46 terms

Psych 469 Final Exam Vocab

STUDY
PLAY
Epigenesis
Development in context- genes and environment
Reductionism
The act of describing a complex concept, such as epigenetic change in phenotype, using a basic/simple definition.
Bidirectionality
Mutual influence of genes, enviro, behavior etc on each other
Preformationism
development occurs only through growth of preformed parts - outdated view - opposes epigenetics
Probabilistic Epigenesis
epigenesis with bidirectionality
Predetermined Epigenesis
epigenesis with one way flow of influence and info from genes to nervous system to behavior
Vagal tone
effect of vagus nerve to decrease heart rate and increased HR variability at rest
Vagal brake
myelinated vagus nerve keeps HR low and variable - removing brake will cause HR to return to higher natural state w/out having to involve the SNS
RSA suppression
supression of variability in heart rate - steady heart rate = consistent flow of blood to the brain in stress situations. Respiratory sinus arrhythmia (RSA) is a naturally occurring variation in heart rate that occurs during a breathing cycle
Social engagement
This is moderated by the parasympathetic nervous system (PNS). The PNS allows energy to be devoted to cognition and focus, as opposed to energy being devoted to pumping blood and getting oxygen in in the case of a fight-or-flight response. The PNS is evolutionarily valuable because it allows individuals to be engaged with social behaviors, and form bonds potentially useful for survival. Myelinated branch of the vagus
Ingestive vagal reflex
newborns remove vagal brake when suckling/feeding to support metabolic demands of sucking, swallowing, and breathing
D1 like receptors
excitatory dopaminergic receptor
D2-like receptors
inhibitory dopaminergic receptor. lower availability of these receptors (or reduced binding efficiency) may translate into less behavior control → DRD2 & DRD4 polymorphism associated with impulsivity and low inhibition. Taq1 A1/DRD2 - Single nucleotide polymorphism (or SNP) - decreased D2 receptor density. L-DRD4 - Long/Short (tandem repeats) - affects structure of receptor and decreases binding affinity of the D4 receptor
HPA axis
Hypothalamic-Pituitary-Adrenal Axis - slow acting, releases glucocorticoids from adrenal glands to affect gene transcription - for uncontrollable stressors - long term
Negative feedback
This is the process in which enough of a product being bound to its receptors causes a signal to be released to stop the system from progressing. In the context of the class, when enough cortisol binds to glucocorticoid receptors, an inhibitory GABA signal is released to the hypothalamus to tell it to stop producing corticotropin releasing hormone (CRH).
Glucocorticoid receptor
These receptors are involved in the HPA Axis pathway of the Stress Response System, and are expressed on most organs in the body. Glucocorticoid receptors bind the ligand Glucocorticoid (like cortisol) to mediate cardiovascular activity, immune response, metabolism, oxygen intake, during points of stress. Increased numbers of Glucocorticoid receptors are correlated with increased levels of maternal care in infancy and decreased levels of methylation at the exon 1-7 promoter region of DNA (the promoter region of the glucocorticoid receptor gene). When enough cortisol (or other glucocorticoid) has bound to enough receptors, a message is sent to the hypothalamus to stop producing CRH, the hormone that, through another pathway, signals the production of cortisol.
Handling research
rat study on whether handling at critical infact age influenced the development of the HPA axis (later found to be due to augmentation of maternal care)
Maternal mediation
Theory by Levine and Bell that not the handling but the increase in maternal care is what prompted early HPA axis development in rats
Direct action hypothesis
Handling directly affects the HPA axis development because it induces fear or hypothermic shock from being away from the mother
Transcription factor
Something that regulates gene transcription by either turning on or off a gene transcribing mRNA. This is Stat5 in the prolactin-estrogen receptor pathway and NGF1-A in the maternal care - serotonin - GPCR pathway.
CBP
CREB-Binding Protein, forms a complex with NGF1-A in the Serotonin 5-HT pathway. The formation of this complex allows the complex to enter the nucleus and also signals for the presence of HATs, which open the chromatin to allow for the complex to act as a transcription factor and transcribe mRNA (more Glucocorticoid receptors).
Histone acetylation
Histone acetylation is associated with the activation of the transcription of a gene's associated mRNA. Histone acetylation in the maternal care/serotonin pathway is achieved by HATs (histone acetyl transferase), which add acetyl groups to the tails of histones associated with DNA in chromatin. Histone acetylation neutralizes the positive charge of the histones, weakening the bond it has with the negatively charged DNA, so that transcription factors and other associated molecules such as RNA polymerase can more efficiently transcribe the DNA sequence acetylated.
Nucleosome
The subunit of chromatin, comprised of 8 histones and two turns of DNA wrapped around.
Hippocampus
The part of the brain associated with emotion, memory, and the autonomic nervous system. Deeply involved with the SNS. Particularly, glucocorticoid receptors in the hippocampus as they are associated with the HPA Axis are highly sensitive to cortisol levels.
CRH and CRH mRNA
Corticotropin Releasing Hormone = CRH. CRH mRNA is the RNA the DNA produces when it is transcribed, before it is moved to a ribosome to produce the protein CRH. CRH is produced in the hypothalamus when the HPA Axis is activated via the portal vein. The pituitary responded to CRH by releasing ACTH (adrenocorticotropic hormone), which stimulates the adrenal cortex to release cortisol.
Cyclic-AMP
JLG: No, it recruits PKA to phosphorylate CBP and promote its dimerization with NGF-1A
Primary-messenger
The messenger system involved with the outer part of the cell before entering the nucleus.
JLG
Includes maternal licking down to the preparation of cAMP (which begins 2nd messenger)
HATs
Histone Acetyl Transferase. After adenylyl cyclase is bound by the alpha subunit in the serotonin 5-HT pathway, cAMP is produced, which energizes NGF1-A to enter the nucleus and move to the promoter region as a second messenger system. cAMP activates protein kinase A, which phosphorylates CBP, which can bind to NGF1-A as a complex to enter the nucleus. The binding of CBP and NGF1-A recruits HATs to open the chromatin by adding acetyl groups to the histone tails of the chromatin and neutralizing the positively charged histones. In their neutralized state, the histones are not as strongly associated with the DNA and transcription can occur most effectively.
Histone tails
The part of the histone that becomes either methylated or acetylated to activate or repress transcription (of in this case GC receptors or estrogen(?) )
GCmRNA
The RNA of the glucocorticoid receptors, which is sent to a ribosome to produce new glucocorticoid receptors. The ability of transcription factors to produce GCmRNA (or any mRNA) is based on the level of methylation of the promoter region of an organism's gene of interest. The more methylated a gene is, the less it is transcribed and the less mRNA is produced.
Canalization
The ability of a population to produce the same phenotype regardless of the variability of the environment or the population's genotype. Also called robustness.
Phosphorylation
The process in which phosphorous is added to a molecule that usually already contains phosphorus, to change its conformation and move a signaling pathway along.
Secondary-messenger
In the 5-HT Serotonin pathway, this is the NGF1-A and the cAMP complex, which translocate from the outside to the inside of the nucleus. In a signaling pathway, the secondary-messenger is the ligand that transfers a signal originating from a ligand and receptor binding on the surface of the cell to inside the nucleus, to directly impact transcription through repression or activation.
HDACs
Histone DeAcetylase - Recruited when the histones on the promoter regions are methylated, as is the case with rat pups born to low-licking mothers. HDACs remove Acetyl groups on the Histones, returning the histone to its unmodified state of being positively charged and tightly bound to the DNA.
CpG islands
The part of the DNA that is rich in cytosine and guanine nucleotide base pairs. This is also the part of the DNA that is selected for methylation.
Adrenal gland
This is the main actor in the HPA Axis. The Cortex of the Adrenal Gland releases glucocorticoids such as cortisol. Cortisol binds to Glucocorticoid Receptors throughout the body to impact cardiovascular activity, appetite, metabolism, immune response, electrolytic balance, and cognitive functions and behavior. Furthermore, binding of cortisol to GC Receptors is involved in a negative feedback loop -- such that if enough cortisol binds to GC Receptors in the body, a message will be sent to the Hypothalamus to stop the production of CRH.
ACTH
Adrenocorticotropic hormone, released from the pituitary in response to adrenalin. ACTH activates the HPA Axis and the release of cortisol.Adrenalin, not ACTH, activates the HPA axis when it binds to receptors in the hypothalamus (paraventricular nucleus) which then release ACTH to the anterior pituitary
Dissolution principle
JLG: No. it simply says that the various branches of the SRS are recruited in the inverse order of their phylogenetic origin (most recent first)
Transcript/translation
Transcription is the act of reading DNA and producing
RNA (often mRNA). Transcription is most often accomplished by transcription factors, which regulate the transcription of a gene by turning the gene on or off, and the actual act of reading the nucleic acids is done oftentimes by RNA Polymerase II. Translation is the act of taking mRNA to a ribosome and producing some kind of protein/hormone built by amino acid chains.
Serotonin (5-HT)
released in the infant rat's brain when mothers perform licking, grooming, and arched back nursing (LG-ABN) behaviors, mediates the relationship between maternal care and upregulation of GC receptors
GPCR
G-Protein Coupled Receptor -- used in the 5-HT Serotonin pathway. The GPCR is the receptor and 5-HT Serotonin is the ligand.
Promoter exon 17
The promoter of the glucocorticoid gene. The level of methylation of this promoter region depends on the level of maternal care an individual experiences (more maternal care = less methylation).
Methylation
Methylation is the repressive epigenetic control of the genome. Methylation also occurs in DNA on CpG islands → This recruits other proteins (MeCP2, HDACs) to the methylated DNA sites preventing transcription factors from binding by removing acetyl groups from histone tails.
Chromatin structure
This refers to the coupling of genetic information (DNA) and protein complexes called histones. There are 3 levels of organization of Chromatin. 1) DNA is wrapped around nucleosomes, comprised of 8 stacked histones. 2) Nucleosomes are further compressed by getting coiled into a fiber of 6 nucleosomes per turn. 3) Chromatin rests on a backbone that allows for supercoiling to produce the full chromosome.
Epigenetic regulation:
Going beyond the genetic makeup passed down from the mixture of mother and father DNA at birth. Epigenetic regulation indicates how your genome changes based on experiences that occur during your lifetime.
YOU MIGHT ALSO LIKE...