Consensus on minimal criteria of clinical and neuropathological diagnosis of schizophrenia and affective disorders for post mortem research. Report from the European Dementia and Schizophrenia Network (BIOMED I)

Subcomponents of brain T2* relaxation in schizophrenia, bipolar disorder and siblings: A Gradient Echo Plural Contrast Imaging (GEPCI) study

Investigating brain tissue T2* relaxation properties in vivo can potentially guide the uncovering of neuropathology in psychiatric illness, which is traditionally examined post mortem. We use an MRI-based Gradient Echo Plural Contrast Imaging (GEPCI) technique that produces inherently co-registered images allowing quantitative assessment of tissue cellular and hemodynamic properties. Usually described as R2* (=1/T2*) relaxation rate constant, recent developments in GEPCI allow the separation of cellular-specific (R2*C) and hemodynamic (BOLD) contributions to the MRI signal decay. We characterize BOLD effect in terms of tissue concentration of deoxyhemoglobin, i.e. CDEOXY, which reflects brain activity. 17 control (CON), 17 bipolar disorder (BPD), 16 schizophrenia (SCZ), and 12 unaffected schizophrenia sibling (SIB) participants were scanned and post-processed using GEPCI protocols. A MANOVA of 38gray matter regions ROIs showed significant group effects for CDEOXY but not for R2*C. In the three non-control groups, 71-92% of brain regions had increased CDEOXY. Group effects were observed in the superior temporal cortex and the thalamus. Increased superior temporal cortex CDEOXY was found in SCZ (p=0.01), BPD (p=0.01) and SIB (p=0.02), with bilateral effects in SCZ and only left hemisphere effects in BPD and SIB. Thalamic CDEOXY abnormalities were observed in SCZ (p=0.003), BPD (p=0.03) and SIB (p=0.02). Our results suggest that increased activity in certain brain regions is part of the underlying pathophysiology of specific psychiatric disorders. High CDEOXY in the superior temporal cortex suggests abnormal activity with auditory, language and/or social cognitive processing. Larger studies are needed to clarify the clinical significance of relaxometric abnormalities.

Pitfalls and practicalities in collecting and banking human brain tissues for research on psychiatric and neulogical disorders

It is essential to examine brain materials for the understanding the cause and pathology of mental disorders. Recent methodological progress urges us to set up well qualified brain banks. Human tissue and Bio-banking is a complex field and the daily practice of brain banks needs to abide by several golden standards in order to avoid pitfalls in basic research: 1) A donor system in which informed consent is granted for the use of the samples for scientific research, including genetic analysis and access to medical records, 2) Rapid autopsy system, 3) Compatibility of protocols for procurement, management, handling and storage, 4) A generally accepted consensus on diagnostic criteria, 5) Quality control, 6) Abiding by local/international legal and ethical guidelines for work with human material, 7) Proper safety procedures. In the present review, the authors introduced the activities of European brain banks, and discussed on their current issues, and on the problems remain to be resolved.

How a neuropsychiatric brain bank should be run: a consensus paper of Brainnet Europe II

The development of new molecular and neurobiological methods, computer-assisted quantification techniques and neurobiological investigation methods which can be applied to the human brain, all have evoked an increased demand for post-mortem tissue in research. Psychiatric disorders are considered to be of neurobiological origin. Thus far, however, the etiology and pathophysiology of schizophrenia, depression and dementias are not well understood at the cellular and molecular level. The following will outline the consensus of the working group for neuropsychiatric brain banking organized in the Brainnet Europe II, on ethical guidelines for brain banking, clinical diagnostic criteria, the minimal clinical data set of retrospectively analyzed cases as well as neuropathological standard investigations to perform stageing for neurodegenerative disorders in brain tissue. We will list regions of interest for assessments in psychiatric disorder, propose a dissection scheme and describe preservation and storage conditions of tissue. These guidelines may be of value for future implementations of additional neuropsychiatric brain banks world-wide.

A molecular study of hippocampus in dogs with convulsion during canine distemper virus encephalitis

In this study, we have investigated the expression of the nuclear transcription factor (c-Fos, NFkB), growth factors (nerve growth factor--NGF, brain-derived neurotrophic factor--BDNF), peptides (enkephalin, galanin) and glutamate transporter (AA 504-523 rat EAAC1) in 6 dogs sacrificed immediately after seizure attack during encephalomyelitis due to canine distemper virus (CDV) (as assessed by clinical examination, RT-PCR and viral RNA detection either in blood or brain tissue and CDV immunohistochemistry in brain slices). In all these CDV affected dogs, the observed neurological signs included untreatable seizures, leading to cluster seizure activity and status epilepticus. In the inter-ictal phase abnormal mentation, postural and gait deficits and sometimes involuntary movements such as myoclonus were recorded. The same investigation was carried out in 5 control dogs affected by different disorders, all characterized by the absence of seizures. Brains were dissected out immediately after euthanasia and fixed; sections collected from the dorsal hippocampus were processed for immunohistochemistry. By comparing hippocampus sections obtained from dog with and without seizure, the following regulations were observed. A strong up-regulation of glutamate transporter throughout the cell layers was found together with the onset of nuclear Fos and NFkB-IR in the pyramidal cell layer X. Among the investigated peptides, we observed a slight increase in enkephalinergic fibers and a strong up-regulation of mu-opioid receptors, whereas galanin-IR seemed to be weaker. Finally, both NGF and BDNF expression was strongly up-regulated. BDNF-IR was mainly localized in the apical dendrite in pyramidal neurons. To our knowledge, these data offer the first indication that molecular events described in experimental kindling also occur during spontaneous pathology in animal species sharing close similarities to human neuropathology.

Reliability of psychiatric diagnosis in postmortem research

BACKGROUND

Postmortem human brain research is an important approach for identifying the cellular, molecular, and genetic pathways involved in the pathophysiology of psychiatric disorders. One critical component in postmortem research is the reliability of psychiatric diagnoses used to define study cohorts. Finding reliable methods for assessing lifetime psychiatric diagnoses in subjects after death is extremely challenging.

METHODS

Two commonly used approaches were compared: psychiatric record reviews and postmortem family interviews. We hypothesized that these two methods would lead to more diagnostic agreement for subjects with schizophrenia than those with mood disorders. For 37 cases, psychiatric records were reviewed retrospectively using the Diagnostic Evaluation After Death, and family members were interviewed using the Structured Clinical Interview for DSM-IV.

RESULTS

Comparison of diagnoses derived from these two approaches generated an overall kappa coefficient of .67. Kappa coefficients for the schizophrenia cohort were .94, .68 for the major depressive disorder cohort, and .58 for the bipolar disorder cohort.

CONCLUSIONS

Thus, although it may be sufficient to establish the postmortem diagnosis of schizophrenia using one of the two methods, the best method for reaching an accurate postmortem diagnosis for mood disorders is more difficult to determine and requires further study.

The neuropathology of schizophrenia. A critical review of the data and their interpretation

Despite a hundred years' research, the neuropathology of schizophrenia remains obscure. However, neither can the null hypothesis be sustained--that it is a 'functional' psychosis, a disorder with no structural basis. A number of abnormalities have been identified and confirmed by meta-analysis, including ventricular enlargement and decreased cerebral (cortical and hippocampal) volume. These are characteristic of schizophrenia as a whole, rather than being restricted to a subtype, and are present in first-episode, unmedicated patients. There is considerable evidence for preferential involvement of the temporal lobe and moderate evidence for an alteration in normal cerebral asymmetries. There are several candidates for the histological and molecular correlates of the macroscopic features. The probable proximal explanation for decreased cortical volume is reduced neuropil and neuronal size, rather than a loss of neurons. These morphometric changes are in turn suggestive of alterations in synaptic, dendritic and axonal organization, a view supported by immunocytochemical and ultrastructural findings. Pathology in subcortical structures is not well established, apart from dorsal thalamic nuclei, which are smaller and contain fewer neurons. Other cytoarchitectural features of schizophrenia which are often discussed, notably entorhinal cortex heterotopias and hippocampal neuronal disarray, remain to be confirmed. The phenotype of the affected neuronal and synaptic populations is uncertain. A case can be made for impairment of hippocampal and corticocortical excitatory pathways, but in general the relationship between neurochemical findings (which centre upon dopamine, 5-hydroxytryptamine, glutamate and GABA systems) and the neuropathology of schizophrenia is unclear. Gliosis is not an intrinsic feature; its absence supports, but does not prove, the prevailing hypothesis that schizophrenia is a disorder of prenatal neurodevelopment. The cognitive impairment which frequently accompanies schizophrenia is not due to Alzheimer's disease or any other recognized neurodegenerative disorder. Its basis is unknown. Functional imaging data indicate that the pathophysiology of schizophrenia reflects aberrant activity in, and integration of, the components of distributed circuits involving the prefrontal cortex, hippocampus and certain subcortical structures. It is hypothesized that the neuropathological features represent the anatomical substrate of these functional abnormalities in neural connectivity. Investigation of this proposal is a goal of current neuropathological studies, which must also seek (i) to establish which of the recent histological findings are robust and cardinal, and (ii) to define the relationship of the pathological phenotype with the clinical syndrome, its neurochemistry and its pathogenesis.

Hormonal influences on brain ageing quality: focus on corticotropin releasing hormone-, vasopressin- and oxytocin-immunoreactive neurones in the human brain

In this paper we have investigated the distribution of corticotropin releasing hormone (CRH)-, vasopressin- and oxytocin-immunoreactive (IR) neurones in the paraventricular nucleus in the senile compared to the adult human brain. We found a higher number of CRH-IR neurones in senile compared to adult subjects. Vasopressin- and oxytocin-IR neurones were instead more weakly stained in the former compared to latter. These results support a hypothalamic involvement in promoting the higher activity of the hypothalamus-pituitary-adrenal axis and, thus, higher glucocorticoid plasma levels which have been described in the elderly.