Upload
others
View
0
Download
0
Embed Size (px)
Citation preview
Limbic 1
心?情緒? 神經生物學基礎?
NH3 Fragrance: Fried chicken Perfume
Olfactory nerve
Motor pathways Emotional responses
? Optic nerve
Cochlear nerve
Limbic 2
Functions of Limbic system
Memory Emotions-related
responses
Limbic 3
Limbic system Amygdaloid body (amygdala) Hippocampal formation Hippocampus Parahippocampal gyrus Dentate gyrus
Septal area / Basal forebrain
Hypothalamus (Limbic) cortex: Cingulate
gyrus, Orbital (Orbiotfrontal) cortex, Prefrontal cortex, Insula
Anterior thalamus
Limbic 4
Amygdaloid Body (Amygdala, AMG) Position: between anterior end of temporal horn of
the lateral ventricle and the ventral surface of lentiform nucleus
Limbic 5
Olfactory nerve
Limbic
Temporal lobe
Olfactory nerve
6 Olfactory pathway
Olfactory nerve
Temporal lobe
Olfactory nerve Olfactory nerve
Temporal lobe
Olfactory nerve
Limbic 7
Olfactory pathway and AMG
Amygdala (AMG)
Limbic 8
AMYGDALA: division / nuclei Dorsal (corticomedial nuclei) Ventrolateral (central nuclei / basolateral nuclei)
Limbic 9
Dorsal (Corticomedial, Cortical) nuclei of AMG blending with uncus with afferents from olfactory bulb
(lateral olfactory area)
Olfactory bulb and cortex
Hypothalamus
AMG (Corticomedial)
Limbic 10
Ventrolateral (central and basolateral nuclei) of AMG
Both nuclei are a part of limbic system. Central nuclei: with corticomedial nu Basolateral nuclei: reciprocal connections with limbic cortex (prefrontal, temporal lobes and
cingulate gyrus); thalamus and brainstem: medio-dorsal (dorsomedial)
nuclei of thalamus, catecholamine nu, raphe nu, parabrachial nu of reticular formation;
septal area and anterior hypothalamus (stria terminalis)
Limbic 11
Interconnections of AMG
Cortex temporal, insular,
prefrontal, occipital
VentroLat-AMG
Thalamus (Medio-dorsal) Hypothalamus Brainstem
Sensory: somatic, visceral, auditory etc
AMG-Co Co-AMG
CM-AMG
Limbic 12
Major pathways for amygdala
Stria terminalis To and from brainstem
for regulations of autonomic responses etc.
Ventral amygdalofugal pathways via Diagonal band of Broca
Medial forebrain bundle
Afferent to AMG
Efferent to AMG
Limbic 13
Stria terminalis: septal area --- AMG
Fornix
Limbic 14
Stria terminalis
Th
Limbic 15 Stria terminalis
Limbic 16
Ventral amygdalofugal pathway (1)
Limbic 17
Ventral amygdalofugal pathway (2)
Emotionally driven activities also with some afferents
Amygdala Hippocampus Limbic cortex
Ventral striatum Ventral pallidum
Thalamus Dorsomedial nu.
Hypothalamus Brainstem
Limbic 18
Diagonal band of Broca in anterior perforated substance (orbital cortex,
behind olfactory tract, with passage of vessels) connections between amygdala and septal area
Limbic 19
Medial forebrain bundle
a collective term for fibers passing the ventral (basal) surface of the brain contains heterogeneous fiber tracts for
different destinations important tracts for ascending and descending
interconnections between septal area, hypothalamus and brainstem
Limbic 20
Median forebrain bundle
Limbic 21
Medial forebrain bundle
Limbic 22
AMG and autonomic nervous system AMG
Septal area / Anterior hypothalamus
Interpeduncular nu. of midbrain
Hypothalamospinal fibers
Habenular nu. of dorsal thalamus
Stria terminalis
Stria medullaris (thalami)
Fasciculus retroflexus
Dorsal longitudinal fasciculus
Limbic 23 Stria medullaris (thalami)
Limbic 24 Stria Medullaris Thalami
Limbic 25
Limbic 26
Functions of Amygdala
Related to emotional feelings Fear Anger
Methods of study Electrical stimulation Functional magnetic resonance imaging (fMRI) Destructive lesions in temporal lobes Kluver-Bucy Syndrome: docility, loss of ability
to learn, and abnormal sexual activity
Limbic 27
Olfactory system and Amygdala
Limbic 28
Fear perception and response
Visual perception Amygdala Neocortex: fear sensations / recognition Autonomic system: (unconscious) responses Conditional reflex, Memory
Limbic 29
Limbic 30
Summary: amygdala Organization corticomedial (olfactory) ventrolateral (limbic)
Connections cortex (limbic: prefrontal, temporal, cingulate) thalamus (medio-dorsal)/brainstem
(catechoaminergic) other limbic structures: septal area, hypothalmus
Pathways Stria terminalis Medial forebrain bundle Ventral amygdalofugal pathway
Limbic 31
Hippocampus Medial (mesial) surface of temporal lobe Anterior-posterior extension
Limbic 32
Hippocampus
Medial surface of temporal lobe
Beneath lateral ventricle
Limbic 33
Hippocampus
Limbic 34
Structure of hippocampus
Dentate gyrus Hippocampus
(proper), cornu ammonis
Parahippocampus gyrus Subiculum
Dentate gyrus
Hippocampus
uncus
Subiculum
Limbic 35
Hippocampus: Alveus
Myelinated axons (leaving & entering hippocampus) on ventricular surfaces of hippocampus; Forming the fimbria of hippocampus continuous with crus of fornix
Hippocampus
Limbic 37
Organization of Hippocampus: 3 layers
Molecular layer Pyramidal cell layer Polymorphic layer parahippocampal
gyrus: neocortex, with 6 layers
Limbic 38
Organization of Hippocampus: CA 1-3 CA (Cornus ammonis); CA1: Sommer’s sector
Limbic 39
Molecular layer of Hippocampus
with axons and dendrites continuous with molecular layers of dentate gyrus and
neocortex
Limbic 40
Pyramidal cell layer of Hippocampus
Large neurons: pyramidal cells
Principal cells of hippocampus;
With dendrites into Molecular layer;
Axons through alveus & fimbria to fornix
Limbic 41
Schaffer collateral
Schaffer collaterals: branches of axons of pyramidal cells;
passing polymorphic and pyramidal cell layers to synapse with dendrites of other pyramidal neurons
Limbic 42
Pyramidal cell layer of hippocampus
pyramidal neurons of CA1: sensitive to oxygen deprivation Temporal sclerosis Alzheimer disease
continuous with layer 5 (internal pyramidal) of neocortex
Limbic 43
Polymorphic cell layer of hippocampus
Beneath alveus, With axons,
dendrites and interneurons;
Equivalent to layer 6 of neocortex
Limbic 44
Organization of Dentate gyrus: 3 layers
Molecular layer Granule cell layer:
principal cells Polymorphic layer: Polymorphic
layer of dentate gyrus: contineous with that of CA3
Limbic 45
Efferent fibers of Dentate gyrus
Mossy fibers Traveling in hilus &
polymorphic layer; giving branches to synapse with pyramidal cells of CA2 and CA3
Roles for memory: long-term potentiation
Limbic 46
Hippocampus: Intrinsic connections
Limbic 47
Long-Term Potentiation (LTP)
present in Schaffer collaterals and mossy fibers of hippocampus
increase in synaptic efficiency following high-frequency activity of a pre-synaptic terminals
as molecular and cellular mechanism nderlying long-term memory
Limbic 48
Afferents to Hippocampus
Limbic 49
Entorhinal afferents
The largest afferents of hippocampal formation Perforant path Alvear path
• Entorhinal area: a part of lateral olfactory area and a gate for other cortical areas; receiving association fibers of temporal lobe and other neocortex
Limbic 50
Alvear path through subcortical
white matter and alveus to end in hippocampus
• Fornix and fimbria afferents: from contralateral hippocampus, from septal areas, basal forebrain cholinergic neurons (substantia inominata)
Limbic 51
Perforant path
axons from entorhinal area through subiculum & base of hippocampus to end in dentate gyrus
Limbic 52
Hippocampal efferents
Limbic 53
Fornix: the largest hippocampal efferents Origin: hippocampus &
parahippocampal gyrus Fimbria Crus: posterior limit of
hippocampus Body: in contact of
splenium (dorsal hippocampal commissure)
Column: above the 3rd ventricle; in front of interventricular foramen
Limbic 54
Column of Fornix pre-commisural protion of
fornix: above anterior commissure; giving fibers to septal area, anterior hypothalamus, substantia inominata
post-commissural portion of fornix: fibers to lateral dorsal thalamic nuclei, hypothalamus (mamillary body via mammilothalamic fasciculus to ant. nu of Th, ventromedial nucleus)
Limbic 55
Fornix
Limbic 56
Fornix
Limbic 57
Limbic 58
Mammillothalamic fasciculus (MTf)
Origin: mamillary body Terminals: anterior
nuclei of thalamus Anterior and lateral
dorsal thalamic nucleus having reciprocal communications with cingulate gyrus, which also has reciprocal communication with parahippocampus gyrus Mam. Body
Th.
Cingulum
Parahippo.
MTf
Limbic 59
Mamillo-thalamic fasciculus
Limbic 60
Mamillo-thalamic (Mamillothalamic) fasciculus / tract
Damaged in Korsakoff syndrome (alcoholic dementia) Amenesia Confabulation Apathy Lack of insight
http://www.youtube.com/watch?v=wDcyBXJAZNM http://www.youtube.com/watch?v=UbSlLtsJfUY
Limbic 61
Hippocampal function & dysfunction: memory and memory disorders
Types of memory Explicit (Declarative) memory: knowledge mainly verbal, language, mathematic contents etc
Implicit memory: learned skills, procedures, emotions associated structures: cerebellum, basal ganglia etc
Limbic 62
Declarative Memory
Steps of memory Immediate recall; Recent memory Memory consolidation; Long-term memory Information retrieving Factors: enhancing, interfering, emotional etc
Role of hippocampus in memory Retention of short-term memory and its Transfer to
long-term declarative memory
Limbic 63
Hippocampus and Memory: Cellular mechanism
Long-term potentiation (LTP) a postulated mechanism for
storage of recent memory requiring for permanent
memory new protein synthesis new synapse formation
Limbic 64
Role of hippocampus in learning “learning and memory”: impaired in mice with defective
functions of neurotransmitters in hippocampus
Limbic 65
Clinical Note of Hippocampus: Alzheimer disease Pathophysiology: cholinergic
hypothesis loss of cholinergic neurons
in basal forebrain projecting to limbic system (particularly hippocampus)
degeneration in entorhinal cortex, and hippocampus
Essential role of hippocampus: bilateral hippocampal lesions lead to memory loss, particularly recent memory
Limbic 66
The story of H.M.
Intractable seizure Temporal lobectomy,
partial Consequences Seizure: under control Blunt emotions Loss of memory
Limbic 67
H.M.
Limbic 68
What happens to H.M.? (How to improve memory for exam? 臨陣磨槍!)
RAM Disk
Hippocampus Cortex
Memory consolidation / Information retrieval
(macro)
Limbic 69
Case history 住台北的一位退休公務員 3/13:上午與太太搭高鐵南下高雄,中午參加一位老朋友的喪禮,晚上到台南,夜宿嫁到台南的女兒家。
3/14:清晨醒來,問:為什麼在這裡?對於昨天 (3/13)參加喪禮的事,一概否認,不記得有到高雄參加喪禮的事。一整天,一直 “ㄏㄨㄟ” 個不停。
3/15:早上離開台南,中午回到台北,一切恢復正常,但對於 3/12 晚間開始到 3/14 之間的事,完全沒有記憶。
What is your diagnosis ? 中邪?
Limbic 70
Transient Global Amnesia (TGA) a transient loss of memory, mainly recent events
with Normal intellectual functions Intact (1) immediate recall and (2) remote memory
Duration: usually resolve within 24 h Etiology and mechanisms: unknown, with transient
lesions (mainly vascular insufficiency) in the hippocampus
Limbic 71
Transient global amnesia
Limbic 72
Cortex
Entorhinal cortex
Subiculum CA3 Dentate gyrus
Perforant pathway
Hippocampus and Cerebral cortex
CA1 Mossy fibers
Schaffer collaterals
Limbic 73
睡醒後就失憶: 她,天天重新做人 (2010.06.12 自由時報) 〔編譯羅彥傑/綜合報導〕英國一名四十七歲的已
婚婦女,因兩次車禍導致腦部受損,喪失自從一九九四年以來的短期記憶,此後每天醒來都是同一天,也讓丈夫每天都得說服她相信兩人是夫妻,頗類似好萊塢愛情喜劇「50 First Dates (我的失憶女友)」劇情。
英國《每日郵報》十一日報導說,住在英格蘭林肯郡斯波耳丁市的米歇兒.菲波茲每天一覺醒來,枕邊人都得說服她,兩人是夫妻。當她表現懷疑時,菲波茲先生就去拿相簿,給她看兩人在一九九七年(十三年前)的結婚照。
米 歇兒在一九八五年與一九九○年先後發生機車與汽車車禍,造成腦部受損。她的記憶最遠可追溯到一九九四年,但此後任何一天發生的事情,隔天就全忘光。這種情 況令人聯想到二○○四年電影「我的失憶女友」,劇中男主角亞當山德勒嘗試追求女主角茱兒芭莉摩,但後者在車禍後就喪失每天日常生活的記憶。
Limbic 74
睡醒後就失憶: 她,天天重新做人 (2010.06.12 自由時報)
米歇兒得使用數以百計的便利貼及手機日曆的記事提醒功能,幫助自己記得每天的行程與要做的事。她做過的事或見過的人,都必須記錄下來,以便日後參考用。當她偶爾離家出外遊玩時,還必須攜帶輸入住家地址的衛星導航系統。
劍橋大學神經科學家耐斯特說,米歇兒罹患的是罕見的順向失憶症(或前行性失憶症)。不過,這對她也有一些好處,譬如沒有電視節目重播的困擾,每一則笑話也都很好笑,因為每次都是第一次聽到。她目前擔任慈善團體志工,每週有三天照顧殘障人士。
Limbic 75
Review: Hippocampus Organization Hippocampus Dentate gyrus
Synaptic pathways Schaffer collaterals Mossy fibers
Major afferents and efferents Alvear path Perforant path Fornix