L17 - Neuroplasticity Flashcards
What is neuroplasticity?
Refers to the brains ability to recognise and alter its anatomical and functional connectivity in response to environmental input
Why is neuroplasticity important in psychiatry?
It significantly impacts the manifestation and progression of clinical symptoms in many psychiatric illnesses
What’s structural neuroplasticity?
Changes in neuronal morphology (shape, structure and physical characteristics of neurons), cellular structures and connectivity
What’s functional neuroplasticity?
Dynamic changes in synaptic responsiveness, presynaptic neurotransmitter release, and intracellular signaling pathways
What’s a critical period?
A developmental phase when the brain is highly responsive to specific environmental stimuli, with long-lasting effects on neural pathways
what’s a sensitive period?
A time during development when the brain is particularly responsive experiences, but not rigidly constrained as critical periods
How does GABA influence critical periods?
GABA helps regulate the start and stop of critical periods by balancing excitatory and inhibitory signals in the brain
How is neuroplasticity linked to autism spectrum disorder (ASD)?
Aberrant neuroplasticity (unusual/ abnormal changes in the brain’s ability to adapt and recognise) in ASD often involves early brain overgrowth and an imbalance of excitation and inhabition
What structural changes are common in the brains of children with ASD?
By age 2-4 their overall brain volume is approx 10% larger than typically developing children
What role does GABA play is ASD?
Reduced GABAergic inhibition leads to lower signal-to-noise ratios, affecting neural processing and development
What is an excitation/ inhibition imbalance?
A disruption in the balance of excitatory and inhibitory signals, leading to excessive or diminished neuronal a neuronal activity
Which conditions are associated with excitation/inhibition imbalance?
ASD
Epilepsy
Schizophrenia
Alzheimer’s disease
Parkinson’s disease.
How does early adversity affect brain development?
Can lead to epigenetic changes and disruptions in emotion regulation, increasing the risk of psychopathology
How does trauma affect amygdala reactivity?
Maltreated youth show greater activation in the left amygdala and reduced activity in regions involved in cognitive control.
What’s the difference between tolerable and toxic stress?
Tolerable - managed and can be recovered from
Toxic - leads to prolonged disruptions in brain development
How does CBT reshape synapses?
CBT can reduce excessive neural reactivity in the amygdala –> promoting functional neuroplasticity in anxiety and social disorders
What brain changes were observed in anxiety patients after CBT?
Reduced amygdala reactivity and improved emotion regulation
where does adult neurogenesis occur in the brain?
In the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ) of the lateral ventricles
What happens to human hippocampal neurogenesis over time?
It drops sharply after childhood and becomes undetectable in adults
How does transcranial magnetic stimulation (TMS) influence neuroplasticity?
High frequency TMS increases neuronal activity
Low frequency TMS reduces neuronal excitability
How might TMS benefit individuals with ASD?
It may stabalize cortical hyperplasticity by potentiating inhibitory mechanisms
why is early intervention cruicial in neuroplasticity-based therapies?
Early experiences have long-lasting effects on brain structure and function, influencing outcomes in conditions like ASD and PTSD
How does experience shape neuroplasticity?
It stabilises frequently used synapses and prunes those that are unused, influencing learning and memory
What factors can disrupt neuroplasticity?
Malnutrition, emotional stress, oxidative stress, and immune challenges
What is the relationship between neuroplasticity and psychopathology?
Aberrant neuroplasticity can contribute to conditions like ASD, schizophrenia, and anxiety disorders, but targeted therapies can help reshape neural circuits.
Why does the ability to change brains decrease over time?
Neuroplasticity is most robust during critical periods in early life and diminishes with age.
