Circadian dysregulation of clock genes: clues to rapid treatments in major depressive disorder.

Conventional antidepressants require 2-8 weeks for a full clinical response. In contrast, two rapidly acting antidepressant interventions, low-dose ketamine and sleep deprivation (SD) therapy, act within hours to robustly decrease depressive symptoms in a subgroup of major depressive disorder (MDD) patients. Evidence that MDD may be a circadian-related illness is based, in part, on a large set of clinical data showing that diurnal rhythmicity (sleep, temperature, mood and hormone secretion) is altered during depressive episodes. In a microarray study, we observed widespread changes in cyclic gene expression in six regions of postmortem brain tissue of depressed patients matched with controls for time-of-death (TOD). We screened 12 000 transcripts and observed that the core clock genes, essential for controlling virtually all rhythms in the body, showed robust 24-h sinusoidal expression patterns in six brain regions in control subjects. In MDD patients matched for TOD with controls, the expression patterns of the clock genes in brain were significantly dysregulated. Some of the most robust changes were seen in anterior cingulate (ACC). These findings suggest that in addition to structural abnormalities, lesion studies, and the large body of functional brain imaging studies reporting increased activation in the ACC of depressed patients who respond to a wide range of therapies, there may be a circadian dysregulation in clock gene expression in a subgroup of MDDs. Here, we review human, animal and neuronal cell culture data suggesting that both low-dose ketamine and SD can modulate circadian rhythms. We hypothesize that the rapid antidepressant actions of ketamine and SD may act, in part, to reset abnormal clock genes in MDD to restore and stabilize circadian rhythmicity. Conversely, clinical relapse may reflect a desynchronization of the clock, indicative of a reactivation of abnormal clock gene function. Future work could involve identifying specific small molecules capable of resetting and stabilizing clock genes to evaluate if they can rapidly relieve symptoms and sustain improvement.

Huntington's disease cerebrospinal fluid seeds aggregation of mutant huntingtin.

Huntington's disease (HD), a progressive neurodegenerative disease, is caused by an expanded CAG triplet repeat producing a mutant huntingtin protein (mHTT) with a polyglutamine-repeat expansion. Onset of symptoms in mutant huntingtin gene-carrying individuals remains unpredictable. We report that synthetic polyglutamine oligomers and cerebrospinal fluid (CSF) from BACHD transgenic rats and from human HD subjects can seed mutant huntingtin aggregation in a cell model and its cell lysate. Our studies demonstrate that seeding requires the mutant huntingtin template and may reflect an underlying prion-like protein propagation mechanism. Light and cryo-electron microscopy show that synthetic seeds nucleate and enhance mutant huntingtin aggregation. This seeding assay distinguishes HD subjects from healthy and non-HD dementia controls without overlap (blinded samples). Ultimately, this seeding property in HD patient CSF may form the basis of a molecular biomarker assay to monitor HD and evaluate therapies that target mHTT.

Absence of evidence for bornavirus infection in schizophrenia, bipolar disorder and major depressive disorder.

In 1983, reports of antibodies in subjects with major depressive disorder (MDD) to an as-yet uncharacterized infectious agent associated with meningoencephalitis in horses and sheep led to molecular cloning of the genome of a novel, negative-stranded neurotropic virus, Borna disease virus (BDV). This advance has enabled the development of new diagnostic assays, including in situ hybridization, PCR and serology based on recombinant proteins. Since these assays were first implemented in 1990, more than 80 studies have reported an association between BDV and a wide range of human illnesses that include MDD, bipolar disorder (BD), schizophrenia (SZ), anxiety disorder, chronic fatigue syndrome, multiple sclerosis, amyotrophic lateral sclerosis, dementia and glioblastoma multiforme. However, to date there has been no blinded case-control study of the epidemiology of BDV infection. Here, in a United States-based, multi-center, yoked case-control study with standardized methods for clinical assessment and blinded serological and molecular analysis, we report the absence of association of psychiatric illness with antibodies to BDV or with BDV nucleic acids in serially collected serum and white blood cell samples from 396 subjects, a study population comprised of 198 matched pairs of patients and healthy controls (52 SZ/control pairs, 66 BD/control pairs and 80 MDD/control pairs). Our results argue strongly against a role for BDV in the pathogenesis of these psychiatric disorders.

Altered expression of glutamate signaling, growth factor, and glia genes in the locus coeruleus of patients with major depression.

Several studies have proposed that brain glutamate signaling abnormalities and glial pathology have a role in the etiology of major depressive disorder (MDD). These conclusions were primarily drawn from post-mortem studies in which forebrain brain regions were examined. The locus coeruleus (LC) is the primary source of extensive noradrenergic innervation of the forebrain and as such exerts a powerful regulatory role over cognitive and affective functions, which are dysregulated in MDD. Furthermore, altered noradrenergic neurotransmission is associated with depressive symptoms and is thought to have a role in the pathophysiology of MDD. In the present study we used laser-capture microdissection (LCM) to selectively harvest LC tissue from post-mortem brains of MDD patients, patients with bipolar disorder (BPD) and from psychiatrically normal subjects. Using microarray technology we examined global patterns of gene expression. Differential mRNA expression of select candidate genes was then interrogated using quantitative real-time PCR (qPCR) and in situ hybridization (ISH). Our findings reveal multiple signaling pathway alterations in the LC of MDD but not BPD subjects. These include glutamate signaling genes, SLC1A2, SLC1A3 and GLUL, growth factor genes FGFR3 and TrkB, and several genes exclusively expressed in astroglia. Our data extend previous findings of altered glutamate, astroglial and growth factor functions in MDD for the first time to the brainstem. These findings indicate that such alterations: (1) are unique to MDD and distinguishable from BPD, and (2) affect multiple brain regions, suggesting a whole-brain dysregulation of such functions.

Urinary adenosine 3',5'-monophosphate in the switch process from depression to mania.

Marked elevations of urinary adenosine 3',5'-monophosphate occurred on the day of rapid switch from a depressed into a manic state in patients with manic-depressive illness. It is suggested that this increase might serve a trigger function for the process by which catecholamines are elevated during the manic phase of the illness.

Schizophrenia: dopamine beta-hydroxylase activity and treatment response.

Cerebrospinal fluid levels of dopamine beta-hydroxylase, found to be relatively constant over time in individual patients, were significantly lower in schizophrenic patients who became nonpsychotic during neuroleptic treatment than in those who remained psychotic. Dopamine beta-hydroxylase activity may delineate a subgroup of patients who have a dopamine-sensitive brain disorder.

Long-term treatment with lithium prevents the development of dopamine receptor supersensitivity.

Long-term treatment of rats with haloperidol produced an increased sensitivity to the locomotor and stereotypic effect of apomorphine. This behavioral dopaminergic supersensitivity was accompanied by increased binding of [3H] spiroperidol in the striatum. Rats treated concurrently with lithium and haloperidol failed to develop both behavioral sensitivity to apomorphine and increased striatal dopamine receptor binding. The ability of lighium to prevent recurrent manicdepressive episodes may be related, in part, to its ability to stabilize dopaminergic receptor sensitivity.

Central norepinephrine metabolism in affective illness: MHPG in the cerebrospinal fluid.

Concentrations of the norepinephrine metabolite 3-methoxy-4-hydroxyphenyl glycol in cerebrospinal fluid were measured by a gas chromatographic method in 34 patients with affective illness and in 44 controls. Concentrations of this metabolite in spinal fluid were significantly lower in depressed patients than in controls or manic patients. These low values may occur secondary to depressive phenomena such as reduced psychomotor activity, or they may reflect a primary change in norepinephrine metabolism in depressive illness.

Dialysis in schizophrenia: a double-blind evaluation.

Eight chronic schizophrenia patients completed a research program consisting of ten weekly sessions of active hemodialysis and ten weekly sessions of sham dialysis in a double-blind design. Previous reports of therapeutic efficacy were not substantiated. None of the patients improved during active dialysis; four patients worsened.

Lithium: effects on subjective functioning and morphine-induced euphoria.

The therapeutic usefulness of lithium in decreasing the euphoria and other symptoms associated with manic behavior and the hypothesis of a common final mechanism for elevations in mood have led to speculation that lithium may block the euphoria induced by drugs of abuse. In this study, lithium alone was antieuphoric in drug-free opiate addicts and, further, did not block morphine-induced euphoria.

Schizophrenia: elevated cerebrospinal fluid norepinephrine.

Concentrations of norepinephrine in cerebrospinal fluid are higher in schizophrenic patients, particularly in those with paranoid features, than in normal volunteer subjects of the same age. This observation supports recent reports of elevated concentrations of norepinephrine in specific brain areas adjacent to the cerebral ventricles of paranoid schizophrenic patients. Overflow of the amine from periventricular regions into the cerebrospinal fluid may reflect abnormally high release or diminished enzymatic destruction of norepinephrine in patients with schizophrenia.

Intravenous naloxone administration in schizophrenia and affective illness.

Fourteen schizophrenic patients and five patients with affective disorders were given naloxone (0.4 to 10 milligrams) or placebo intravenously in a double-blind fashion. Physicians' ratings of hallucinations, mannerisms and posturing, conceptual disorganization, psychosis, and mood did not change significantly. A single item, unusual thought content, improved significantly on the naloxone day compared to the placebo day. There was no improvement in mood in affectively ill patients rated either by themselves or by physicians. Naloxone did not markedly improve any patient studied, which suggests that the acute blockade of opiate receptors is not associated with global improvement in psychotic symptomatology.

Electrophysiological evaluation of extracellular spermine and alkaline pH on synaptic human GABAA receptors.

Polyamines have fundamental roles in brain homeostasis as key modulators of cellular excitability. Several studies have suggested alterations in polyamine metabolism in stress related disorders, suicide, depression, and neurodegeneration, making the pharmacological modulation of polyamines a highly appealing therapeutic strategy. Polyamines are small aliphatic molecules that can modulate cationic channels involved in neuronal excitability. Previous indirect evidence has suggested that polyamines can modulate anionic GABAA receptors (GABAARs), which mediate inhibitory signaling and provide a direct route to reduce hyperexcitability. Here, we attempted to characterize the effect that spermine, the polyamine with the strongest reported effect on GABAARs, has on human postmortem native GABAARs. We microtransplanted human synaptic membranes from the dorsolateral prefrontal cortex of four cases with no history of mental or neurological disorders, and directly recorded spermine effects on ionic GABAARs responses on microtransplanted oocytes. We show that in human synapses, inhibition of GABAARs by spermine was better explained by alkalization of the extracellular solution. Additionally, spermine had no effect on the potentiation of GABA-currents by diazepam, indicating that even if diazepam binding is enhanced by spermine, it does not translate to changes in functional activity. Our results clearly demonstrate that while extracellular spermine does not have direct effects on human native synaptic GABAARs, spermine-mediated shifts of pH inhibit GABAARs. Potential spermine-mediated increase of pH in synapses in vivo may therefore participate in increased neuronal activity observed during physiological and pathological states, and during metabolic alterations that increase the release of spermine to the extracellular milieu.

The fibroblast growth factor family and mood disorders.

While there has been a great deal of interest in the role of brain-derived neurotrophic factor (BDNF) in mood disorders and/or the mode of action of antidepressants, less is known about the role of other growth factors. This paper is focused on a group of growth factors, the fibroblast growth factor (FGF) family and their potential role in mood disorders.

Quantitative validation of immunofluorescence and lectin staining using reduced CLARITY acrylamide formulations.

The CLARITY technique enables three-dimensional visualization of fluorescent-labeled biomolecules in clarified intact brain samples, affording a unique view of molecular neuroanatomy and neurocircuitry. It is therefore, essential to find the ideal combination for clearing tissue and detecting the fluorescent-labeled signal. This method requires the formation of a formaldehyde-acrylamide fixative-generated hydrogel mesh through which cellular lipid is removed with sodium dodecyl sulfate. Several laboratories have used differential acrylamide and detergent concentrations to achieve better tissue clearing and antibody penetration, but the potential effects upon fluorescent signal retention is largely unknown. In an effort to optimize CLARITY processing procedures we performed quantitative parvalbumin immunofluorescence and lectin-based vasculature staining using either 4 or 8% sodium dodecyl sulfate detergent in combination with different acrylamide formulas in mouse brain slices. Using both confocal and CLARITY-optimized lightsheet microscope-acquired images, we demonstrate that 2% acrylamide monomer combined with 0.0125% bis-acrylamide and cleared with 4% sodium dodecyl sulfate generally provides the most optimal signal visualization amongst various hydrogel monomer concentrations, lipid removal times, and detergent concentrations.

Color blindness not closely linked to bipolar illness. Report of a new pedigree series.

A new pedigree series of bipolar manic-depressive patients admitted to the National Institute of Mental Health intramural research program was evaluated for linkage between bipolar illness and red-green color blindness, since previous studies had indicated that close linkage was generally present. Using family study methods, six informative pedigrees were investigated. Analysis was performed using a multigenerational procedure and taking into account variable penetrance. Close linkage could be definitively ruled out as a general finding. Bipolar and related illnesses are thus not generally transmitted by a single major gene close to the protan/deutan region of the human X-chromosome.

Serum calcium and magnesium levels in schizophrenia. II. Possible relationship to extrapyramidal symptoms.

The relationship between serum calcium and magnesium levels and neuroleptic-induced extrapyramidal symptoms (EPS) was studied in schizophrenic patients. The 16 patients in whom EPS developed had a significantly lower mean drug-free calcium level than the six patients in whom EPS did not develop. In patients in whom EPS developed, drug-free serum calcium and magnesium levels together correlated significantly with the neuroleptic dosage at which EPS first developed; lower calcium and magnesium values predicted EPS at lower dosages. We have previously shown that both serum calcium and magnesium levels were significantly lower during neuroleptic treatment than in the drug-free state. In this study, a similar trend was observed, but the calcium value tended to be, and the magnesium value was significantly lower at the onset of neuroleptic-induced EPS than during the mean of an entire pimozide trial.

Maldistribution of interstitial neurons in prefrontal white matter of the brains of schizophrenic patients.

BACKGROUND: The cortical subplate is a transitory structure involved in the formation of connections in developing cerebral cortex. Interstitial neurons, normally present in subcortical white matter (WM) of the adult brain, have escaped the programmed cell death that eliminates most subplate neurons. Previous investigations indicated a maldistribution of one population of interstitial neurons in the WM of brains of schizophrenic patients, suggesting a defect of the subplate during brain development. METHODS: Three histochemically or immunocytochemically defined neuronal populations were studied in WM beneath the middle frontal gyrus of 20 schizophrenic patients and 20 matched control subjects. RESULTS: Brains of schizophrenic patients showed significant changes in the distribution of the three neuronal populations: microtubule-associated protein 2 and nonphosphorylated neurofilament-immunoreactive neurons showed a decreased density in superficial WM and an increased density in deeper WM. Nicotinamide adenine dinucleotide phosphate-diaphorase neurons were reduced in superficial WM and showed variable densities in deeper WM. Thirty-five percent of the brains of schizophrenic patients but no brains of the control subjects showed a maldistribution of neurons toward deeper WM with at least two of the three markers. Changes in neuronal distribution were not linked to age, gender, autolysis time, or subtype of schizophrenia. CONCLUSIONS: Selective displacement of interstitial WM neurons in the frontal lobe of brains of schizophrenic patients may indicate alteration in the migration of subplate neurons or in the pattern of programmed cell death. Both could lead to defective cortical circuitry in the brains of schizophrenic patients.

Distorted distribution of nicotinamide-adenine dinucleotide phosphate-diaphorase neurons in temporal lobe of schizophrenics implies anomalous cortical development.

The distribution of neurons expressing the enzyme nicotinamide-adenine dinucleotide phosphate-diaphorase (NADPH-d) in the lateral and medial temporal lobes of schizophrenic and matched control brains was investigated in a systematic blind analysis. Schizophrenics had significantly lower numbers of NADPH-d neurons in the hippocampal formation and in the neocortex of the lateral temporal lobe but significantly greater numbers of NADPH-d neurons in the white matter of the lateral temporal lobe and a tendency toward greater numbers in parts of the parahippocampal white matter. The distorted distribution of NADPH-d neurons in the lateral temporal lobe, which may be explained by developmental disturbances, such as impaired neuronal migration or an alteration in the death cycle of transitory subcortical neurons, is similar to that found in the prefrontal cortex of schizophrenics. Alterations of cortical ontogenesis, as reflected in the distribution of NADPH-d neurons, appear to be widespread among neocortical association fields in schizophrenics and may provide a clue to the cause of the disease.

A naturalistic assessment of the motor activity of hyperactive boys. I. Comparison with normal controls.

The motor activity of hyperactive and normal boys was studied in 12 age- and classroom-matched pairs. Activity was measured continuously for a one-week period with a portable solid-state monitor. Hyperactives exhibited generally higher levels of motor activity than normal controls regardless of the time of day, including during sleep and on weekends. In a situation-by-situation analysis, hyperactives were most consistently and significantly more active than the controls during structured school activities. Little evidence was found, however, to support the hypothesis that hyperactivity is simply an artifact of the structure and attentional demands of a given setting. Pervasive increases in simple motor behavior are a clear attribute of hyperactive behavior and distinguished hyperactives from controls as well as did a standardized measure of attention.