Albert Lab
Team Leader
Paul Albert
Senior Scientist, NeuroscienceWhat We Do
One key gene that we study is serotonin-1A (5-HT1A) receptor gene. The 5-HT1A autoreceptor on serotonin neurons inhibits their activity and is associated with depression and resistance to SSRIs. But in other brain cells, it mediates serotonin actions (see Figure below). The 3-6 week delay in response to SSRIs reflects the time it takes to desensitize the 5-HT1A autoreceptors to allow serotonin activation. Therefore, we first identified the molecular mechanisms that regulate the 5-HT1A gene and identified human 5-HT1A variant (rs6295) that increases 5-HT1A expression and is associated with SSRI-resistant depression. To test whether these transcription changes really affect depression we knocked them out in serotonin neurons of adult mice. This results in SSRI-resistant anxiety and depression-like behaviors.
We are now testing whether other types of antidepressants or direct stimulation of serotonin neurons will reverse the depression in these mice.In addition to genetic changes, we examine how sex and stress affect behavior and response to antidepressants. We find important roles of DNA methylation of the 5-HT1A gene and remodeling of serotonin branches in the brain. We have also examined depression that occurs after a stroke and that responds to SSRI treatment but not exercise. Using this injury model of depression, we are finding that SSRIs enhance neuroplasticity of serotonin branches (see Figure above) for long-lasting recovery from depression and cognitive impairment. By understanding antidepressant actions in these models, we can develop better treatment strategies for depression in humans.
Research Activities
A major goal of our research is to understand the mechanisms underlying depression including post-stroke depression and the therapeutic actions of antidepressants. To address factors that impact chronic depression we examine the mechanisms of functional promoter polymorphisms and chronic stress induced epigenetic modification actions on gene expression, behavior, and antidepressant response in humans and mouse models of mental illness. Our fundamental research has identified multiple molecular mechanisms that regulate key genes in mental illness including serotonin-5-HT1A; dopamine-DRD2; and 5-HT synthesizing TPH2 genes. We have identified novel DNA elements that regulate these genes, cloned the novel transcription factors targeting them, and identified new functional gene polymorphisms associated with mental illness (Albert, 2019). We have elucidated their roles in vitro, in mouse models and in humans.
For the 5-HT1A receptor, we identified rs6295 as a functional polymorphism associated with depression and suicide that leads to dys-regulation of receptor expression (Lemonde et al., 2003). We have shown changes in mental illness of RNA and protein expression of the 5-HT1A receptor and its key transcriptional regulators that we have identified, including Freud-1, Freud-2 and Deaf1. In mouse models we have shown that alterations in these transcription factors result in altered 5-HT1A expression, and antidepressant-resistant anxiety and depression phenotypes. Our current research addresses which treatments are effective in these mice (Vahid-Ansari et al. 2024). In addition, we have recently examined the DNA methylation patterns of the 5-HT1A promoter sites, and upstream sites recognized by these transcription factors (Albert et al., 2019). These studies demonstrate the potential to target multiple mechanisms to for treatment of mental illness.
We have also established a new mouse model of post-stroke depression that responds to antidepressants (Vahid-Ansari and Albert, 2018), which promote 5-HT re-innervation of the stroke site (Zahrai, 2020). We are currently addressing the role of this re-innervation in antidepressant actions using ontogenetic and gene knockout approaches. We are also examining the role of 5-HT innervation changes in other mouse models of depression including genetic, stress-induced, and depression associated with Parkinson’s and Alzheimer’s disease.
Selected Publications
Albert lab members in bold
Publications archived at: ResearchGate
1. Vahid-Ansari F, Newman-Tancredi A, Fuentes-Alvarenga AF, Daigle M, Albert PR (2024) Rapid reorganization of serotonin projections and antidepressant response to 5-HT1A-biased agonist NLX-101 in fluoxetine-resistant cF1ko mice. Neuropharmacology 261:110132. PDF
2. Vahid-Ansari F, Zahrai A, Daigle M, Albert PR (2024) Chronic Desipramine Reverses Deficits in Cell Activity, Norepinephrine Innervation, and Anxiety-Depression Phenotypes in Fluoxetine-Resistant cF1ko Mice. J Neurosci 44. PDF
3. Turcotte-Cardin V, Vahid-Ansari F, Luckhart C, Daigle M, Geddes SD, Tanaka KF, Hen R, James J, Merali Z, Beique JC, Albert PR (2019) Loss of adult 5-HT1A autoreceptors results in a paradoxical anxiogenic response to antidepressant treatment. J Neurosci 39, 1334-46. PDF
4. Vahid-Ansari F, Daigle M, Manzini MC, Tanaka KF, Hen R, Geddes SD, Beique JC, James J, Merali Z, Albert PR. (2017) Abrogated Freud-1/CC2D1A repression of 5-HT1A autoreceptors induces fluoxetine-resistant anxiety/depression-like behavior. J Neurosci 37, 11967-11978. PDF
5. Zahrai A, Vahid-Ansari F, Daigle M, Albert PR (2020) Fluoxetine-induced recovery of serotonin and norepinephrine projections in a mouse model of post-stroke depression. Transl Psychiatry 10:334. PDF