Adverse Childhood Experiences (ACEs) and Neurobiological Outcomes

Comprehensive vocabulary flashcards covering developmental stress models, fear conditioning mechanisms, PTSD neurobiology, and epigenetic transmission based on the lecture transcript.

ACEs (Adverse Childhood Experiences)

A category of early life stressors divided into three groups: abuse (physical, emotional, sexual), neglect (physical, emotional), and household dysfunction (mental illness, incarcerated relative, substance abuse, divorce, or intimate partner violence).

Cumulative damage

One of two ways ACEs exert their effects, referring to the build-up of impact over time rather than a single event.

Prenatal Model of Stress

Manipulating the environment of the mother during pregnancy through psychological (restraint), physical (hypoxia), social, or pharmacological (glucocorticoid administration) stressors.

Hypoxia

A physical stressor in prenatal models where body tissues do not receive enough oxygen.

Neonatal Handling

A postnatal model of early life stress where the pup is separated from the dam for $10-30\,min$ per day.

Maternal Separation (MS)

A postnatal stress model involving the separation of pups from the dam for $3-6\,hours$ per day.

Maternal Deprivation (MD)

An acute postnatal stressor consisting of a single $24\,hour$ separation period from the mother, resulting in no grooming or feeding.

Limited Bedding and Nesting (LBN)

A stress model characterized by fragmented and erratic nurturing behaviors from the dam, which increases stress hormones in both mother and pup.

USVs (Ultrasonic Vocalizations)

A measure of the fear response in rats; studies found that brief maternal separation reduced these conditioned responses to both context and cues.

Renewal

The relapse of fear following extinction when the subject is tested in a context different from the extinction context; observed in rats following chronic MS, acute MD, or chronic CORT treatment.

SAM Axis

The Sympathetic-Adrenal-Medullar axis; the initial, fast stress response where the hypothalamus activates the SNS to release epinephrine and norepinephrine from the adrenal medulla.

HPA Axis

The Hypothalamus-Pituitary-Adrenal axis; the second, slower stress response where CRH and ACTH trigger the release of glucocorticoids from the adrenal cortex.

Corticosterone (CORT)

The primary glucocorticoid stress hormone in rats which facilitates the formation of stress-related memories and is easily passed from a lactating dam to pups.

Stress Hyporesponsive Period (SHRP)

The first two weeks of life in rodents where circulating glucocorticoid levels remain low even in the face of stressors like restraint or shock.

Stress Acceleration Hypothesis

The theory that early-life adverse experiences lead to an adaptive but potentially maladaptive short-term acceleration in the maturation of brain circuits and behavior.

PI (Prolonged Institutional) Rearing

An atypical caregiving environment (such as an orphanage) associated in humans with atypically large amygdala volume and difficulties in emotion regulation.

Criterion B (PTSD)

A core diagnostic criterion for PTSD referring to intrusion or re-experiencing symptoms, such as unwanted memories, flashbacks, or nightmares.

Extinction Recall Deficit

A characteristic of PTSD where subjects show lesser activation in the hippocampus and vmPFC, but greater activation in the dACC, when trying to remember extinction training.

Consolidation

The neurobiological process of stabilizing a memory trace after it is initially acquired.

Reconsolidation

The process where a retrieved memory becomes labile (unstable) and requires new protein synthesis to be restabilized.

Anisomycin

A protein synthesis inhibitor that, when injected into the BLA after memory retrieval, prevents reconsolidation of fear memories.

MDMA (Methylenedioxymethamphetamine)

A substance that facilitates fear extinction learning by increasing $BDNF$ signaling in the amygdala.

Fear Conditioning by Proxy

The social transmission of fear through observational learning, where an observer exhibits fear after watching a demonstrator receive shocks paired with a stimulus.

Intergenerational Transmission

The transfer of trauma effects to the $F1$ or $F2$ generations who were directly or indirectly exposed to the stressor (e.g., as germ cells).

Transgenerational Transmission

Stress effects that persist into the $F3$ generation and beyond, affecting individuals who were never physically present during the initial trauma.

Epigenetics

Changes in gene expression that do not involve alterations to the underlying DNA sequence, such as DNA methylation or histone acetylation.

Euchromatin

The open, relaxed state of chromatin where genes are transcriptionally active.

Heterochromatin

Tightly packed chromatin where genes are silenced or transcriptionally inactive.

DNA Methylation

An epigenetic modification that usually "turns off" genes by silencing transcription.

MSUS Model

Maternal Separation and Unpredictable Stress; a laboratory model demonstrating that depressive-like behaviors and metabolic changes can persist for up to 4 generations ($F4$).