Q: Define neuroplasticity and distinguish synaptic, circuit, and network plasticity with examples relevant to therapy. 🧠🔄🔗🧩🌐✨
A:
Neuroplasticity = the nervous system’s capacity to change structure/function in response to experience 🔄🧠🌱✨.
Synaptic plasticity 🔗⚡: change in strength of a single connection (e.g., stronger “safe” association at a cue synapse) ✅🧠🛡️
Circuit plasticity 🧩🧠: change in interaction between regions (e.g., stronger vmPFC inhibition of amygdala) 🛑😨➡️🧘🧠
Network plasticity 🌐🧠: change in broader coordination (e.g., executive-control networks becoming more dominant over threat/salience networks during regulation) 👩⚖️🧠⬆️😱📉🎛️✨.
Q: What is glutamate, and why is it the “core currency” of learning at synapses? 🧠⚡🧪💱🔗✨
A:
Glutamate is the brain’s main excitatory neurotransmitter ⚡🧠🔥. Most long-term learning depends on altering glutamatergic synapses because:
excitatory synapses are widespread in cortex/hippocampus/striatal inputs 🌍🧠📡
plasticity rules (LTP/LTD) largely operate through glutamate receptors (AMPA/NMDA) 🚪🧠 and downstream Ca²⁺ signalling 🧲🧪 that produces lasting changes in synaptic efficacy ⏳🔗✨🧠.
Q: What does AMPA do at a synapse (physiology), and how should you describe it in an exam? 🧠🚪⚡🧂📝✨
A:
AMPA receptors are glutamate receptors that mediate most fast excitatory synaptic transmission ⚡⚡🏃♂️💨:
glutamate binds AMPA → channel opens quickly ⏩🚪 → Na⁺ influx 🧂⬅️⬅️ (and some K⁺ efflux) ➡️ → rapid EPSP ⚡ (postsynaptic depolarisation) 🔋📈
Exam phrasing: AMPA carries most fast excitatory current ⚡🧠 and contributes to depolarisation that can help enable NMDA activation 🔓🧲✨.
Q: What makes NMDA receptors special, and why are they called “coincidence detectors”? 🧠🧲🔍⚡🤝✨
A:
NMDA receptors are glutamate receptors that require two conditions ✅✅ to conduct significantly:
Glutamate present (presynaptic activity) 🧪➡️🧠
Postsynaptic depolarisation (postsynaptic neuron already active) 🔋⚡
This means NMDA effectively detects co-activity 🤝🧠: “pre is talking while post is active.” That is the classic definition of a coincidence detector 🎯🔍✨, linking experience (co-activation) to plasticity 🔄🧠💥.
Q: Explain “NMDA needs depolarisation” in an easy mechanism chain (what supplies the depolarisation, and why it matters). 🧠🔓🔋➡️🧲✨
A:
NMDA channels are effectively blocked at resting potential 🚫🔌; depolarisation relieves this block 🔋✅. Mechanism chain ⛓️🧠:
presynaptic glutamate release activates AMPA first 🧪➡️🚪⚡
AMPA produces a fast EPSP → depolarises postsynaptic membrane ⚡🔋📈
with depolarisation + glutamate bound ✅✅, NMDA can conduct 🔓🧲
Result: NMDA opens mainly when synapses are active and the postsynaptic neuron is sufficiently depolarised 🎯🧠⚡, which is exactly the condition for associative learning 🤝📚✨.
Q: Why is Ca²⁺ entry via NMDA the key “learning trigger” rather than just another ion movement? 🧠🧲🧪🔑✨
A:
When NMDA opens 🔓🧲, it allows Ca²⁺ influx 🧲⬅️. Ca²⁺ is a second messenger 📩🧪:
it triggers intracellular cascades (kinases/signalling pathways) 🧬⚙️📡
these cascades change the synapse long-term by altering receptor trafficking and synaptic structure 🔁🚚🚪🧠🏗️
So Ca²⁺ is the “convert a moment into a memory” signal ⏱️➡️🧠💾✨ that initiates long-term synaptic change 🔄🔗💥.
Q: Define LTP and give an exam-safe stepwise mechanism linking NMDA/Ca²⁺ to AMPA changes. 🧠📈🧲🧪🚪✨
A:
LTP (Long-Term Potentiation) = persistent increase in synaptic strength 📈🔗✨.
Exam-safe mechanism 🧠📝:
Strong/coincident pre- and postsynaptic activity 💥🤝🧠
NMDA opens → Ca²⁺ influx 🔓🧲⬅️
Ca²⁺ signalling → promotes AMPA receptor insertion/increased AMPA efficacy 🚚➡️🚪⬆️⚡
Next glutamate release → bigger EPSP ⚡📈 → synapse strengthened 💪🔗✨
Core summary: LTP = NMDA-dependent Ca²⁺ → AMPA ↑ → stronger synapse. 🧠🧲🧪➡️🚪⬆️➡️🔗💪
Q: Define LTD and link it to AMPA changes (exam-safe). 🧠📉🚪⬇️✨
A:
LTD (Long-Term Depression) = persistent decrease in synaptic strength 📉🔗.
Exam-safe idea 🧠📝:
particular patterns of activity yield Ca²⁺ signals that favour weakening 🎚️🧲📉
downstream signalling results in AMPA receptor removal/reduced AMPA efficacy 🚚⬅️🚪⬇️⚡
Core summary: LTD = AMPA ↓ → weaker synapse. 🚪⬇️➡️🔗📉✨
Q: What is the simplest receptor-level statement linking therapy to synaptic change (Part A)? 🧠🗣️➡️📚➡️🧬✨
A:
Therapy drives learning 🗣️📚🧠; learning changes synapses via NMDA-dependent Ca²⁺ signalling 🧲🧪🔑, which causes lasting synaptic modification largely through AMPA receptor trafficking 🚚🚪 (insertion for strengthening ⬆️💪; removal for weakening ⬇️📉).
Q: What are dendritic spines, and why do they matter for long-term learning/therapy effects? 🧠🌵🔗✨
A:
Dendritic spines are small postsynaptic protrusions on dendrites 🌵🧠 where many excitatory synapses sit 🔗⚡. They matter because:
spine formation/stabilisation can represent creation/maintenance of synaptic connections 🏗️🔗✅
learning can alter spine number, size, and stability 🔢📏🧷✨
these structural changes help “lock in” learned patterns beyond short-term receptor changes 🔒🧠💾⏳.
Q: Explain the relationship between functional plasticity (receptors) and structural plasticity (spines) in a simple way. 🧠🚪🔄🌵🏗️✨
A:
Functional plasticity changes how strongly a synapse works (AMPA/NMDA) 🚪⚡. With repetition 🔁, these functional changes can be accompanied by structural changes 🏗️:
strengthened synapses are more likely to have stabilised/enlarged spines ✅📈🌵
weakened synapses may show spine shrinkage/loss 📉🌵➡️❌
So short-term “signal strength” changes ⚡ can become longer-term “wiring” changes 🧠🧵🔧✨.
Q: What is synaptic pruning, and how should you describe its relevance to adult therapy without overclaiming? ✂️🧠🔗⚖️✨
A:
Pruning = reduction/elimination of less-used synapses ✂️🔗. It is most prominent in development 👶🧠, but adults still show experience-dependent strengthening and weakening of connections 🔄💪📉. Exam-safe therapy link 🧠📝:
repeated practice strengthens relevant pathways 🔁✅🛣️💪
reduced use of maladaptive pathways can weaken them over time ⬇️🛣️⏳
Avoid overclaim 🚫📣: don’t say “therapy deletes memories”; say it alters strength/availability of pathways 🧠🔗🎚️.
Q: What is myelination and how can it relate to learning/therapy at an exam-safe level? 🧠🧵⚡⏩✨
A:
Myelin insulates axons 🧵🛡️, increasing conduction speed ⚡⏩ and timing precision 🎯⏱️, supporting efficient circuit communication 🧩📡. Exam-safe link 🧠📝:
repeated practice/skill learning can be associated with activity-dependent changes that improve efficiency of relevant pathways (don’t overspecify) 🔁🏋️♂️🧠⚡✨.
Q: What’s the key distinction between “glutamate plasticity machinery” and “neuromodulators” in learning? 🧠⚡🎛️🖊️✨
A:
Glutamate (AMPA/NMDA) provides the main synaptic transmission and plasticity mechanism (“the pen that writes changes”) 🖊️🧠📜. Neuromodulators (DA/NA/5-HT/GABA) adjust 🎛️:
what gets prioritised ⭐🎯
how strongly learning occurs 🔊📈
stability/inhibition 🛡️🛑
They act like “volume knobs/highlighters” 🔊🖍️✨ for plasticity rather than encoding the content alone 📌🧠.
Q: Define prediction error and explain how dopamine neurons encode it (burst vs dip) at Part A depth. 🧠⚡🎯📈📉✨
A:
Prediction error = actual outcome − expected outcome ➖🧮🎯.
If outcome is better than expected ✅⬆️ → positive prediction error ➕🎯 → dopamine neurons show a phasic burst 💥⚡ → promotes strengthening of the predictive cue/action link 🔗💪
If outcome is worse than expected ❌⬇️ → negative prediction error ➖🎯 → dopamine neurons show a phasic dip/pause 📉⏸️ → promotes weakening/suppression of that link 🔗⬇️🛑
Key exam pattern 📝: as learning occurs, dopamine response shifts from outcome 🎁 to the cue 🔔 that predicts the outcome; if expected outcome fails to appear, dopamine dips at the expected time ⏱️📉.
Q: Where do prediction-error dopamine signals originate, and what does “phasic dopamine” mean? 🧠🧪⚡⏱️✨
A:
Midbrain dopamine systems 🧠🌌:
VTA (often reward/valuation learning; ventral striatum) 🎁⭐➡️🧠
SNc (often action/habit learning; dorsal striatum) 🏃♂️🔁➡️🧠
Phasic dopamine = brief bursts/dips in firing over ~hundreds of ms to seconds ⏱️⚡📈📉, acting as a teaching signal 👨🏫🧠 (distinct from tonic baseline levels 📏).
Q: Mechanistically, how does dopamine change learning at synapses (MOA) in a simple but accurate way? 🧠🔗⚡🧪🎯✨
A:
Dopamine modulates plasticity at cortico-striatal glutamate synapses 🧠➡️🎯🔗:
glutamate from cortex carries “what was active” (cue/action/thought) 🧪🧠💭
dopamine arriving around the same time marks the event as needing updating and biases whether synapses strengthen or weaken ⏱️🎯📈📉
At Part A level: phasic dopamine biases LTP/LTD at cortico-striatal synapses, shaping reinforcement and habit learning 🏆🔁🧠✨.
Q: What are D1 vs D2 pathways in the striatum, and how do they link to reinforcement learning (exam-safe)? 🧠🎯🟢🔴✨
A:
Two major striatal outputs 🧠🎯:
D1 (direct pathway) 🟢: tends to support “Go/approach” reinforcement; dopamine bursts facilitate strengthening of recently active pathways (“do that again”) 💥➡️💪🔁
D2 (indirect pathway) 🔴: tends to support “No-Go/suppress” learning; dopamine dips help weaken/suppress recently active pathways (“don’t do that”) 📉➡️🛑⬇️
Exam-safe phrasing 📝: dopamine signals bias plasticity differently in D1 vs D2 circuits, enabling reinforcement learning 🎯🏆🧠.
Q: How does noradrenaline influence learning, and why is the inverted-U important for therapy? 🧠⚡📈📉🎢✨
A:
Noradrenaline controls arousal, attention, and salience (“this matters—encode it”) ⚡👀⭐. Inverted-U 🎢:
too low arousal 💤⬇️ → poor engagement/encoding 📉🧠
moderate arousal 🙂⚖️ → optimal learning/updating 📈🧠✨
too high arousal 😱🔥⬆️ → overwhelm/panic → reduced flexible updating 📉🧠🛑
Therapy aims for tolerable arousal to maximise learning 🧘🎯📈.
Q: What is serotonin’s exam-safe role in learning/therapy, and what is the key trap? 🧠🧪🔄⚠️✨
A:
Serotonin modulates emotional processing, behavioural flexibility, and PFC–limbic balance (supports regulation and flexible updating) 🎭🔄🧠⚖️. Trap ⚠️: “serotonin = happiness.” Correct ✅: it’s a broad modulator of affective learning/regulation, not one emotion 🌈🧠.
Q: What is GABA’s role in therapy-relevant physiology beyond “sedation”? 🧠🛑🛡️🎛️✨
A:
GABA is the main inhibitory transmitter 🛑🧠. It provides:
circuit stability (prevents runaway activation) 🛡️🚫🔥
gating/noise filtering 🚪🔇
supports top-down control by enabling inhibition of excessive threat/interoceptive responses ⬇️😨🫀🧠
Trap ⚠️: “GABA only = sedation.” Correct ✅: it underpins inhibitory control and circuit regulation 🎛️🛑✨.
Q: Describe the amygdala’s role in therapy-relevant neurobiology and typical symptom links. 🧠😨🚨✨
A:
Amygdala supports threat detection 🚨😨 and learned fear expression 🧠➡️😱; drives autonomic/defensive responses 🫀🏃♂️🛡️. Symptom links: cue-triggered fear 🔔😨, hypervigilance 👀⚠️, avoidance 🚪🏃♂️, conditioned threat responding 🔁😱.
Q: Describe the insula’s role and how it appears in panic/anxiety stems. 🧠🫀🌡️😱✨
A:
Insula represents interoception (body sensations → subjective feeling states) 🫀🌡️➡️😟. In panic, bodily sensations are misinterpreted as threat 😱⚠️. Stem cue 📝: “focus on heartbeat/breath + catastrophic interpretation” → insula + threat circuit 🫀👀➡️😨🧠.
Q: Describe the hippocampus’s role in therapy and why context matters for relapse. 🧠🗺️⏱️🔁✨
A:
Hippocampus encodes contextual memory (where/when) 🗺️⏱️. Fear/safety learning can be context-specific 🏷️; switching contexts can unmask old fear (renewal) 🔁😨. Stem cue 📝: “better in clinic, worse outside/new place” → hippocampus context gating 🏥✅➡️🏙️😨.
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CN3 OCCULOMOTOR55
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CN4 TROCHLEAR51
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Trigemnial nerve154
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FACIAL NERVE75
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VESTIBULOCOCHLEAR NERVE94
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GLASSOPHARYNGEAL50
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VAGAS78
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ACCESSORY59
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Hypoglossal84
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Midbrain65
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PONS80
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Medulla151
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Cerebellum100
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Dexcending pyrMIDl trCT17
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Cerebellar tract95
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Cerebellar cells44
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Efferent Cerebellar tract59
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Cerebellar lesions92
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Spinal chord anatomy132
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Cerbrovascular circ151
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CNS Cells236
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Cerebral neocortex cells249
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Bloodbrain barrier29
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CSF system55
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Action potential and synapse115
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white matter tracts71
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Cerbral cortex layers225
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Synapses47
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plasticity etc83
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meurogenesis and migration0
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Cortisol + CCK35
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Ghrehlin/Leptin103
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Endocannabinoids31
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Endokephalin/Endorphins73
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Orexin49
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3.3.6 Links between neurotransmitter systems and findings from genetic association studies in psychiatry.178
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high yeild31
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neural circuit - appetite175
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neural circuit - thirst72
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neural circuit - aggression153
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neural circuit - pain111
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learning100
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Habit and compulsions148
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Motivation, reward and pelasure147
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emotional regulation109
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perception135
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executive function + empathy/tom211
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DMN and Salience118
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Basic concepts: chromosomes, cell division, gene structure, transcription and translation,19
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structure of the human genome, patterns of inheritance.29
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Neurodevelopmental models40
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neurodev model88
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neurobiology of attatchment102
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neurodev model88
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stress182
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CBT128
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attatchment53
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Learning and therapy41
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neurobio learning39
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LEARNING THERAPY40
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LEARNING41
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Brain injury86
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Alzheimer's58
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Vascular0
