If you knew what stressors could develop into psychiatric disorders in humans, would you care to find out? Better yet, are you confined to your stressful environment or are there ways to adapt and persevere?
Nikolaos Daskalakis, a neuropsychopharmacologist at Leiden University,
may be able to tell you just how detrimental early life adversity can be on mental health and has possibly offered a solution to tackling early life stressors. Dr. Daskalakis' research focuses on the interaction between stress and the brain in health and disease. Turns out rat pups are great model organisms to understand stress systems in humans.
It has been shown that rat pups deprived of maternal care could be used to study the underlying mechanism of CORT-enhanced vulnerabilities--disorders due to an induced stress response--such as depression. When you are stressed, you release corticosterone (CORT) as well as adrenocorticotropin (ACTH) hormone. These two hormones are the basis of his study.
By studying the levels of both CORT and ACTH, Dr. Daskalakis could understand the effect of different stressors on the rat pups. He did not know, however, the extent to which the hypothalamus-pituitary-adrenal (HPA) axis is affected by maternal separation and whether or not there was a desensitization after prolonged exposure.
He decided to find out.
Dr. Daskalakis and his colleagues set up three different experiments to find out the immediate effects of daily repeated 8-hour maternal separation 3-5 days after parturition (birth) on Wistar and Long Evans rats.
There were two separation scenarios:
Experiment 1 determined the effect of repeated separations in different separation context on body growth, ACTH, and maternal care using a total of 12 litters with 8 pups in each.
Experiment 2 determined the effects of repeated separations in home context on adrenal activity using a total of 8 litters with 8 pups in each. The adrenal activity was determined by measuring levels of adrenal tyrosine hydroxylase (TH) and melanocortin receptor-2 (MCR-2).
Experiment 3 determined the effects of repeated separation in home context on ACTH and CORT secretion of another rat strain using a total of 13 litters with 16 pups in each.
Sadly, the pups had to be decapitated in order to collect blood and analyze the hormone levels. ACTH and CORT were measured using radioimmunoassay and adrenals were homogenized and western blots were performed to measure TH and MCR-2 levels. However, it was all for the greater good because the results obtained were incredible!
Dr. Daskalakis and his colleagues showed that adrenal corticosterone secretion is abolished if there is repeated maternal absence and that it is irrespective of genotype, separation environment or maternal care upon reunion. This shows that rat pups adapt to repeated daily separations because they learn to predict when they are to be reunited with the dam.
The findings, published in Hormones and Behavior, could have implications for both the anticipation of stress and the importance of attention during formative years. Being aware of when your stressor will end--in this case, maternal separation--completely abolishes your stress response. This could lead to research on proactive measures to acknowledge your stressors and therefore, minimize their impacts on your mental health and overall well-being. Studies have shown that recognizing your stressors "lets you pause your visceral reaction, allowing you to choose a more enhancing response."
What's more, it gives momentum to the idea that early childhood is paramount to the success of an individual. Early childhood development should be closely monitored and caregivers--whether it be maternal care, paternal care, or otherwise care in general--should implement healthy attachment mechanisms in an effort to prevent the development of psychiatric disorders. It has already been known that certain attachment styles have resulted in anxious and insecure relationships in later years.
We have a long way to figure out what exact stressors can lead to psychiatric disorders such as schizophrenia, major depression, PTSD, etc., but in knowing that stress responses can be mitigated with acknowledgement and awareness, we can remain hopeful that some of us do not have to be defined by our environment and that "it is not about the cards you're dealt but how you play the hand."
*all key terms are bolded and defined for clarification.
Key terms:
Adrenocorticotropin hormone: a hormone produced by the anterior pituitary that stimulates the production and release of cortisol (your "stress" hormone) from the cortex of your adrenal gland.
Corticosterone: the major stress hormone produced in the cortex of the adrenal gland.
Hypothalamus-Pituitary-Adrenal axis: a pathway that controls reactions to stress.
Tyrosine Hydroxylase: an enzyme that aids in the formation of catecholamines including dopamine, noradrenaline, and adrenaline.
Melanocortin Receptor-2: receptor specific to ACTH
Radioimmunoassay: a technique that measures antigen concentrations (for example, hormone levels in the blood) by use of labeled antibodies.
Western blotting: a technique used to identify specific amino-acid sequences in proteins (peptide hormones like the ones in this study).
Dam: pregnant or parent females
Nikolaos Daskalakis, a neuropsychopharmacologist at Leiden University,
It has been shown that rat pups deprived of maternal care could be used to study the underlying mechanism of CORT-enhanced vulnerabilities--disorders due to an induced stress response--such as depression. When you are stressed, you release corticosterone (CORT) as well as adrenocorticotropin (ACTH) hormone. These two hormones are the basis of his study.
By studying the levels of both CORT and ACTH, Dr. Daskalakis could understand the effect of different stressors on the rat pups. He did not know, however, the extent to which the hypothalamus-pituitary-adrenal (HPA) axis is affected by maternal separation and whether or not there was a desensitization after prolonged exposure.
He decided to find out.
Dr. Daskalakis and his colleagues set up three different experiments to find out the immediate effects of daily repeated 8-hour maternal separation 3-5 days after parturition (birth) on Wistar and Long Evans rats.
There were two separation scenarios:
- Home separation: pups remained in a familiar environment with their littermates.
- Novel separation: pups were moved to an unfamiliar environment but with similar conditions as the housing room.
Experiment 1 determined the effect of repeated separations in different separation context on body growth, ACTH, and maternal care using a total of 12 litters with 8 pups in each.
Experiment 2 determined the effects of repeated separations in home context on adrenal activity using a total of 8 litters with 8 pups in each. The adrenal activity was determined by measuring levels of adrenal tyrosine hydroxylase (TH) and melanocortin receptor-2 (MCR-2).
Experiment 3 determined the effects of repeated separation in home context on ACTH and CORT secretion of another rat strain using a total of 13 litters with 16 pups in each.
Sadly, the pups had to be decapitated in order to collect blood and analyze the hormone levels. ACTH and CORT were measured using radioimmunoassay and adrenals were homogenized and western blots were performed to measure TH and MCR-2 levels. However, it was all for the greater good because the results obtained were incredible!
Dr. Daskalakis and his colleagues showed that adrenal corticosterone secretion is abolished if there is repeated maternal absence and that it is irrespective of genotype, separation environment or maternal care upon reunion. This shows that rat pups adapt to repeated daily separations because they learn to predict when they are to be reunited with the dam.
The findings, published in Hormones and Behavior, could have implications for both the anticipation of stress and the importance of attention during formative years. Being aware of when your stressor will end--in this case, maternal separation--completely abolishes your stress response. This could lead to research on proactive measures to acknowledge your stressors and therefore, minimize their impacts on your mental health and overall well-being. Studies have shown that recognizing your stressors "lets you pause your visceral reaction, allowing you to choose a more enhancing response."
What's more, it gives momentum to the idea that early childhood is paramount to the success of an individual. Early childhood development should be closely monitored and caregivers--whether it be maternal care, paternal care, or otherwise care in general--should implement healthy attachment mechanisms in an effort to prevent the development of psychiatric disorders. It has already been known that certain attachment styles have resulted in anxious and insecure relationships in later years.
We have a long way to figure out what exact stressors can lead to psychiatric disorders such as schizophrenia, major depression, PTSD, etc., but in knowing that stress responses can be mitigated with acknowledgement and awareness, we can remain hopeful that some of us do not have to be defined by our environment and that "it is not about the cards you're dealt but how you play the hand."
*all key terms are bolded and defined for clarification.
Key terms:
Adrenocorticotropin hormone: a hormone produced by the anterior pituitary that stimulates the production and release of cortisol (your "stress" hormone) from the cortex of your adrenal gland.
Corticosterone: the major stress hormone produced in the cortex of the adrenal gland.
Hypothalamus-Pituitary-Adrenal axis: a pathway that controls reactions to stress.
Tyrosine Hydroxylase: an enzyme that aids in the formation of catecholamines including dopamine, noradrenaline, and adrenaline.
Melanocortin Receptor-2: receptor specific to ACTH
Radioimmunoassay: a technique that measures antigen concentrations (for example, hormone levels in the blood) by use of labeled antibodies.
Western blotting: a technique used to identify specific amino-acid sequences in proteins (peptide hormones like the ones in this study).
Dam: pregnant or parent females
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