balance of brain dopamine D1 and D2 dopamine receptors, we measured the densities of these receptors in 247 postmortem brain striata. In childhood, the densities of D1 and D2 dopamine receptors in the brain striatum rise and fall together. After age 20 years, D1 receptors disappear at 3.2% per decade while D2 receptors disappear at about 2.2% per decade. Overall, therefore, the D1/D2 ratio falls with age. Since perioral motion in rats is dominated by a high D1/D2 ratio, the observed decline in the human D1/D2 ratio with age suggests that the perioral control mechanisms for humans and rats may be different.

Morphologic and histochemical characteristics of a spared subset of striatal neurons in Huntington's disease

We have previously found that a biochemically distinct subset of neurons, containing nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d), is selectively resistant to the degenerative process that affects the striatum in Huntington's disease (HD). We report the morphologic and histochemical characteristics of these striatal neurons and their distribution with respect to the histochemical compartments as defined by acetylcholinesterase (AChE) activity. Sections of striatum were stained histochemically for NADPH-d and AChE and immunocytochemically for somatostatin and neuropeptide Y-like immunoreactivity. The diaphorase end-product was contained within medium-sized neurons which corresponded morphologically to a category of aspiny interneurons. Combined techniques showed that NADPH-d, somatostatin, and neuropeptide Y coexisted within the same neurons in controls and patients with HD. The density of these neurons was greater in the ventral putamen and the nucleus accumbens than in the remainder of the striatum. The distinctive AChE pattern of high and low enzyme activity was altered in HD. The AChE-rich matrix zone was markedly reduced in size, while the total area of zones of low enzyme activity was not different from that found in control striatum. The relation between these AChE chemical compartments and the distribution of preserved diaphorase neurons remained intact; NADPH-d neurons were predominantly observed in the matrix zone.

Vasopressin in Alzheimer's disease: a study of postmortem brain concentrations

Vasopressin (AVP) and its analogues are reported to improve learning- and memory-related performance in experimental animals, and perhaps also in humans. Memory impairment is a clinical hallmark of the dementing disorder, Alzheimer's disease. We have examined AVP concentrations in postmortem brain tissue from 12 patients with histologically confirmed Alzheimer's disease and 13 control subjects. AVP was measured by a highly specific and sensitive radioimmunoassay, validated by parallel inhibition curves and high-performance liquid chromatography. Alzheimer brains had either normal or slightly increased AVP levels in the neocortex, which does not have AVP cell bodies. Significant reductions in AVP content were found in the hippocampus, nucleus accumbens, and globus pallidus interna. Levels were normal in all other regions studied. Abnormalities of the brain vasopressin system may contribute to the memory deficit associated with Alzheimer's disease.

Topography of enkephalin, substance P and acetylcholinesterase staining in Huntington's disease striatum

The distribution of Met-enkephalin (Enk) and substance P (SP) was examined in the striatum of Huntington's disease (HD) patients using immunoperoxidase techniques. Both Enk- and SP-like immunoreactivities (ir) were strikingly diminished in the dorsal caudate nucleus and putamen, while patchy staining persisted in the ventral putamen and nucleus accumbens. This was in sharp contrast to the patch-matrix pattern of acetylcholinesterase (AChE) staining which persisted throughout the entire striatum in HD. The regional loss of Enk- and SP-ir parallels the pattern of neuronal depletion in HD. The disparity between AChE staining and Enk- and SP-ir in HD suggests that AChE-positive neurons or fibers are resistant to the destructive process in areas where intrinsic neuronal populations are depleted.

A postmortem study of amino acid neurotransmitters in Alzheimer's disease

Concentrations of putative neurotransmitter amino acids were measured in postmortem brains from 10 patients with Alzheimer's disease and 10 controls. Glutamate, aspartate, taurine, gamma-aminobutyric acid (GABA), and alanine levels were examined in 9 cortical regions, hippocampus, thalamus, and basal ganglia using high-performance liquid chromatography with electrochemical detection. There were no significant alterations in aspartate, taurine, or alanine levels in any of the regions examined. Widespread significant reductions in cortical GABA concentrations were observed in the Alzheimer's brains, with the largest decreases in the temporal lobe. Overall values for glutamate concentrations in temporal and frontal cortices showed a significant 12% reduction in Alzheimer's brains, but the only individual cortical region showing a significant reduction in glutamate was the inferior temporal gyrus. These results suggest that gamma-aminobutyric acidergic neurons in Alzheimer's cerebral cortex may be selectively vulnerable to the disease process.

Widespread reduction of somatostatin-like immunoreactivity in the cerebral cortex in Alzheimer's disease

Although several studies have documented reduced concentrations of somatostatin-like immunoreactivity (SLI) in the cerebral cortex in Alzheimer's disease, there is controversy concerning the extent and importance of these changes. We measured SLI in brains obtained post mortem from 12 patients with pathologically confirmed Alzheimer's disease and from 13 neurologically normal controls. All major cortical and subcortical regions were examined. Widespread reductions of SLI in Alzheimer's disease cerebral cortex were found, with the most profound changes seen in temporal lobe; but there also were major reductions in both the frontal and occipital cortex. There were no significant reductions in subcortical regions. Characterization of SLI by high-pressure liquid chromatography showed no significant difference in profiles between Alzheimer's disease and control frontal cortex. These results suggest that the reduction in somatostatin immunoreactivity in Alzheimer's disease may be caused by degeneration of intrinsic somatostatin cortical neurons.

Gilles de la Tourette's syndrome. A postmortem neuropathological and immunohistochemical study

Immunocytochemical studies of the human forebrain have shown that enkephalin-like, dynorphin-like and substance-P-like immunoreactivity (respectively ELI, DLI, and SPI) normally present in unique pattern (now termed woolly fibers) in the globus pallidus and substantia nigra, in which their concentration is at its densest. Quantitative determinations moreover indicate that the levels of all 3 peptides are higher in the globus pallidus and substantia nigra than in any other region of the brain. We report here the distribution of immunoreactivity of these 3 peptides in the brain of a patient showing the typical clinical manifestations of Gilles de la Tourette's syndrome (TS); a disease for which no characteristic or consistent neuropathological features have been discerned. In the case described here neuropathological examination by means of the usual histopathological methods showed no abnormalities to which the patient's illness could be ascribed. ELI- and SPLI-positive woolly fibers were densely stained and of normal distribution. DLI-staining was, however, considerably less dense throughout the brain than normal. The most striking finding was the total absence of DLI-positive woolly fibers in the dorsal part of the external segment of the globus pallidus; the ventral pallidum showed very faint staining. These observations, which indicate a decrease of dynorphin in striatal fibers projecting to the globus pallidus, are, to our knowledge, the first evidence of a distinct pathological change in the brain in TS.

Elevated postmortem monoamine oxidase B activity in the caudate nucleus in Huntington's disease compared to schizophrenics and controls

Activity (Vmax) of monoamine oxidase (MAO) B in necropsy samples from the head of the caudate nucleus was 260% higher in patients dying with Huntington's disease (HD) than in controls (P less than 0.05). No differences in MAO A enzyme kinetics were found. MAO B, but not MAO A, was increased (26%) in the frontal cortex from patients dying with HD compared to control subjects. MAO A and B kinetics in caudate nucleus and frontal cortex from a group of schizophrenics did not differ from controls. Postmortem delay, the effect of neuroleptics, or nonspecific degeneration artifacts did not explain these findings. It is suggested that the increase in MAO B activity in the caudate nucleus may reflect neurochemical changes that are responsible for the choreiform movements of Huntington's disease. Lower cortical MAO B activity in the schizophrenic group may reflect the effects of neuroleptics.

Neuropeptide Y immunoreactivity is reduced in cerebral cortex in Alzheimer's disease

Neuropeptide Y is a 36-amino acid peptide that is found in high concentrations in cerebral cortex and is contained in cortical neurons. We measured concentrations of this peptide in postmortem tissue from patients with Alzheimer's disease and controls using a sensitive and specific radioimmunoassay. High-performance liquid chromatography showed that more than 95% of immunoreactivity co-migrated with synthetic standards in both Alzheimer's disease and control frontal cortex. Significant reductions in neuropeptide Y-like immunoreactivity were found in eleven cortical regions, the hippocampus, and the locus ceruleus. The regions particularly affected included the temporal lobe, frontal lobe, and occipital cortex. As neuropeptide Y is co-localized with somatostatin in a considerable proportion of cortical neurons, the loss of immunoreactivity may in part reflect degeneration of these neurons. Further study of the selective vulnerability of these neurons in Alzheimer's disease cortex may provide clues to the nature of the underlying disease process.

Optimization of freezing, storage, and thawing conditions for the preparation of metabolically active synaptosomes from frozen rat and human brain

Samples of rat and human cerebral cortex were frozen, stored, and thawed under a variety of conditions to define further the optimal procedure for storing human brain samples for subsequent metabolic and functional studies that use incubated synaptosomes. Tissue samples were best preserved by immersing them in isotonic sucrose prior to slow freezing, but there was no advantage in first chopping up the material. High concentrations of sucrose, rather than exerting a cryoprotective effect, were detrimental to subsequent synaptosomal performance (oxygen uptake, K+ accumulation, stimulus-induced release of amino acid neurotransmitters). However, good activity was observed in preparations from rat brain frozen in the absence of fluid. This result was confirmed by studies on the uptake of gamma-aminobutyrate (GABA) into an osmotically sensitive compartment in synaptosomes prepared from frozen human autopsy material transshipped from the brain tissue collection ("brain bank") at Harvard Medical School, MA, USA, to Sydney, Australia. Although activity was slowly lost over a 3-mo period in rat tissue samples stored at -20 degrees C, there was little or no such loss at -70 degrees C.

Somatostatin-28(1-12)-like immunoreactivity is reduced in Alzheimer's disease cerebral cortex

A deficiency in somatostatin is the most consistently described neurochemical alteration in Alzheimer's disease (AD) attributable to intrinsic cortical neurons. Somatostatin-28 (SOM-28), an N-terminal-extended form of somatostatin, can be cleaved to form somatostatin-28(1-12)(SOM-28(1-12) ) and somatostatin-14 (SOM-14). We have measured concentrations of SOM-28(1-12)-like immunoreactivity in 8 cortical regions from 12 patients with AD and 13 controls. Significant reductions (P less than 0.001) were found in all cortical regions examined with the largest decrease in temporal lobe. Reductions were significantly correlated with decreases in somatostatin-14-like immunoreactivity in the same regions. The similar reductions of two prosomatostatin-derived peptides in AD cerebral cortex supports the contention that decreased somatostatin immunoreactivity in AD is caused by a degeneration of somatostatin cortical neurons and terminals.

Distribution of the molecular forms of acetylcholinesterase in human brain: alterations in dementia of the Alzheimer type

Acetylcholinesterase (AChE), the enzyme that degrades acetylcholine, is a heterogeneous enzyme that can be separated into multiple molecular forms. A tetrameric membrane-bound form (G4) and a monomeric soluble form (G1) are the two predominant enzyme species in mammalian brain. The distribution of AChE molecular forms was defined by sucrose density gradients of 11 anatomical regions of postmortem brains from 10 patients with dementia of the Alzheimer type (DAT) and 14 nondemented controls of similar ages. The results demonstrate an overall loss of protein and enzyme activity in all areas of the DAT brains studied and a selective loss of the G4 form of AChE in Brodmann areas 9, 10, 11, 21, 22, and 40, and the amygdala. There was no change in the G4/G1 ratio in areas 17 and 20, in the hippocampus, or in the cerebellum. There was a high regional correlation of the G4/G1 ratios with published values for choline acetyltransferase activity but lower correlation with total AChE activity. We propose that there is a predominant loss of the G4 form of AChE in DAT and that this loss is correlated with the degeneration of presynaptic elements.

Brain choline acetyltransferase activity and neuropeptide Y concentrations in Alzheimer's disease

Choline acetyltransferase (ChAT) activity and neuropeptide Y (NPY) levels in post-mortem tissues from patients with histologically proven Alzheimer's disease were compared with age-matched neurologically normal control individuals. Despite the high NPY concentrations in human cerebral cortex, no significant abnormalities were found. However, ChAT activity was reduced throughout the cortex, without a relationship to areas of functional deficit, as previously identified using fluorodeoxyglucose. These results lend further support to the concept of Alzheimer's disease as a highly selective neurodegenerative disorder.

Quantitative cytoarchitectural studies of the cerebral cortex of schizophrenics

Quantitative morphometric determinations of neuronal and glial density, neuron-glia ratios, and neuronal size were performed in the prefrontal, anterior cingulate, and primary motor cortex of ten controls and ten schizophrenics diagnosed by Feighner criteria under blind conditions to assess whether neuronal degeneration had occurred. Stepwise multiple regression and multiple classification analyses were used to evaluate the effect of potential confounding variables such as age, postmortem interval, fixation, hypoxia, and neuroleptic exposure on the measures studied. The neuronal density was significantly lower in layer VI of the prefrontal, layer V of the cingulate, and layer III of motor cortex. There was also a trend toward fewer neurons in most layers of both prefrontal and motor cortex, although by discriminant analysis this generalized pattern was significant only for the prefrontal area. The glial density also tended to be lower throughout most layers of all three cortical regions. There were no differences in the neuron-glia ratios or neuronal size between the two groups. The data do not support the presence of neuronal degeneration in schizophrenic cortex as it is conventionally described by neuropathologists, but do suggest the possibility that cytoarchitectural variations in cortical structure might exist in this group of schizophrenics.

HPLC with electrochemical detection to measure chlorpromazine, thioridazine and metabolites in human brain

Thirteen phenothiazine compounds were separated chromatographically using high performance liquid chromatography with coulometric electrochemical detection. These could be extracted from brain tissue using direct homogenization in tetrahydrofuran followed by one centrifugation, evaporation of supernatant and reconstitution in water. Fluphenazine was used as the internal standard. The absolute lower limit of detection was approximately 50 pg/mg wet tissue, and recovery rates for most standards added to brain homogenates were greater than 85%. Chromatograms from patients receiving chlorpromazine (600 mg) and thioridazine (600 mg) are shown and endogenous brain levels quantified. The results are discussed with respect to their relevance in schizophrenic research.

Neuropathological classification of Huntington's disease

In postmortem brain specimens from 163 clinically diagnosed cases of Huntington's disease (HD) the striatum exhibited marked variation in the severity of neuropathological involvement. A system for grading this severity was established by macroscopic and microscopic criteria, resulting in five grades (0-4) designated in ascending order of severity. The grade correlates closely with the extent of clinical disability as assessed by a rating scale. In five cases of clinically diagnosed HD there were no discernible neuropathological abnormalities (grade 0), suggesting that the anatomical changes lag behind the development of clinical abnormalities. In eight cases, neuropathological changes could only be recognized microscopically (grade 1). The earliest changes were seen in the medial paraventricular portions of the caudate nucleus (CN), in the tail of the CN, and in the dorsal part of the putamen. Counts of neurons in the CN reveal that 50% are lost in grade 1 and that 95% are lost in grade 4; astrocytes are greatly increased in grades 2-4. These studies indicate that analyses of the CN in grade 4 would reflect mainly its astrocytic composition with a component of remote neurons projecting to the striatum. Because of the relative preservation of the lateral half of the head of the CN in grades 1-2, these regions would reflect early cellular and biochemical changes in HD.

Selective sparing of a class of striatal neurons in Huntington's disease

A distinct subpopulation of striatal aspiny neurons, containing the enzyme nicotinamide adenine dinucleotide phosphate diaphorase, is preserved in the caudate nucleus in Huntington's disease. Biochemical assays confirmed a significant increase in the activity of this enzyme in both the caudate nucleus and putamen in postmortem brain tissue from patients with this disease. The resistance of these neurons suggests that the gene defect in Huntington's disease may be modifiable by the local biochemical environment. This finding may provide insight into the nature of the genetically programmed cell death that is a characteristic of the disease.

Catecholamine metabolites and cyclic nucleotides in cerebrospinal fluid in dementia of Alzheimer type

Three, 4-dihydroxyphenylacetic acid (DOPAC); 3-methoxy, 4-hydroxyphenylacetic acid (HVA); 3-methoxy; 4-hydroxyphenylglycol (MHPG); adenosine 3', 5'-cyclic monophosphate (cyclic AMP); and guanosine 3', 5'-cyclic monophosphate (cyclic GMP) were measured in cerebrospinal fluid (CSF) of patients with dementia of Alzheimer type (DAT) and controls. DOPAC levels were lower and HVA levels were higher in DAT patients than in controls. In the most rostral fractions of CSF from DAT patients there was a negative correlation between DOPAC and cyclic AMP levels. In addition, patients with onset of DAT symptoms before the age of 65 had lower DOPAC levels, a higher HVA/DOPAC ratio, and higher cyclic nucleotide levels than patients with late onset of DAT. By combining DOPAC and cyclic AMP levels, we could clearly distinguish these two groups.

Reduced numbers of somatostatin receptors in the cerebral cortex in Alzheimer's disease

Somatostatin receptor concentrations were measured in patients with Alzheimer's disease and controls. In the frontal cortex (Brodmann areas 6, 9, and 10) and temporal cortex (Brodmann area 21), the concentrations of somatostatin in receptors in the patients were reduced to approximately 50 percent of control values. A 40 percent reduction was seen in the hippocampus, while no significant changes were found in the cingulate cortex, postcentral gyrus, temporal pole, and superior temporal gyrus. Scatchard analysis showed a reduction in receptor number rather than a change in affinity. Somatostatin-like immunoreactivity was significantly reduced in both the frontal and temporal cortex. Somatostatin-like immunoreactivity was linearly related to somatostatin-receptor binding in the cortices of Alzheimer's patients. These findings may reflect degeneration of postsynaptic neurons or cortical afferents in the patients' cerebral cortices. Alternatively, decreased somatostatin-like immunoreactivity in Alzheimer's disease might indicate increased release of somatostatin and down regulation of postsynaptic receptors.

The effects of a single acute dose of dexamethasone on monoamine and metabolite levels in rat brain

Twenty male Sprague-Dawley rats were injected intraperitoneally with either 20 micrograms of dexamethasone or an equivalent volume of saline. The rats were then sacrificed at either one or four hours after the injections and their brains analyzed for monoamine and metabolite content using High Performance Liquid Chromatography with Electrochemical Detection. Significant effects were seen in dopaminergic and serotonergic systems, but these effects varied depending on the area of rat brain studied. Significant increases in dopamine (DA) levels were seen in the hypothalamus and nucleus accumbens of the dexamethasone treated rats when compared with saline treated rats. There was no significant effect of dexamethasone on DA levels in frontal or striatal brain areas. In the dexamethasone treated rats a significant increase in serotonin (5-HT) was observed in the hypothalamus; a significant decrease in 5-HT was observed in the frontal cortex. Biological and clinical implications of these findings are discussed.

Quinolinic acid phosphoribosyltransferase in human and rat brain: activity in Huntington's disease and in quinolinate-lesioned rat striatum

Quinolinic acid (QUIN) is an excitotoxic compound which is present in rat and human brain and has been hypothetically linked to neurodegenerative disorders including Huntington's disease (HD). We have examined the biochemistry of QUIN by measuring the activity of its degradative enzyme QUIN phosphoribosyltransferase (QPRT) in post-mortem samples of human brain from normal and HD subjects, and in the striata of rats injected intrastriatally with QUIN. In normal human brain, QPRT activity was highest in the caudate nucleus and substantia nigra, less in the thalamus, hypothalamus, frontal cortex and hippocampus and lowest in the spinal cord and cerebellum. QPRT activity in HD caudate tended to be higher than control, the respective values (mean +/- S.E.M., n = 9 for each group) being 365.7 +/- 52.5 and 242.0 +/- 50.8 fmol/h/mg protein (0.1 greater than P greater than 0.05, t-test); values of enzyme activity in the putamen were similar between normal and HD groups. Kinetic analyses indicated that the Km values for QUIN and its co-substrate phosphoribosylpyrophosphate (PRPP) were similar in normal and HD caudate, but Vmax values were elevated in HD caudate. Rat striatal QPRT activity was increased in QUIN-injected striata, and when expressed as a percentage of the contralateral side it was 163.6% at 2 days, 344.4% at 14 days and 198.8% at 7 months post-injection. Kinetic analyses in the 7-month QUIN-injected group showed an increase of Vmax but no change of Km values for QUIN or PRPP. The results indicate that QPRT activity increases in response to specific neurodegenerative events.(ABSTRACT TRUNCATED AT 250 WORDS)

Regional mitochondrial respiratory activity in Huntington's disease brain

This study investigated mitochondrial respiratory activity in Huntington's disease (HD) brain. Mitochondrial membranes from caudate and cortex of HD and non-HD autopsied brains were assayed for succinate oxidation, cytochrome oxidase activity, and cytochromes b, cc1, and aa3. There was a significant decrease in HD caudate mitochondrial respiration, cytochrome oxidase activity, and cytochrome aa3, whereas cytochromes b and cc1 were normal. These findings are consistent with the hypothesis that mitochondrial dysfunction may contribute to the localized hypometabolism and progressive atrophy of the HD caudate.

Late onset of Huntington's disease

Twenty-five patients with late-onset Huntington's disease were studied; motor impairment appeared at age 50 years or later. The average age at onset of chorea was 57.5 years, with an average age at diagnosis of 63.1 years. Approximately 25% of persons affected by Huntington's disease exhibit late onset. A preponderance of maternal transmission was noted in late-onset Huntington's disease. The clinical features resembled those of mid-life onset Huntington's disease but progressed more slowly. Neuropathological evaluation of two cases reveal less severe neuronal atrophy than for mid-life onset disease.

Immunoreactive somatostatin-28(1-12) is increased in Huntington's disease

Somatostatin-28(1-12) concentrations were measured in Huntington's disease (HD) postmortem tissue using a specific radioimmunoassay. Concentrations of immunoreactive somatostatin-28(1-12) were significantly increased in the caudate and putamen but were unchanged in cortical areas A9 and A17. Since somatostatin-28(1-12) terminates with the amino acids Arg-Glu-OH, we examined whether this dodecapeptide compound might exert a neurotoxic effect. Injections of somatostatin-28(1-12) into rat striatum showed no evidence of histologic damage.

Acetylcholinesterase staining of the human amygdala

This paper describes in detail the acetylcholinesterase (AChE) staining characteristics of the normal human amygdaloid complex using fixed post-mortem brain tissue. It was shown that the differential AChE staining of the amygdala could be used to accurately delineate amygdaloid subdivisions macroscopically. Using the same staining method on the amygdala from brains previously frozen and stored at -70 degrees C resulted in a staining pattern similar to that seen using fixed tissue, despite numerous ice artifacts. It was concluded that this stain may be useful to researchers working on post-mortem human amygdala, particularly those involved in microdissecting this region for neurochemical analysis.

Cerebrospinal fluid neurotransmitter metabolites in neurologically normal infants and children

Significant inverse correlations with age were observed for free 3-methoxy-4-hydroxyphenylglycol (MHPG), 5-hydroxyindoleacetic acid (5-HIAA), and homovanillic acid (HVA) concentrations in CSF from 75 neurologically normal newborns, infants, and children aged 1 day to 10 years. The concentration of free MHPG decreased rapidly in early neonatal life and was reduced to near adult levels by 8 to 9 months of age. Adult levels of 5-HIAA were observed at about 4 years of age whereas HVA concentrations were still above adult levels at 10 years of age. Data from 0- to 1-month-old premature (28 to 32 weeks of gestation) and full-term (37 weeks of gestation) infants revealed marked changes in HVA and 5-HIAA concentrations which were related to postconceptional rather than postnatal age. This study demonstrates a previously undetected age effect on CSF MHPG concentration during the neonatal period and provides valuable normal data that are necessary for the interpretation of CSF monoamine metabolites in infants and children with hyperphenylalaninemia and other neurologic disease involving monoamine neurotransmitters.

Serotonin and 5-hydroxyindoleacetic acid in CSF. Difference in Parkinson's disease and dementia of the Alzheimer's type

Serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels were measured in the sixth, 13th, and 20th milliliters of CSF in patients with dementia of the Alzheimer's type (DAT) and Parkinson's disease (PD), and in an aliquot of CSF in controls. In patients with PD there was a positive correlation between 5-HT and 5-HIAA levels in the 20th milliliter of CSF, while in patients with DAT there was a negative correlation of these levels in this CSF fraction. In patients with the senile form of DAT the 5-HIAA levels in the 20th milliliter of CSF were higher than in patients with PD. These results indicate differential involvement of the serotoninergic system in DAT and PD, and may lead to the development of a chemical marker for DAT.

Late-onset Hallervorden-Spatz disease presenting as familial parkinsonism

We studied a 68-year-old man who died after 13 years of progressive dementia, rigidity, bradykinesia, mild tremor, stooped posture, slow and shuffling gait, dystonia, blepharospasm, apraxia of eyelid opening, anarthria, aphonia, and incontinence. At autopsy, he had generalized brain atrophy with large deposits of iron pigment in the globus pallidus, caudate, and substantia nigra. Axonal spheroids were found in the globus pallidus, substantia nigra, medulla, and spinal cord. The neurochemical analysis of the brain revealed marked loss of dopamine in the nigral-striatal areas, with relative preservation of dopamine in the limbic areas. This is the oldest case of familial Hallervorden-Spatz disease reported and the first with neurochemical analysis of the brain.

A corticosteroid/dopamine hypothesis for psychotic depression and related states

In recent years, considerable data have emerged that psychotic (delusional) depression is characterized by pronounced increases in hypothalamic-pituitary-adrenal (HPA) axis activity and positive responses to combined treatment with tricyclic antidepressants and antipsychotic (dopamine-blocking) agents. Recently, a number of observations in several species, including man, point to glucocorticoids' increasing dopamine activity in a variety of tissues and this effect is particularly marked in rat brain mesolimbic dopamine systems. We propose that glucocorticoids' enhancement of dopaminergic activity may explain the development of psychosis/delusions in the context of the depressive episode. Data in support of the hypothesis are presented and the identification of possible enzymatic risk factors are discussed. These interactions also have implications for understanding the biology of corticosteroid-induced psychoses in medical patients and some of the psychiatric complications of Cushing's Disease.

Somatostatin is increased in the nucleus accumbens in Huntington's disease

Concentrations of somatostatin-like immunoreactivity (SLI) are elevated in the basal ganglia in Huntington's disease. The present study confirms these findings and, in addition, shows that concentrations of SLI are significantly elevated in the nucleus accumbens (4.04 +/- 0.66 versus 1.69 +/- 0.21 ng/mg protein in controls). This area is relatively spared pathologically and shows little atrophy in Huntington's disease. Since many patients with Huntington's disease are treated with haloperidol, we studied the effects of this drug in rats. There was a dose-dependent reduction of SLI in striatum, parietal cortex, and hippocampus. The elevated concentrations of SLI in the basal ganglia in Huntington's disease, therefore, do not appear to result from haloperidol therapy.

Dexamethasone increases plasma free dopamine in man

In man, unconjugated plasma DA is normally undetectable or present in minute amounts. Twelve medication-free volunteers received a 1 mg dose of dexamethasone which produced pronounced increases of plasma free DA but not of other catecholamines. Mean plasma free dopamine levels after dexamethasone at 8 a.m. (155 +/- 102 pg/ml) and 4 p.m. (163 +/- 70 pg/ml) were significantly higher (p less than 0.001) than those at 8 a.m. (50 +/- 18 pg/ml) and 4 p.m. (42 +/- 7 pg/ml) before dexamethasone. Although the mechanism of increased dopaminergic activity after a dose of dexamethasone remains for future research, the data presented in this paper may explain the observations that corticosteroids lower prolactin levels and may induce psychiatric disturbances, as well as the finding that depressed patients with high postdexamethasone cortisol levels are frequently psychotic.

A post-mortem comparison of the cortical cholinergic system in Alzheimer's disease and Pick's disease

Assessment of neurochemical markers in the frontal cortex indicates that choline acetyltransferase is significantly decreased in Alzheimer's and Gerstmann-Straussler dementias but not in Pick's dementia. It therefore appears that the cholinergic innervation of the cortex from the basal forebrain is intact in Pick's disease. Cortical somatostatin was decreased only in Alzheimer's disease (AD), indicating that loss of somatostatin is not a constant feature in different forms of dementia. Muscarinic binding sites were unaltered in Pick's disease and Gerstmann-Straussler syndrome but were decreased in a subpopulation of AD patients. These data suggest that in some cases of AD a significant loss of cholinoceptive neurones in the cortex is evident.

Decreased catecholamine content caused by slicing of frozen human post mortem brain with an electric blade

A deleterious effect on dopamine and norepinephrine levels was observed in cortical Brodmann area 25 tissue dissected from mechanically cut coronal slices of frozen human brain. Catecholamine concentrations were found to be 10 (NE) and 7 (DA) fold higher in similar tissue dissected directly from the frozen hemisphere without cutting. A heat-related breakdown in endogenous catecholamine content is suspected. An alternative method is presented for cutting coronal slices of frozen human brain which involves much less heat and friction and provides slices with excellent morphological appearance.

Somatostatin is increased in the basal ganglia in Huntington disease

Huntington disease (HD) is an autosomal dominant hereditary disorder characterized by premature cell death, predominantly in the neostriatum. Decreased concentrations of several neurotransmitters and neuropeptides have been reported in the basal ganglia in Huntington disease. We now report that concentrations of radioimmunoassayable somatostatin are increased in extracts of the caudate (mean +/- standard error of the mean, ng/gm net weight; 247 +/- 24 versus 85 +/- 11), putamen (275 +/- 48 versus 74 +/- 11), external globus pallidus (100 +/- 10 versus 27 +/- 6), and internal globus pallidus (108 +/- 21 versus 21 +/- 8) in the disease. The concentrations of immunoreactive substance P measured in the same extracts were markedly reduced in caudate (mean +/- standard error of the mean, pmol/gm wet weight; 25 +/- 3 versus 109 +/- 20), putamen (28 +/- 7 versus 88 +/- 28), external globus pallidus (39 +/- 9 versus 196 +/- 62), and internal globus pallidus (60 +/- 17 versus 263 +/- 39), as well as in both subdivisions of the substantia nigra. Gel permeation chromatography and high-performance liquid chromatography showed radioimmunoassayable somatostatin to include peptides with physicochemical properties of the tetradecapeptide somatostatin and larger substances, including somatostatin-28-like material. A single peak of immunoreactive substance P corresponding to synthetic substance P was found by high performance liquid chromatography. These results suggest that immunoassayable somatostatin-containing neuronal elements in the neostriatum and globus pallidus in Huntington disease are affected differentially by the disease process from neurons that contain immunoreactive substance P.

Maternal transmission in Huntington's disease

The effect of maternal transmission on age at onset of Huntington's disease (HD) was examined in 100 unrelated pedigrees. The age at which abnormal movement disorder first appeared could be estimated in 238 patients. More than twice as many of the late-onset cases (age 50 or later) inherited the HD gene from an affected mother than from an affected father. Affected offspring of late-onset females also had late-onset disease while those of late-onset males had significantly earlier ages of onset. This pattern of maternal inheritance suggests a model where the late-onset form of HD is related to a maternally transmitted factor such as the mitochondrion and its genome.

Lack of cholinergic deficit in the neocortex in Pick's disease

Choline acetyltransferase activity was decreased in the frontal cortex in Alzheimer's and Gerstmann-Straussler dementias but not in Pick's disease. Cortical somatostatin was only decreased in Alzheimer's dementia. Postsynaptic muscarinic binding sites appeared to be decreased in a subpopulation of Alzheimer's patients. Our data indicate that a loss of cholinergic innervation of the cortex is not common to all dementias.

Decreased pyruvate dehydrogenase complex activity in Huntington and Alzheimer brain

The activity of the pyruvate dehydrogenase complex (PDHC) was reduced in affected areas of brain from patients with Huntington disease (caudate, putamen) and Alzheimer disease (frontal cortex) where choline acetyltransferase (CAT) activity was low. PDHC was also deficient in an area (Huntington hippocampus) where CAT was not significantly reduced. The activity of fumarase, an inner mitochondrial marker, was normal in all areas examined. The activities of PDHC and CAT correlated well in caudate, putamen, and amygdala but not in hippocampus or frontal cortex. Both total activity and activation of PDHC were below normal in fibroblasts from 4 patients with C-21 trisomy Down syndrome, who are at very high risk to develop Alzheimer disease. However, no abnormality of PDHC was detected in Huntington or Alzheimer fibroblasts. Deficiency of PDHC may play a role in the pathophysiology of Huntington and Alzheimer diseases, although it does not appear to be a primary defect. Loss of tissue oxidative capacity may relate to the reduction in cerebral metabolic rate and blood flow which are characteristic of many dementing illnesses.

Stability of monoamine metabolites in human cerebrospinal fluid

Concentrations of 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were measured in human lumbar cerebrospinal fluid following storage at room temperature and 4 degrees C for intervals up to 72 hours. These monoamine metabolites were quantitated using a high-performance liquid chromatographic-electrochemical detector technique. No significant difference could be detected in any of the three metabolites stored at room temperature for up to 48 hours. Addition of ascorbic acid to CSF had no measurable effect on the levels of HVA and 5-HIAA. Repeated thawing and freezing produced no detectable change in metabolite levels. The results indicate that these monoamine metabolites are stable at room temperature for up to 48 hours after lumbar puncture and that the addition of an antioxidant, such as ascorbic acid, is not necessary. The data also demonstrate that immediate refrigeration or freezing of samples is not required for maintenance of metabolite levels.

Dopamine and homovanillic acid concentrations in striatal and limbic regions of human brain

In an attempt to further define the dopaminergic nature of the limbic nucleus accumbens from the morphologically similar striatal caudate and putamen, the levels of dopamine (DA), homovanillic acid (HVA), and HVA/DA ratios, an index of dopamine turnover, were measured in these three structures of human brain. The levels of dopamine in the accumbens (2.49 ng/mg), caudate (2.39 ng/mg), and putamen (3.00 ng/mg) were similar. The homovanillic acid concentration in the accumbens (7.44 ng/mg) and putamen (6.54 ng/mg) were comparable, while its concentration was considerably lower in the caudate (3.61 ng/mg). The most striking difference between the limbic accumbens and the striatum was observed in the HVA/DA ratio. This index of turnover was significantly higher in the accumbens (3.64) when compared to the caudate (1.80), and was 59% higher than that found in the putamen (2.53). The data provide evidence for differences in dopamine activity in the mesolimbic versus the nigrostriatal pathways.

Huntington chorea is not associated with hyperactivity of nigrostriatal dopaminergic neurons: studies in postmortem tissues and in rats with kainic acid lesions

We estimated dopamine release postmortem in the neostriatum of patients with Huntington disease (HD) and in controls. In HD, dopamine levels were unchanged in caudate and elevated in putamen, but homovanillic acid (HVA) and the ratio HVA:dopamine were unaltered in both nuclei. When rats were injected with kainic acid (an experimental model of HD), dopamine levels in striatum remained unchanged 2 to 30 days postoperatively; HVA and 3,4-dihydroxyphenylacetic acid (DOPAC) increased significantly from 2 to 18 days after injections but returned to normal levels later. These findings suggest that the nigrostriatal projection adapts to loss of striatal neurons that normally influence dopamine release and is not hyperactive in HD chorea.

Phenothiazine biphasic effect on dopamine concentrations in the basal ganglia of subhuman primates

Interpretation of data on the possible relationship between changes in endogenous putative transmitters and neuropsychiatric disorders may be altered by the use of neuroleptic agents. As one approach to this problem, we attempted to simulate the situation in man by measuring the changes in dopamine in basal ganglia of monkeys during the chronic (20 months) administration of an antipsychotic phenothiazine. Unexpectedly, a biphasic response was obtained: dopamine increased after 2 months but was markedly reduced after 20 months. Perhaps, dyskinesia is related to this biphasic effect of the antipsychotic phenothiazines.

In vitro synthesis of human brain proteins including tubulin and actin by purified postmortem polysomes

Polysomes were prepared from human brain tissue 2-6 h postmortem; the polysomes were active in a cell-free protein synthesis system containing rabbit reticulocyte factors. Protein synthesis was totally dependent upon added MgCl2, ATP, the reticulocyte factor fraction, and the human polysome fraction. Human brain proteins synthesized in the presence of L-[35S]methionine were analyzed by one- and two-dimensional polyacrylamide gel electrophoresis. Over 250 proteins were synthesized and they extended in size up to 250,000 d; many of the most abundant native human brain proteins were synthesized, including tubulin and actin. It was shown that human brain alpha and beta tubulin and actin isomers synthesized in vitro from human postmortem polysomes have the same apparent molecular weights and isoelectric points as the corresponding proteins synthesized by rat polysomes from fresh cortices. The corresponding tubulin and actin synthesized by human and rat brain polysomes also yield the same radioactive methionine-containing peptides after digestion with Staphylococcus aureus V8 protease. These analyses indicate that postmortem polysomes contain active messenger RNA which can direct the partial and/or complete synthesis of actin and tubulin subunits and other human brain proteins.

The preparation of biologically active messenger RNA from human postmortem brain tissue

Messenger RNA (mRNA) was extracted from human postmortem brain tissue by alkaline phenol extraction of polysomes followed by oligo (dT)-cellulose chromatography. The mRNA preparations stimulated protein synthesis in a cell-free system containing wheat germ homogenate. The products of protein synthesis were analyzed by one- and two-dimensional gel electrophoresis. These analyses indicated that numerous polypeptides, including tubulin subunits and actin isomers, were synthesized by the human mRNA. The molecular weight range of polypeptides synthesized by human mRNA fractions from two brain specimens were identical, and analysis by two-dimensional gel electrophoresis indicated qualitatively similar products. The yield of mRNA extracted per gram of human tissue was less than the yield obtained with rat forebrains from animals sacrificed immediately before brain removal and mRNA purification. A decrease in the amount of polysomes isolated from human tissue relative to rat brain tissue was a major factor contributing to the low yield. The molecular weight distribution of polypeptides synthesized by human and rat brain mRNA fractions in wheat germ homogenate was similar; thus, there was no indication for selective breakdown or inactivation of high molecular weight mRNA species in the human tissue. Our studies indicate that it is possible to utilize postmortem tissue for molecular biological investigations of human brain mRNA.