Suppressed dopaminergic activity in a specific brain area may play a causal role in depression.
Major depressive disorder (MDD) is a heterogenous mental illness characterized by deficits in mood and reward processing. The ventral tegmental area (VTA) of the brain plays a critical role in regulating reward processing via its projection to the nucleus accumbens (NAc), and altered cellular function in VTA has been implicated in mediating depression. In a recent study, Zhong et al. begin to elucidate the cellular and molecular mechanisms underlying the dysregulation of VTA in depression. Using the widely validated chronic mild stress (CMS) mouse model, the authors verified that the depression-like behavior observed in this model is linked to decreased neuronal firing in the VTA.
The hyperpolarization-activated cation current (Ih), mediated by hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) channels, increases VTA firing. First, the authors tested whether Ih was suppressed in mice subjected to CMS by analyzing ex vivo brain slices. They discovered that in CMS-exposed mice, this current was suppressed in NAc-projecting VTA dopamine neurons, a pathway central to reward processing. The authors then demonstrated that pharmacological blockade of Ih suppressed VTA firing to a lesser extent in mice exposed to CMS than in nonstressed controls, providing additional evidence that decreased Ih contributed to the decreased VTA dopamine neuron firing observed in the CMS model.
Next, to determine whether suppression of Ih was sufficient to induce depression-like behavior, the authors applied a virally mediated RNA interference strategy. Knocking down HCN2 suppressed Ih and induced depression-like behavior in nonstressed mice. Conversely, virally mediated overexpression of HCN2 increased Ih and rendered animals resistant to the depression-inducing effects of CMS.
Together, these findings demonstrate that CMS-induced depression-like behavior is at least partially mediated by decreased Ih in VTA dopaminergic neurons. Interestingly, earlier findings in mice exposed to chronic social defeat stress, another widely validated mouse model of depression, found that depression-like behavior was mediated by an increase in Ih. Thus, although both models suggest that dysregulation of VTA dopamine activity is central, further experiments will be necessary to determine the broader neural mechanisms whereby increases or decreases in VTA dopaminergic activity can converge to yield a common set of depression-related behavioral deficits.
Dopamine rich foods
- Dairy foods such as milk, cheese and yogurt.
- Unprocessed meats such as beef, chicken and turkey.
- Omega-3 rich fish such as salmon and mackerel.
- Fruit and vegetables, in particular bananas.
- Nuts such as almonds and walnuts.
- Dark chocolate.
Ways to increase dopamine
lack of motivation; fatigue; apathy; procrastination; inability to feel pleasure; low libido; inability to connect with others; sleep problems; mood swings; hopelessness; memory loss; inability to …. Sunlight can increase the number of dopamine receptors and create vitamin D which activates the genes that release dopamine.
Treating a dopamine deficiency can help you take back your health! How? First, you need to understand that depression is a disease that can be caused by a dopamine deficiency. In many cases, it is caused by actual physiologic changes in your brain. Therefore, when you feel depressed, don’t think of it as a defect in your …
Aug 14, 2017 – When you struggle to get a good night’s sleep, it can affect your brain. As little as one night of lost sleep may affect your levels of dopamine in your brain. … According to Thomas Roth, Ph.D., in the “Journal of Clinical Sleep Medicine,” a disorder is a condition associated with negative consequences, and …
Jan 24, 2012 – By Maylin Rodriguez-Paez Vitamin D , along with diet and exercise, has emerged as one of the most important preventive factors i. … discovered that in cultured adrenal cells vitamin D increased the expression of tyrosine hydroxylase, which is the rate limiting enzyme responsible fordopamine production.9 …
Exercise regularly. Exercise increases blood calcium, which stimulates dopamine release and uptake in your brain. Try 30 to 60 minutes of walking, swimming or jogging to … Get plenty of sleep. One of the best ways to feel energized and ready to tackle the day is to get plenty of sleep. Dopamine has been tied to feelings of …
Dec 5, 2012 – Studies showed that exercise caused an increase of serotonin precursors, as well asdopamine, in the brainstem and the hypothalamus. These researchers stated that … If we lack sleep, are stressed, vitamin D deficient, etc. it may be a good idea to not exercise too strenuously. Also, we need to manage our …
Jan 11, 2011 – Sunlight exposure can benefit mood by boosting levels of key hormones and also by producing vitamin D. Vitamin D is produced in the liver and … So having increased dopamine levels should make you feel more euphoric and this is likely to be the pleasure we feel when we open the windows on a sunny …
Aug 21, 2008 – Just one night without sleep can increase the amount of the chemical dopamine in the human brain, according to new imaging research in the Journal of Neuroscience. Because drugs thatincrease dopamine, like amphetamines, promote wakefulness, the findings offer a potential mechanism explaining …
Jun 4, 2012 – “Evidence That Sleep Deprivation Downregulates Dopamine D2R in Ventral Striatumin the Human Brain” Journal of Neuroscience, 2012. There are lots of signs that point toward the involvement of the neurotransmitter dopamine in wakefulness. Drugs that increase levels of dopamine in brain (including, …
Nov 17, 2011 – The four ways to boost serotonin activity are sunlight, massage, exercise, and remembering happy events. At this point … However, UV is important because UV light absorbed through your skin produces Vitamin D. Vitamin D plays many roles in your body, including promotingserotonin production.