Differential regulation of the serotonin 1 A transcriptional modulators five prime repressor element under dual repression-1 and nuclear-deformed epidermal autoregulatory factor by chronic stress.

Chronic stress is known to affect brain areas involved in learning and emotional responses. These changes, thought to be related to the development of cognitive deficits are evident in major depressive disorder and other stress-related pathophysiologies. The serotonin-related transcription factors (Freud-1/CC2D1A; five prime repressor element under dual repression/coiled-coil C2 domain 1a, and NUDR/Deaf-1; nuclear-deformed epidermal autoregulatory factor) are two important regulators of the 5-HT1A receptor. Using Western blotting and quantitative real-time polymerase chain reaction (qPCR) we examined the expression of mRNA and proteins for Freud-1, NUDR, and the 5-HT1A receptor in the prefrontal cortex (PFC) of male rats exposed to chronic restraint stress (CRS; 6 h/day for 21 days). After 21 days of CRS, significant reductions in both Freud-1 mRNA and protein were observed in the PFC (36.8% and 32%, respectively; P<0.001), while the levels of both NUDR protein and mRNA did not change significantly. Consistent with reduced Freud-1 protein, 5-HT1A receptor mRNA levels were equally upregulated in the PFC, while protein levels actually declined, suggesting post-transcriptional receptor downregulation. The data suggest that CRS produces distinct alterations in the serotonin system specifically altering Freud-1 and the 5-HT1A receptor in the PFC of the male rat while having no effect on NUDR. These results point to the importance of understanding the mechanism for the differential regulation of Freud-1 and NUDR in the PFC as a basis for understanding the related effects of chronic stress on the serotonin system (serotonin-related transcription factors) and stress-related disorders like depression.

Rapid eye movement sleep deprivation decreases long-term potentiation stability and affects some glutamatergic signaling proteins during hippocampal development.

Development of the mammalian CNS requires formation and stabilization of neuronal circuits and synaptic connections. Sensory stimulation provided by the environment orchestrates neuronal circuit formation in the waking state. Endogenous sources of activation are also implicated in these processes. Accordingly we hypothesized that sleep, especially rapid eye movement sleep (REMS), the stage characterized by high neuronal activity that is more prominent in development than adulthood, provides endogenous stimulation, which, like sensory input, helps to stabilize and refine neuronal circuits during CNS development. Young (Y: postnatal day (PN) 16) and adolescent (A: PN44) rats were rapid eye movement sleep-deprived (REMSD) by gentle cage-shaking for only 4 h on 3 consecutive days (total 12 h). The effect of REMS deprivation in Y and A rats was tested 3-7 days after the last deprivation session (Y, PN21-25; A, PN49-53) and was compared with younger (immature, I, PN9-12) untreated, age-matched, treated and normal control groups. REMS deprivation negatively affected the stability of long-term potentiation (LTP) in Y but not A animals. LTP instability in Y-REMSD animals was similar to the instability in even the more immature, untreated animals. Utilizing immunoblots, we identified changes in molecular components of glutamatergic synapses known to participate in mechanisms of synaptic refinement and plasticity. Overall, N-methyl-d-aspartate receptor subunit 2B (NR2B), N-methyl-d-aspartate receptor subunit 2A, AMPA receptor subunit 1 (GluR1), postsynaptic density protein 95 (PSD-95), and calcium/calmodulin kinase II tended to be lower in Y REMSD animals (NR2B, GluR1 and PSD-95 were significantly lower) compared with controls, an effect not present in the A animals. Taken together, these data indicate that early-life REMS deprivation reduces stability of hippocampal neuronal circuits, possibly by hindering expression of mature glutamatergic synaptic components. The findings support a role for REMS in the maturation of hippocampal neuronal circuits.

Neuroprotective effects of agmatine against cell damage caused by glucocorticoids in cultured rat hippocampal neurons.

In the present study the neuroprotective effects of agmatine against neuronal damage caused by glucocorticoids were examined in cultured rat hippocampal neurons. Spectrophotometric measurements of lactate dehydrogenase activities, beta-tubulin III immunocytochemical staining, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick-end-labeling assay (TUNEL) labeling and caspase-3 assays were carried out to detect cell damage or possible involved mechanisms. Our results show that dexamethasone and corticosterone produced a concentration-dependent increase of lactate dehydrogenase release in 12-day hippocampal cultures. Addition of 100 microM agmatine into media prevented the glucocorticoid-induced increase of lactate dehydrogenase release, an effect also shared with the specific N-methyl-D-aspartate receptor antagonist MK801 and glucocorticoid receptor antagonists mifepristone and spironolactone. Arcaine, an analog of agmatine with similar structure as agmatine, also blocked glucocorticoid-induced increase of lactate dehydrogenase release. Spermine and putrescine, the endogenous polyamine and metabolic products of agmatine without the guanidino moiety of agmatine, have no appreciable effect on glucocorticoid-induced injuries, indicating a structural relevance for this neuroprotection. Immunocytochemical staining with beta-tubulin III confirmed the substantial neuronal injuries caused by glucocorticoids and the neuroprotective effects of agmatine against these neuronal injuries. TUNEL labeling demonstrated that agmatine significantly reduced TUNEL-positive cell numbers induced by exposure of cultured neurons to dexamethasone. Moreover, exposure of hippocampal neurons to dexamethasone significantly increased caspase-3 activity, which was inhibited by co-treatment with agmatine. Taken together, these results demonstrate that agmatine can protect cultured hippocampal neurons from glucocorticoid-induced neurotoxicity, through a possible blockade of the N-methyl-D-aspartate receptor channels or a potential anti-apoptotic property.

Relationship between cortisol and serotonin metabolites and transporters in alcoholism [correction of alcolholism].

BACKGROUND: Stress hormone activation may induce clinical depression via an interference with central serotonergic neurotransmission. In alcoholics, a reduction in serotonin transporters was associated with clinical depression, and an activation of cortisol secretion is frequently found during detoxification. We assessed the interaction between stress hormone activation, serotonin transporters, monoamine metabolites in the cerebrospinal fluid (CSF), and mood states in male and female alcoholics and healthy control subjects. METHODS: The availability of serotonin transporters was measured with [I-123]beta-CIT and SPECT in the raphe area of the brainstem in 31 alcoholics after four weeks of abstinence and in 25 age-matched healthy volunteers. Concentrations of plasma cortisol were measured on the day of the SPECT scan. Within one week after the SPECT scan, we assessed monoamine metabolites and corticotropin-releasing factor (CRF) in the CSF. RESULTS: Clinical depression was associated with a reduction in serotonin transporter availability among male alcoholics. Among male alcoholics and healthy volunteers, CSF 5-HIAA and plasma cortisol concentrations were inversely correlated with the availability of raphe serotonin transporters and positively correlated with the severity of clinical depression. No significant correlations were observed between raphe serotonin transporters and HVA, MHPG and CRF concentrations in the CSF. CONCLUSION: Our findings support the hypothesis of an interaction between reduced serotonin transporters, stress hormone activation and clinical depression. They confirm the hypothesis that serotonergic neurotransmission dysfunction in alcoholism is limited to male alcoholics. The observed interactions between high cortisol concentrations and reduced serotonin transporter availability warrant further studies in major depression and other neuropsychiatric diseases with implied cortisol activation and serotonergic dysfunction.

Rapid eye movement sleep deprivation modifies expression of long-term potentiation in visual cortex of immature rats.

During rapid eye movement (REM) sleep, activity of non-retinal origin is propagated into central visual-system pathways in a manner similar, in pattern and intensity, to central visual-system activity that is exogenously generated in waking. It has been hypothesized that REM sleep, which is more abundantly represented early in life than later, functions to provide adjunct 'afferent' input for shaping synaptic connectivity during brain maturation. Here we present data that support this proposal. Recent studies have described a developmentally regulated form of in vitro long-term potentiation (LTP) in the visual cortex that is experience- and age-dependent. In immature rats, suppression of retinal activation of the visual system by removal of visual experience (dark rearing) extends the age when the developmentally regulated form of LTP can be produced. This study tests whether suppression of REM-state activation of the visual system also lengthens the developmental period in which this specific form of LTP can be elicited. Young rats were deprived of REM sleep by the multiple-small-platforms-over-water method during the typically latest week for induction of such LTP in slices of visual cortex. After this week, we could still induce LTP in slices from nearly all the REM-sleep-deprived rats (8/9) but not from age-matched rats that had not lost REM sleep (0/5). The control rats had been housed on large platforms that allow the animals to obtain REM sleep. Only body weights and the concentration of thyrotrophin-releasing hormone in the hypothalamus distinguished home-caged, normal-sleeping controls from both groups of platform animals. On all measures, stress levels were not dissimilar in the two platforms groups. After 7 days of behavioral suppression of REM sleep in immature rats, and consequent reduction of the intense, extra-retinal activity endogenously generated during this sleep state, we found that the period was extended in which developmentally regulated synaptic plasticity (LTP) could be elicited in slices of visual neocortex. These studies support the role of REM sleep and its associated neuronal activity in brain maturation.

CSF thyrotropin-releasing hormone concentrations differ in patients with schizoaffective disorder from patients with schizophrenia or mood disorders.

OBJECTIVE: To determine if there were differences in CSF-TRH concentrations among several acute major psychiatric disorders and to investigate the effects of antipsychotic treatment on CSF-TRH levels. METHOD: CSF-TRH concentrations were measured in 62 psychiatric inpatients during an acute phase of illness after a drug-free period. CSF-TRH measurements were repeated in 14 of these patients after 4 weeks of antipsychotic treatment. RESULTS: Post-hoc tests (Tukey HSD) revealed significant differences among patients with schizoaffective disorder and both schizophrenia (P<0.03) and major depression (P<0.01). There were no significant differences between pre and posttreatment levels of CSF-TRH in the 14 patients treated with conventional agents for 4 weeks (1.54 pg/ml vs. 1.47 pg/ml). However, patients with a reduction in CSF-TRH concentration had a significantly better symptom response measured by the Brief Psychiatric Rating Scale (BPRS) positive factor (61% in six subjects) vs. those who had an increase in posttreatment CSF-TRH (29% in eight subjects; t=2.2; d.f.=12; P<0.04). CONCLUSIONS: These results provide further evidence for a neuromodulatory role for TRH and suggest a re-examination of its behavioral effects and interactions with brain neurotransmitter systems relevant to major psychotic and mood disorders.

Effects of sertraline on regional neuropeptide concentrations in olfactory bulbectomized rats.

Corticotropin-releasing factor (CRF) and thyrotropin-releasing hormone (TRH) are two neuropeptides that exhibit increased cerebrospinal fluid (CSF) concentrations during major depressive episodes while somatostatin (somatotropin-release inhibiting factor, SRIF) is decreased. Clinical and basic research findings indicate that clinically effective antidepressant therapies often normalize the indicators of CRF and TRH hypersecretion as well as SRIF hyposecretion. The olfactory bulbectomized (OBX) rat is used to screen potential antidepressant drugs for clinical efficacy. This model requires chronic administration of the antidepressant drug to normalize OBX-induced behaviors such as increased locomotion in a novel environment. This report describes the regional brain concentration changes in CRF, TRH and SRIF produced by OBX and demonstrates the ability of the selective serotonin re-uptake inhibitor and antidepressant drug, sertraline (10 mg/kg), to normalize certain of these alterations in regional neuropeptide concentrations as well as normalizing OBX-induced increases in locomotor activity. OBX-induced increases in CRF concentrations in the hypothalamus and bed nucleus of the stria terminalis were specifically and significantly decreased by sertraline. OBX-induced increases in TRH concentrations in the hypothalamus were reversed by sertraline. The concentration of SRIF was significantly reduced by OBX in the anterior caudate and the piriform cortex, but sertraline reversed these changes only in the anterior caudate.

Modeling geriatric depression in animals: biochemical and behavioral effects of olfactory bulbectomy in young versus aged rats.

Geriatric depression exhibits biological and therapeutic differences relative to early-onset depression. We studied olfactory bulbectomy (OBX), a paradigm that shares major features of human depression, in young versus aged rats to determine mechanisms underlying these differences. Young OBX rats showed locomotor hyperactivity and a loss of passive avoidance and tactile startle. In contrast, aged OBX animals maintained avoidance and startle responses but showed greater locomotor stimulation; the aged group also exhibited decreased grooming and suppressed feeding with novel presentation of chocolate milk, effects which were not seen in young OBX. These behavioral contrasts were accompanied by greater atrophy of the frontal/parietal cortex and midbrain in aged OBX. Serotonin transporter sites were increased in the cortex and hippocampus of young OBX rats, but were decreased in the aged OBX group. Cell signaling cascades also showed age-dependent effects, with increased adenylyl cyclase responses to monoaminergic stimulation in young OBX but no change or a decrease in aged OBX. These data indicate that there are biological distinctions in effects of OBX in young and aged animals, which, if present in geriatric depression, provide a mechanistic basis for differences in biological markers and drug responses. OBX may provide a useful animal model with which to test therapeutic interventions for geriatric depression.

Cerebrospinal fluid concentrations of corticotropin-releasing hormone, vasopressin, and somatostatin in depressed patients and healthy controls: response to amitriptyline treatment.

The effect of amitriptyline upon hypothalamic-pituitary-adrenal [HPA]-system-regulating neuropeptides (corticotropin-releasing hormone [CRH], vasopressin, somatostatin) was studied in a group of depressed elderly patients and controls. A first lumbar puncture was performed in 37 depressed in-patients. This was followed by a 6-week medication phase with amitriptyline. Upon its completion a second cerebrospinal fluid (CSF) sample was obtained in 18 of these 37 patients. In 25 healthy controls a first lumbar puncture was done eleven of these individuals agreed to take 75 mg/d amitriptyline for 6 weeks and to participate in the follow-up CSF study. Within the group of depressed patients amitriptyline led to a significant decrease of CSF CRH in treatment responders only (F1, 16 = 5.2; P < 0.02). Also, in normal controls CSF CRH concentration tended to decrease with amitriptyline treatment (t-test; P < 0.09). No effects of amitriptyline upon vasopressin or somatostatin were observed. In normal controls (r = 0.4; P < 0.02) and in patients (r = 0.4; P < 0.03) age correlated positively with baseline CSF somatostatin. A trend for CSF CRH to increase with aging was found only in controls (r = 0.3; P < 0.09); patients did not show a significant association here. Finally, CSF neuropeptide concentration at baseline did not differ between the group of depressed patients and healthy controls. Our study corroborates the evolving concept that antidepressants effect various components of the HPA system with the net result of a reduction in its activity. In addition, we found CSF CRH and CSF somatostatin concentrations to be better reflections of age than of depression and, finally, that during aging and during depression the HPA system changes in similar directions.

CSF neurotensin concentrations and antipsychotic treatment in schizophrenia and schizoaffective disorder.

OBJECTIVE: The relationship between CSF neurotensin concentrations and measures of psychopathology in patients with schizophrenia or schizoaffective disorder was examined before and after treatment with antipsychotic drugs. METHOD: CSF neurotensin concentrations were measured in 42 drug-free patients with schizophrenia or schizoaffective disorder. For 18 of these patients, CSF neurotensin was measure again after 4 weeks of antipsychotic treatment. RESULTS: Significantly higher levels of pretreatment psychopathology were observed in the patients with the lowest CSF neurotensin concentrations. Furthermore, improvements in overall psychopathology and, particularly, negative symptoms were correlated with increases in CSF neurotensin concentrations during treatment. CONCLUSIONS: These findings provide further evidence for a role of neurotensin the pathophysiology of psychosis and in the mechanism of action of antipsychotic drugs.

Cerebrospinal fluid concentrations of corticotropin-releasing hormone (CRH) and diazepam-binding inhibitor (DBI) during alcohol withdrawal and abstinence.

The neuropeptides diazepam binding inhibitor (DBI) and corticotropin-releasing hormone (CRH) elicit anxietylike symptoms when administered intracerebroventricularly to laboratory animals. Because of the similarities between the symptoms of certain anxiety states and the alcohol withdrawal syndrome, we hypothesized that increased secretion of either of these endogenous neuropeptides may, at least in part, be responsible for the symptoms of alcohol withdrawal. We therefore measured DBI and CRH concentrations in cerebrospinal fluid (CSF) of 15 alcohol-dependent patients during acute withdrawal (Day 1) and again at 3 week's abstinence (Day 21). In addition, plasma concentrations of cortisol were measured to evaluate the relationship between pituitary-adrenal axis activation and CSF CRH concentrations. CSF CRH (p < .04), but not CSF DBI, was significantly higher on Day 1 than on Day 21. Although there was a significant decrease in plasma cortisol from Day 1 to Day 21 (p < .001), a significant correlation between CSF CRH and plasma cortisol concentrations was not observed at either time point. Neither CSF neuropeptide correlated with clinical measures of withdrawal severity. These tentative findings may implicate CRH, but not DBI, in the pathogenesis of alcohol withdrawal. Alternately, the central release of CRH and DBI may not be adequately reflected in lumbar CSF.

Elevated cerebrospinal fluid corticotropin-releasing factor in Tourette's syndrome: comparison to obsessive compulsive disorder and normal controls.

Stress- and anxiety-related fluctuations in tic severity are cardinal features of Tourette's syndrome (TS), and there is evidence for involvement of noradrenergic mechanisms in the pathophysiology and treatment of the disorder. To examine further the pathobiology of this enhanced vulnerability to stress and anxiety, we measured central activity of corticotropin-releasing factor (CRF) in patients with TS and the related condition, obsessive compulsive disorder (OCD). Lumbar cerebrospinal fluid (CSF) was obtained in a standardized fashion for measurement of CRF from 21 medication-free outpatients with TS, 20 with OCD, and 29 healthy controls. The TS patients had significantly higher levels of CSF CRF than both the normal controls and the OCD patients. However, there was no difference in CSF CRF between the OCD patients and the normal controls. Group differences in CSF CRF were unrelated to current clinical ratings of depression, anxiety, tics, and obsessive compulsive behaviors. Although the functional significance of this finding remains to be elucidated, these results are consistent with the hypothesis that stress-related neurobiological mechanisms may play a role in the pathobiology of TS.

Cerebrospinal fluid corticotropin-releasing factor concentrations in patients with anxiety disorders and normal comparison subjects.

Cerebrospinal fluid (CSF) concentrations of corticotropin-releasing factor (CRF) were measured in a group of patients with anxiety disorders and normal comparison subjects (NC) to explore the hypothesis that abnormalities in CRF neuronal regulation occur in patients with anxiety disorders. Analysis of variance (ANOVA) revealed no differences in CSF CRF concentrations between the four diagnostic categories: panic disorder (PD), generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), and NCs. Male OCD patients had higher CSF CRF concentrations than men with PD and GAD and male NCs. CSF CRF concentration was positively correlated with age in women but not in men. These findings suggest that central neuronal CRF regulation may be affected by both age and gender.

High affinity choline transporter status in Alzheimer's disease tissue from rapid autopsy.

The degeneration of nucleus basalis cholinergic neurons in Alzheimers disease (AD) has led to therapies that attempt to increase the synaptic availability of acetylcholine in the remaining cholinergic nerve terminals and to thereby reverse or slow the progressive dementia accompanying the disease process. The inadequacy of current choline-replacement therapies suggests that utilization of choline may be disordered and the rate-limiting step in acetylcholine synthesis, the high affinity choline transporter, may be involved. An adequate test of this hypothesis requires the use of fresh, unfrozen tissue, as the transporter activity declines rapidly after death. Using tissue acquired within two hours of death, the activity of the high affinity choline transporter was shown to be increased in cortical brain regions from AD patients compared to non-AD controls. Further studies using frozen tissues with similar short postmortem acquisition times, revealed the expression of the high affinity uptake transporter to be increased in AD cortex as well. When the ratio of regional uptake activity or expression to the regional level of choline acetyltransferase was calculated, the increase in choline transporter activity and expression was clearly statistically significant. Further statistical significance in the choline transporter activity of the AD group was achieved when the putamen, a region without marked pathology in AD, was used as an internal standard to control for agonal state differences in the individual patients contributing tissue to this study. These increases in choline transporter expression and activity in AD indicate disordered regulation of this rate-limiting component of acetylcholine synthesis above and beyond that required to compensate for the reduced cholinergic synaptic availability in AD.

Elevation of CSF somatostatin concentrations in mania.

OBJECTIVE: The aim of this study was to compare levels of CSF somatostatin (somatotropin release-inhibiting factor) in drug-free patients with different major psychiatric disorders. METHOD: CSF somatostatin concentrations were measured in 66 drug-free inpatients with Research Diagnostic Criteria diagnoses of schizophrenia, major depressive disorder, manic disorder, or schizoaffective disorder. RESULTS: In comparison with both the patients with schizophrenia and the patients with schizoaffective disorder, the manic patients had markedly elevated CSF somatostatin concentrations. The depressed patients had significantly higher levels than the schizophrenic patients. CONCLUSIONS: Mania is associated with relatively higher CSF somatostatin concentrations.

Apparent seasonal rhythms in hypothalamic neuropeptides in rats without photoperiod changes.

An apparent seasonal or circannual rhythm in the hypothalamic content of CRF, TRH, neurotensin, and neuromedin N has been observed in 12 separate monthly coherts (n = 10@ or 130 total) adult, male Sprague-Dawley rats obtained at the same time each month from a single commercial supplier and held under constant (12:12) photoperiod conditions since birth. Both annual and 4-month (terannual) harmonics can be statistically discerned in these apparent rhythms, which exhibit cycles containing concentration changes up to 3-fold the lowest levels across the year (CRF increases 390%, TRH increases 173%, neurotensin increases 136%, and neuromedin N increases 150%). Hypothalamic somatostatin did not exhibit these statistically significant robust rhythms nor did any peptide in regions outside the hypothalamus. These data indicate that a mechanism allowing enhanced or diminished physiological availability of these regulatory neuropeptides at different times of the year may exist and may display distinct cycles even in the absence of normal photoperiod cues. Possible regulatory responses of pituitary receptor populations for these hypothalamic peptides must be considered. As certain of these neuropeptides also appear to be altered in the cerebrospinal fluid of patients with major depression or schizophrenia, similar hypothalamic cyclic changes may underly psychiatric symptoms with seasonal periodicity.

Neurochemical correlates of sympathetic activation during severe alcohol withdrawal.

Cerebrospinal fluid (CSF) was obtained from 17 patients during acute alcohol withdrawal. Eight of these 17 patients had a second lumbar puncture a mean of 11.9 +/- 8.1 (SD) days later, when the clinical signs of alcohol withdrawal had subsided. CSF 3-methoxy-4-hydroxyphenylglycol concentrations declined significantly (p < 0.05) during the course of alcohol withdrawal from 52.0 +/- 22.1 (SD) to 39.6 +/- 12.6 pM/ml. In early withdrawal, there was a significant positive correlation between CSF norepinephrine (NE) and corticotropin releasing hormone (CRH) concentrations (r = 0.95, p < 0.001). Both NE and CRH concentrations correlated positively with diastolic blood pressure (r = 0.88, p < 0.001 and r = 0.62, p < 0.05, respectively). In all samples, CSF 5-hydroxyindole acetic acid concentrations correlated positively with CSF-homovanillic acid concentrations (r = 0.83, p < 0.001). These findings indicate significant perturbations of the noradrenergic neuronal system and a change in CRH-NE interactions during acute alcohol withdrawal.

Cerebrospinal fluid somatostatin concentrations in schizophrenia and schizoaffective disorder: the effects of antipsychotic treatment.

The authors examined the effects of antipsychotic treatment on cerebrospinal fluid somatostatin like immunoreactivity (CSF SLI) in 14 schizophrenic and 3 schizoaffective patients. There was a modest but significant increase in CSF SLI in 13 out of the 14 schizophrenic patients. In addition, there was a significant positive correlation between duration of treatment and post-treatment CSF SLI concentrations. No differential response was noted in patients also treated with the anticholinergic benztropine.