Stress and Depression


Our body can handle most common stressors by adapting. However, chronic stress can wear down our body and cause us to become ill, both physically and mentally. If you are not able to cope with chronic stress well, stressful life situations can increase the risk of serious health problems, including psychiatric disorders such as anxiety and panic disorders and depression. Despite the prevalence of stress and the severity of its effects, surprisingly little is known about how this risk factor influences depression.

Dr. Jeremy Amiel Rosenkranz is using his 2009 BRF Seed Grant to understand how stress impacts depression. If one can reduce the impact of stress, one can reduce the incidence of depression and other psychiatric disorders. There are many effective antidepressants, but waiting until someone already has depression is not a preventative strategy.

To determine a novel therapeutic target to reverse stress-induced impairments, Dr. Rosenkranz must first determine how stress modifies emotion. Stress activates “emotion circuits” in the brain; and repeated stress sensitizes these circuits. The amygdala, which is located deep within the medial temporal lobes of the brain, is involved in the processing and memory of emotional reactions. Because of its key role in emotion, the amygdala is a possible target of the effects of stress on emotion. Under normal stress, the amygdala is activated and an appropriate behavioral response is elicited. But under chronic stress the amygdala becomes hyperactivated which leads to an abnormal response or emotional disturbance.

While there is growing evidence for enduring effects of chronic stress on morphological, physiological and biochemical features of neurons in several brain regions, little is known about the effects of chronic stress on amygdala neuronal electrophysiology – the electrical activity of neurons. Because neurons share similar characteristics across mammalian species, Dr. Rosenkranz will use rodents to study the effects of stress on the amygdala. The rodents will be exposed to stressors and then electrophysiology recording will be performed which measures the activity of neurons. Dr. Rosenkranz will test if chronic stress increases excitability of amygdala neurons via a specific ion channel (KCa channel) that regulates neuronal activity. These channels are a likely candidate because they are modified by the steroid corticosterone which is a major stress hormone in rodents. If it is shown that KCa channel activity is altered during chronic stress, then this channel is a new potential pharmacological target to prevent and treat the effects of stress on disorders of emotion, such as depression.

Using the data collected from his 2009 Seed Grant, Dr. Jeremy Amiel Rosenkranz was able to turn this $40,000 grant into over $1.5 million in additional funding from the National Institutes of Health.

Other Grants

Lindsay M. De Biase, Ph.D., University of California Los Angeles
The Role of Microglial Lysosomes in Selective Neuronal Vulnerability
Synapses, the sites of signaling between neurons in the brain, play essential roles in learning, memory, and the health of neurons themselves. An enduring mystery is why some neurons are…
How the Nervous System Constructs Internal Models of the External World
As animals navigate their environments, they construct internal models of the external sensory world and use these models to guide their behavior. This ability to incorporate ongoing sensory stimuli into…
Xiaojing Gao, Ph.D., Stanford University
When Neural Circuits Meet Molecular Circuits: Quantitative Genetic Manipulation with Single-cell Consistency
Cells are the building blocks of our bodies. We get sick when the cells “misbehave”. The way modern gene therapies work is to introduce genes, fragments of DNA molecules that…
Rafiq Huda, Ph.D., Rutgers University
Conducting the Orchestra of Movement—Functional Role of Striatal Astrocytes in Health and Disease
Movement requires coordinated activity across a large brain-wide network. The striatum is a particularly important part of this circuit; it integrates motor-related information from many distinct brain regions to regulate…