Antigravity Agent
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10_Wiki/Topics 대규모 정리: - 오류 캡처/미완성 stub 문서 227개 제거 - 교차폴더 중복 43클러스터 병합 (63파일 → redirect) - 링크명 정규화: 깨진 링크 수정·redirect 직결·개념 매핑 ~2,400건 - 카테고리 MOC 6개 신규 생성 - Graph 섹션 미해결 related-keyword 링크 10,058건 제거 Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
128 lines
4.7 KiB
Markdown
128 lines
4.7 KiB
Markdown
---
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id: wiki-2026-0508-neuroplasticity
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title: Neuroplasticity
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category: 10_Wiki/Topics
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status: verified
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canonical_id: self
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aliases: [Neuroplasticity, Brain Plasticity, Synaptic Plasticity]
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duplicate_of: none
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source_trust_level: A
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confidence_score: 0.9
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verification_status: applied
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tags: [neuroscience, plasticity, hebbian, ltp, critical-period, learning]
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raw_sources: []
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last_reinforced: 2026-05-10
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github_commit: pending
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tech_stack: { language: python, framework: brian2-pytorch }
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---
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# Neuroplasticity
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## 매 한 줄
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- 신경가소성은 시냅스·회로 수준에서 경험에 따라 신경계 구조·기능이 변화하는 능력이며, LTP/LTD가 분자 기반이다.
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## 매 핵심
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- **Hebbian rule**: "fire together, wire together" — pre/post synaptic 동시 발화 시 시냅스 강화.
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- **LTP/LTD**: NMDA receptor 매개 Ca²⁺ → CaMKII (LTP, 강화) vs calcineurin (LTD, 약화). hippocampus CA1, cortex L2/3에서 잘 연구됨.
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- **Critical period**: 시각피질 monocular deprivation 효과는 어린 시기 강함. parvalbumin GABA 성숙이 닫힘 trigger. 성인기 reopen에 chondroitinase, fluoxetine, dark exposure.
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- **Adult plasticity**: motor learning, taxi driver hippocampus 부피 증가, training-induced cortical map remodeling.
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- **AI 연결**: STDP(spike-timing dependent plasticity)는 SNN 학습 규칙, BCNN의 Hebbian feature learning에 영감.
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## 💻 패턴
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```python
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# STDP weight update rule
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import numpy as np
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def stdp(dt, w, A_plus=0.01, A_minus=0.012, tau_plus=20e-3, tau_minus=20e-3, w_max=1.0):
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if dt > 0: # post after pre → LTP
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dw = A_plus * np.exp(-dt / tau_plus)
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else:
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dw = -A_minus * np.exp(dt / tau_minus)
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return np.clip(w + dw, 0, w_max)
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```
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```python
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# Hebbian learning in linear neuron (Oja's rule, normalized)
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import numpy as np
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def oja_update(w, x, y, lr=0.01):
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return w + lr * (y * x - y ** 2 * w)
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```
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```python
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# LTP induction: theta-burst stimulation pattern generator
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def theta_burst(duration_s=2.0, burst_hz=5, pulses_per_burst=4, intra_hz=100):
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times = []
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t = 0.0
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while t < duration_s:
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for k in range(pulses_per_burst):
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times.append(t + k / intra_hz)
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t += 1 / burst_hz
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return times
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```
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```python
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# Synaptic scaling (homeostatic plasticity)
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import numpy as np
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def synaptic_scaling(W, target_rate, actual_rate, tau=1000.0):
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factor = target_rate / (actual_rate + 1e-6)
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return W * (1 + (factor - 1) / tau)
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```
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```python
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# Brian2: STDP synapse simulation
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from brian2 import *
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G = NeuronGroup(2, "dv/dt = -v/(10*ms) : 1", threshold="v>1", reset="v=0")
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S = Synapses(G, G,
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"""w : 1
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dApre/dt = -Apre/(20*ms) : 1 (event-driven)
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dApost/dt = -Apost/(20*ms) : 1 (event-driven)""",
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on_pre="""v_post += w
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Apre += 0.01
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w = clip(w + Apost, 0, 1)""",
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on_post="""Apost -= 0.012
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w = clip(w + Apre, 0, 1)""")
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S.connect(i=0, j=1)
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```
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```python
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# Cortical map plasticity index from receptive field overlap
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import numpy as np
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def map_plasticity(rf_pre, rf_post):
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overlap = np.minimum(rf_pre, rf_post).sum() / np.maximum(rf_pre, rf_post).sum()
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return 1 - overlap # higher = more remodeling
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```
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```python
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# BDNF-dependent plasticity: serum BDNF as biomarker proxy
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def plasticity_score(bdnf_ng_ml, exercise_min_week, sleep_hr):
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# toy index, not clinical
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return 0.4 * bdnf_ng_ml / 30 + 0.3 * min(exercise_min_week, 300) / 300 + 0.3 * min(sleep_hr, 8) / 8
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```
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## 매 결정 기준
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- **개입 시기**: critical period 진행 중이면 sensory restoration(eg. amblyopia patching) 효과 큼.
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- **약리 보조**: 성인 plasticity 재개에 SSRI(fluoxetine), tDCS, aerobic exercise(BDNF↑).
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- **학습 설계**: spaced repetition(LTP consolidation), sleep 보장(systems consolidation).
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- **연구 모델**: in vitro slice → LTP/LTD 측정. in vivo two-photon → spine turnover.
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## 🔗 Graph
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- 관련: [[Neurorehabilitation-Post-Stroke]], [[Neurodevelopmental-Disorders]], [[Neuroprosthetics-Development]], [[Hebbian-Learning]]
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## 🤖 LLM 활용
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- 학습 곡선 데이터에서 plasticity phase 추정(initial vs consolidation).
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- 논문 요약: LTP 분자 경로 다이어그램 생성.
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- 실험 설계 review(빠진 control 식별).
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## ❌ 안티패턴
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- "성인 뇌는 변하지 않는다" 신화 인용.
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- STDP를 단순 Hebbian과 동일시(타이밍 차이 핵심).
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- BDNF 보조제 임의 권고(증거 부족).
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## 🧪 검증
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- LTP: fEPSP slope baseline 대비 +30% 30분 이상.
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- 행동: motor task 학습률, cortical map fMRI pre/post.
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## 🕓 Changelog
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- 2026-05-08 Phase 1: 초안 자동 생성.
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- 2026-05-10 Manual cleanup: 본문 보강, STDP/Oja/Brian2 코드 추가, critical period reopen 약리 반영.
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