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Major depression is characterized by diverse debilitating symptoms that include hopelessness and anhedonia (1). Dopamine neurons involved in reward and motivation (2-9) are among many neural populations that have been [...]

Ventral tegmental area (VTA) dopamine neurons in the brain's reward circuit have a crucial role in mediating stress responses (1-4), including determining susceptibility versus resilience to social-stress-induced behavioural abnormalities (5). [...]

Introduction Investigating the brain changes that accompany depression and recovery from depression is complicated by the fact that treatments typically take days or weeks to have substantial effects on mood. [...], Background: Partial or total overnight sleep deprivation produces immediate mood improvement in about 50% of patients with depression, but not in healthy controls. Our objectives were to compare the neurochemical changes that accompanied partial overnight sleep deprivation in healthy and depressed participants, and to compare baseline neurochemical profiles and overnight neurochemical changes between those depressed participants who did and did not respond to sleep loss with mood improvement. Methods: We studied 2 brain regions (left dorsal prefrontal area and pons) in 12 women with unipolar depression and in 15 healthy women using proton magnetic resonance spectroscopy acquired at 1.5 T. The scans took place at baseline and 24 hours later after a night with sleep restricted to a maximum of 2.5 hours (22:30-01:00). We assessed 3 neurochemical signals (referenced to internal water): N-acetylaspartate (NAA), choline compounds (Cho) and creatine-plus-phosphocreatine (tCr). Results: In both groups combined, sleep restriction caused a 20.1% decrease in pontine tCr ([F.sub.1-16] = 5.07, p= 0.039, Cohen's d= 0.54) and an 11.3% increase in prefrontal Cho ([F.sub.1-21] = 5.24, p= 0.033, Cohen's d= 0.46). Follow-up tests revealed that prefrontal Cho increases were significant only among depressed participants (17.9% increase, [t.sub.9] = -3.35, p = 0.008, Cohen's d = 1.06). Five depressed patients showed at least 30% improvement in mood, whereas 6 showed no change or worsening in mood after sleep restriction. Baseline pontine Cho levels distinguished subsequent responders from nonresponders to sleep restriction among depressed participants (z = 2.61, p= 0.008). Limitations: A limitation of this study is the relatively small sample size. Conclusion: Sleep restriction altered levels of pontine tCr and prefrontal Cho in both groups combined, suggesting effects on phospholipid and creatine metabolism. Baseline levels of pontine Cho were linked to subsequent mood responses to sleep loss, suggesting a role for pontine phospholipid metabolism in mood effects of sleep restriction.

Key Words depression, immune function, social support, interleukin 6 * Abstract Negative emotions can intensify a variety of health threats. We provide a broad framework relating negative emotions to a [...]

Objective: It has been hypothesized that adequate concentrations of vitamin B12 and folate are essential to maintain the integrity of the neurological systems involved in mood regulation, but epidemiologic evidence [...]

Two mechanistically distinct forms of long-term depression (LTD) coexist at synapses in the CA1 region of hippocampus (1). Induction of one form depends on activation of N-methyl-D-aspartate receptors (NMDARs) (2, [...], A hippocampal pyramidal neuron receives more than [10.sup.4] excitatory glutamatergic synapses. Many of these synapses contain the molecular machinery for messenger RNA translation, suggesting that the protein complement (and thus function) of each synapse can be regulated on the basis of activity. Here, local postsynaptic protein synthesis, triggered by synaptic activation of metabotropic glutamate receptors, was found to modify synaptic transmission within minutes.

Antidepressant and Circadian Phase--Shifting Effects of Light WE SHOWED EARLIER (1) THATbright (2500 lux) light is necessary for suppression of nighttime melatonin production in humans, whereas other animals respond to [...]

The Immune System 'Belongs in the Body' Over the years, a great many reports, some anecdotal but others more rigorous, have suggested that psychological factors such as stress might influence [...]

Elevated Concentrations of CSF Corticotropin-Releasing Factor-Like Immunoreactivity in Depressed Patients A large proportion of patients with major depression (DSM III) or endogenous depression (Research Diagnostic Criteria) exhibit hyperactivity of the [...]

Steroids May Influence Changes in Mood A person with too much of the hormone cortisol in the bloodstream may be depressed, and have Cushing's disease, anorexia nervosa, or clinical depression. [...]

Nature, Nurture, and Behavior The recent reports of the chromosomal localization of genes related to Alzheimer's disease and manic depression are major discoveries that bring promise of help to those [...]