Lumateperone Normalizes Pathological Levels of Acute Inflammation and Stimulates Important Pathways Involved in Mood Regulation

Highlights from Posters Presented at the Society of Biological Psychiatry Meeting, April 27-29, 2023 in San Diego

Sophie Dutheil of Intra-Cellular Therapies, Inc. reported that “In male and female C57BL/6 mice subjected to an acute stress or immune challenge, lumateperone reduced elevated levels of key proinflammatory cytokines. A number of key genes and pathways associated with the maintenance of tissue integrity and blood-brain barrier function were also altered by a single dose of lumateperone. Furthermore, we found that lumateperone administration conferred anxiolytic- and antianhedonic-like properties while enhancing the mTORC1 signaling pathway in the PFC.”

Study in Mice Suggests that Compound in Turmeric May Reduce Anxiety and Promote Resilience to Stress

June 12, 2019 · Posted in Potential Treatments · Comment 

turmericChronic stress is a risk factor for the development of mood and anxiety disorders. Researchers have begun to focus on how to promote resilience to stress. Curcumin is a micronutrient found in turmeric that has anti-inflammatory and antidepressant effects and may promote such resilience.

Researchers studying human depression often design studies to see how mice with chronic social defeat stress respond to various interventions. Mice who are repeatedly menaced by a larger mouse begin to show symptoms that resemble human depression, such as social avoidance, lack of interest in saccharin compared to plain water (a stand-in for loss of enjoyment or anhedonia in humans), and anxiety.

In a 2018 article in the journal Neuropsychopharmacology, researcher Antonio V. Aubry and colleagues described the effects of curcumin on mice undergoing chronic social defeat stress. Mice who were given a diet that consisted of 1.5% curcumin showed a 4.5-fold increase in resilience to social defeat stress, measured by their performance during a test of social interaction. Among the 129 mice in the study, 64% showed the increase in resilience, the remaining 36% did not respond to the curcumin diet and had the normal ‘depressed’ response. The mice who responded well to curcumin released less of the stress hormone corticosterone, and they also had lower levels of the inflammatory marker IL-6.

All of the mice on the curcumin diet showed reduced anxiety during tests that forced them to travel through open spaces (when they prefer to stay in more enclosed spaces or move along the edges of an enclosure).

Chronic Fatigue Linked to Low Metabolism

September 27, 2017 · Posted in Theory · Comment 

fatigue

A 2016 article in the journal PNAS suggests that people with chronic fatigue syndrome, also known as myalgic encephalopathy, share a low metabolic profile.

In the study, researcher Robert K. Naviaux and colleagues measured 612 different metabolites in 63 metabolic pathways. They found abnormalities in 20 of these pathways in people with chronic fatigue. Eighty percent of the abnormal measurements were low.

The low metabolic profile resembled a stage of development some worm larvae go through when environmental conditions are harsh. The phase, called dauer, can be brought on by harsh temperatures, low food supply, or pheromones that indicate high population density. It resembles hibernation in some ways, including changes to mitochondrial function. Dauer allows larvae to live for 4 months rather than their normal lifespan of 3 weeks. They can resume normal development when conditions improve.

The authors suggest that chronic fatigue is a metabolic response to environmental stress, and hope to clarify the link between mitochondrial function and the illness.

Immune Response to Repeated Stress Alters Behavior in Mice

April 12, 2017 · Posted in Course of Illness · Comment 

Laboratory black mouse in the hands of the experimenter

In research presented at the 2016 meeting of the Society of Biological Psychiatry, Jonathan P. Godbout described how an immune reaction to repeated stressors may lead to anxious behaviors in mice.

Mice were repeatedly defeated by a larger animal, a form of stress that produces a depression-like state. This provoked an immune response in the mice—the release of a type of white blood cells called monocytes from the bone marrow into the circulatory system. These inflammatory monocytes then traveled to the brain and spleen, attracted by signaling proteins called chemokines. The monocytes in turn produced inflammatory marker interleukin-1beta.

The defeat stress also provoked a reaction in the central nervous system, where microglia were activated.

These changes produced inflammation and anxiety-like behaviors in the mice. Blocking the microglial activation, monocyte recruitment to the brain, or interleukin-1beta signaling each reversed the anxiety-like behaviors.

Another researcher, Scott Russo, has shown that leukocytes, another type of white blood cells, secrete inflammatory interleukin-6 following defeat stress, and blocking this secretion prevents defeat stress–related behaviors.

How Stress Triggers Inflammation and Depression

April 4, 2017 · Posted in Course of Illness, Neurobiology · Comment 

woman squeezing stress ballDepression and bipolar disorder are associated with increases in markers of inflammation that can be found in the brain and blood. It is increasingly clear that the mechanisms that cause depression are not just in the brain, but actually throughout the body. These include two signaling systems that begin in the bone marrow and the spleen.

When a small mouse is repeated defeated by a larger animal, they show depression-like symptoms known as defeat stress. Animal studies have shown that stress and danger signals are perceived and relayed to the amygdala and the hypothalamus. The sympathetic nervous system releases the neurotransmitter norepinephrine into bone marrow, where stem cells are turned into activated monocytes (a type of white blood cells) that are then released into the blood. The monocytes travel to the brain, leading to the activation of more inflammatory cells.

Blocking part of this process can prevent the depression-like behaviors from occurring. If the bone marrow monocytes are blocked from entering the brain, inflammation and defeat stress behaviors like social avoidance do not occur. However, if there is a second bout of defeat stress, primed monocytes that have been stored in the spleen are released and travel to the brain, producing further increases in inflammatory cells and even more defeat stress behaviors.

If these monocytes from the spleen are blocked, the inflammation and the reaction to the new stressor do not occur.

Stress also activates lymphocytes (another type of white blood cells) to secrete the inflammatory cells Il-6. If this Il-6 secretion is inhibited, defeat stress behaviors can be prevented.

Defeat stress also leads to the release of the neurotransmitter glutamate. Some of this cascade begins in the brain, which evaluates stressors and releases IL-1 beta, another type of inflammatory cell. It slows down the production of glutamate, while IL-6 can endanger neurons and is associated with anhedonia—loss of interest in pleasurable activities. This cascade also leads to the production of another type of inflammatory cell, TNF-alpha, which has adverse effects on biochemistry, brain, and behavior.
This understanding of the role of the brain and body provides new targets for drug development. If inflammatory processes are blocked, defeat stress behaviors do not occur. Researcher Michael D. Weber and colleagues described this process in detail in the journal Neuropsychopharmacology Reviews in 2017.

Together these observations suggest that inflammatory processes in the body are crucial to the development of some stress- and inflammation-related depressive behaviors.

Early Life Stress Affects Volume of the Hippocampus

December 12, 2016 · Posted in Risk Factors · Comment 

early life stressors affect hippocampal volume

New research shows that there are crucial periods of early life in which a stressful event can reduce hippocampal volume in adolescence. In a study presented at the 2016 meeting of the Society of Biological Psychiatry, Kathryn L. Humphreys and colleagues found that children who experienced a significant stressor before age 8 had smaller hippocampi in early adolescence than children who did not have a significant stressor early in life.

The severity of the stressors that occurred when children were between the ages of 0 and 2 predicted the volume of the hippocampus later in life. This was true to a lesser extent for stressful events that occurred between the ages of 3 and 5. No effect was seen for stressful events that took place between the ages of 6 and 8.

The period of sensitivity to stressful events between ages 0 and 2 and its effects on hippocampal volume could influence a variety of psychiatric outcomes in conditions such as depression and post-traumatic stress disorder (PTSD).

Amygdala Hyperactivity Linked to Family History of Depression

December 9, 2016 · Posted in Risk Factors · Comment 

family history of depression

In new research presented at the 2016 meeting of the Society of Biological Psychiatry, researcher Tracy Barbour and colleagues revealed that youth with a family history of depression showed more amygdala activation in response to a threat than people without a family history of depression. This amygdala hyperactivity was linked to low resilience to stress and predicted worsening depressive symptoms over the following year.

In the study, 72 non-depressed youth were shown images of cars or human faces or cars that seemed to loom in a threatening way. Brain scans showed increased amygdala activity in participants with a family history of depression compared to those without such a history.

The amygdala is an almond-shaped part of the brain in the temporal lobe that has been linked to emotional reactions and memory, decision-making, and anxiety.

IL-6 in Blood and Bone Marrow Linked to Lack of Resilience to Stress

December 8, 2016 · Posted in Risk Factors · Comment 

stress and inflammation

Rodents who are repeatedly defeated by larger animals often exhibit depression-like behaviors. In new research that researcher Georgia E. Hodes presented at the 2016 meeting of the Society of Biological Psychiatry, animals who are susceptible to these social defeat stress behaviors showed immune irregularities, including high levels of the inflammatory marker interleukin-6.

An intervention to prevent the mice from secreting interleukin-6 in blood and bone marrow took away their susceptibility to social defeat stress. When bone marrow from rodents with no interleukin-6 was transplanted into susceptible mice, the recipients showed resilience to social defeat stress. Conversely, a transplant from susceptible mice to those mice without IL-6 led to social defeat stress in the previously “immune” mice.

This research shows that the peripheral immune system, including blood and bone marrow, plays an important role in depression-like behaviors in mice.

Crack Cocaine Use and Early Life Stressors Shorten Telomeres

August 8, 2016 · Posted in Risk Factors · Comment 

crack cocaine can shorten telomeres

Telomeres are repeated DNA sequences that sit at the end of chromosomes and protect them during cell replication. Shorter telomeres are associated with aging and an increase in multiple medical and psychiatric disorders, while some healthy behaviors including exercising, eating healthy, meditating, and avoiding smoking can help maintain telomere length. Lithium treatment also increases telomere length.

Recent research by Mateus Levandowski and colleagues found that people who were dependent on crack cocaine had shorter telomeres than elderly women without psychiatric illnesses, particularly if the crack cocaine users had also experienced stress early in life, such as maltreatment or neglect.

Since short telomeres are associated with a variety of medical and psychiatric problems and premature aging, the combined effects of drug use and early life stressors are likely to have an adverse impact on people who have experienced both.

Mice Who Witness Another Being Attacked Show Depression-Like Behaviors

June 27, 2016 · Posted in Risk Factors · Comment 

mouse witnessing traumatic eventsStress is a risk factor for depression and other mental health disorders. Researchers are currently working to clarify how stress leads to depression, anxiety, and post-traumatic stress disorder, and why trauma early in life has lasting consequences.

Two recent studies in mice examined whether just witnessing a stressful event leads to depression-like behaviors. In one, adult female mice watched a male mouse as it was repeatedly attacked by a larger mouse. After ten days of this, the female mice were socially withdrawn, had lost interest in drinking sucrose, and gave up more easily during a physical challenge. They also lost weight and showed higher levels of the stress hormone corticosterone in their blood. The researchers, led by Sergio Iniguez, believe their study clarifies how witnessing traumatic events can lead to stress-induced mood disorders.

In the other study, by Carlos Bolanos-Guzman, adolescent male mice witnessed another mouse being attacked. Both the mice that went through the physical stress of being attacked and the mice that went through the emotional stress of watching the attacks occur showed similar depressive behaviors to the mice in the previous study—social withdrawal, loss of interest in sucrose, decreased food intake and exploration of the environment, and decreased motivation in physical challenges. These behaviors persisted into adulthood. Both groups of mice also had increased levels of corticosterone and reduced expression of a particular protein in the ventral tegmental area, a part of the brain linked to stress response. Bolanos-Guzman suggests that both physical and emotional stress have lifelong consequences in mice.

The studies were presented at a scientific meeting in December.

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