Download LIMBIC SYSTEM

Central Nervous System
Limbic System
边缘系统
Introduction
Case
A 40-year-old woman awoke from sleep and complained to her
husband of an indescribable unpleasant odor, nausea, and a
panicky, fearful sensation. During the following week, she had
repeated stereotyped episodes of this kind followed by decreased
responsiveness and slow, inappropriate speech lasting 2 to 3
minutes.
As we shall see, limbic system abnormalities can cause
paroxysmal disorders as seen in this patient. In this chapter we will
learn about this important and diverse neural system and the
consequences of limbic system damage or dysfunction.
History
Paul Broca (1824-1880): a French
physician, surgeon,anatomist, and
anthropologist. He is best known for
his research on Broca's area, a region
of the frontal lobe that has been
named after him.
The term “le grand lobe limbique”
（边缘叶）was first used by Broca
in 1878.
James Papez (1883-1958):
an American neuroanatomist
He is most famous for his
1937 description of the Papez
circuit which is a neural
pathway in the brain thought
to be involved in the cortical
control of emotion.
Papez Circuit (Emotions)
Fornix
Mammillary bodies
Other hypothalamic nuclei
Septal nuclei
Substantia innominata
(Basal nucleus of Meynert)
Hippocampal Formation
(hippocampus
and dentate gyrus)
Parahippocampal Gyrus
Neocortex
Mammillothalamic
tract
Anterior Thalamic
nuclear group
Cortex of Cingulate Gyrus
Paul D. MacLean (1913-2007)
an American physician and
neuroscientist who made
significant contributions in the
fields of physiology, psychiatry,
and brain research.
The term ‘limbic system’ was first
used by MacLean in 1952 to
describe a set of structurally and
functionally related structures of
the brain bordering the midline,
inner surface of each cerebral
hemisphere.
What are the limbic system ?
The LIMBIC SYSTEM includes diverse cortical and
subcortical structures located mainly in the medial and ventral
regions of the cerebral hemispheres. These structures are
unified by their evolutionarily ancient origins, and they
constitute the major portion of the forebrain in many species.
Only in higher mammals has the larger neocortical mantle
surpassed the limbic system in size.
Anatomy of limbic system
Main components of the LIMBIC SYSTEM

Core component: Hippocampus and amygdala.
海马与杏仁核

Cortex: Cingulated ，parahipocampal gyrus and prefrontal cortex.
扣带回、海马旁回与前额叶皮质

Nuclei: Hippocampus , septal nuclei 隔核 , amygdala,
Anterior and dorsomedial thalamus (丘脑前核和背内侧核),
Hypothalamus- mammillary body (下丘脑-乳头体）,
Ventromedial hypothalamus （下丘脑腹内侧部）.
The main circuit of Limbic System
What are the main functions of Limbic System?
The functions of the limbic system are also ancient, and they play an
important role for survival in the animal kingdom. Limbic functions
can be divided into the following four basic categories:
1. Homeostatic functions 稳态,
including autonomic and neuroendocrine control
2. Olfaction 嗅觉
3. Memory 记忆
4. Emotions and drives
“HOME”
The other important functions of limbic System

Generates emotions (Emotional brain)

Add feeling to sensory experience which direct to
behavior.

Affect: interpret the sensory experience as pleasant or
unpleasant.

Memory and learning which is closely linked to emotion.

Sexual behavior, emotions of rage ,fear, anxiety and
motivation
Part 1. Amygdaloid body
• Amygdaloid body :
Large nuclear group in temporal lobe.
Regions of the Amygdala

Large basolateral region: 基底外侧核
Provides direct input to basal ganglia and
motor system.

Small corticomedial group of nuclei: 皮质内侧核
Related to olfactory cortex.

Central nuclei: 中央核
Connected to hypothalamus.
Amygdala Connections
Cerebral cortex
Olfactory system
Thalamus
Brainstem reticular formation
Stria
terminalis
Hypothalamus
AMYGDALA
Ventral Amygdalofugal fibers
杏仁核腹侧通路
Amygdala Inputs
Olfactory
System
Temporal Lobe
(associated with visual,
auditory, tactile senses)
AMYGDALA
Corticomedial Nuclear
Group
Basolateral Nuclear
Group
Central Nucleus
Brainstem (viscerosensory relay
Nuclei: solitary nucleus
and parabrachial nucleus)
Ventral
Amygdalofugal
Fibers
Amygdala Outputs
Stria Terminalis
Septal Nuclei
Hypothalamus
AMYGDALA
Corticomedial Nuclear
Group
Dorsal Medial Thalamic Nucleus
Nucleus Accumbens
Hypothalamus
Basolateral Nuclear
Group
Central Nucleus
Nuclei of
ANS
Ventral
Amygdalofugal
Fibers
Ventral
Amygdalofugal
Fibers
Functions of the Amygdala
Relate environmental stimuli to
coordinated behavioral autonomic and
endocrine responses seen in speciespreservation.
 Responses include:

Feeding and drinking
Agnostic (fighting) behavior
Mating and maternal care
Responses to physical or emotional stresses.
Part 2. Hippocampus
Greek: “Sea Monster”
Hippocampus

Any sensory stimulus will go to the hippocampus, and from
there to the thalamus, hypothalamus and other limbic
structures through FORNIX 穹窿.

Stimulation of hippocampus can cause pleasure, rage, sex
drive, etc.

Important feature of hippocampus is that it creates
prolonged response

It has only three layered cortex.

It has role in learning and memory
Gross Anatomy and location
From Digital Anatomist
“C” shaped structure in medial temporal lobe
Morphology

Another terminology mess
 Allocortex/ archicortex 古皮质
 Hippocampal formation 海马结构
 Dentate gyrus 齿状回
 Hippocampus 海马
“Cornu ammonis” 阿蒙氏角
 Subicular complex 下托
 Entorhinal cortex 内嗅皮质
Hippocampus
1- hippocampal body
2 – head and digitationes hippocampi
3 – hippocampal tail
4 – fimbria (fornix) 海马伞
5 – fornix 穹隆
6 – subiculum 下托
Neocortex greatest developed in human
Hippocampus of Rat
Development of Hippocampus
From Digital Anatomist
From Digital Anatomist
Cytoarchitecture
Two interlocking cell fields
• Dentate gyrus
• hippocampus
Human
Rodent
so sp
•Stratum oriens 始层
•Stratum pyramidale 锥体层
•Stratum lucidum 透明层
•Stratum radiatum 辐射层
•Stratum lacunosummoleculare 网状分子层
sl
sr
sl-m
ml
Hilus
CA1-CA3: pyramidal neurons
Dentate Gyrus: granule cells
Intrinsic connections
苔藓纤维通路
谢弗侧支通路
Cajal, 1901
hippocampal Network: The hippocampus forms a principally uni-directional network,
with input from the Entorhinal Cortex (EC) that forms connections with the Dentate
Gyrus (DG) and CA3 pyramidal neurons via the Perforant Path (PP). CA3 neurons
also receive input from the DG via the Mossy Fibres (MF). They send axons to CA1
pyramidal cells via the Schaffer Collateral Pathway (SC), as well as to CA1 cells in the
contralateral hippocampus via the Associational Commisural (AC) Pathway. CA1
neurons also receive inputs direct from the Perforant Path and send axons to the
Subiculum (Sb). These neurons in turn send the main hippocampal output back to
the EC, forming a loop.
Connections
Afferents:
 Much of cortex is reciprocally
connected to entorhinal cortex
内嗅皮质
 Cholinergic and GABA input
via septal nuclei 隔核
 Amygdala
 VTA 中脑腹侧被盖区, LC蓝斑,
Raphe n. 中缝核
Efferents
 Via the fornix 穹隆
 Precommissural: septal nuclei
 Post-commisural: mammillary
bodies (to anterior thalamic
nucleus via mammillothalamic
tract)
Two limbic Axis








Hippocampal
Extroceptive 外感受
Cognitive processeslearning and memory 认知
Receive information from
cortical sensory areas
Project to ant. Thalamus
Ant. Thalamus-cingulate
gyrus-hippocampus (Papez
circuit)
Hippocampus-mammillary
body-thalamus
Project to basal ganglion
Project to mid brain via
medial forebrain bundle.








Amygdaloid
Introceptive内感受
Generation of emotions,
motivational states 情感，动机
Cortical sensory areas and
internal organs
Dorso medial thalamus
Dorso medial thalamusprefrontal cortex-amygdala.
Amygdala –ventro medial
hypothalamus
Project to basal ganglion.
Project to mid brain via
medial forebrain bundle.
Part 3. Hypothalamus
Limbic system and hypothalamus
Hypothalamus 下丘脑
Embryological Development of the Anterior and Posterior Pituitary
Peptidergic neuroendocrine cells:
Magnocellular neurons

“Large” neurons

Located in paraventricular and supraoptic nuclei

Secrete oxytocin and vasopressin into general
circulation via posterior pituitary

Oxytocin

Vasopressin
uterine contraction & milk ejection
vasoconstriction, water
resorption by the kidney
Peptidergic neuroendocrine cells:
Parvocellular neurons

“small” neurons

Located in medial basal region, arcuate and tuberal
nuclei, periventricular region, preoptic and
paraventricular nuclei

Secrete releasing and inhibiting hormones into portal
vasculature via anterior pituitary

Nobel prize awarded to Guillemin (Salk), Schally and
Yalow in 1977 for their (independent) work in proving the
hypothesis that the hypothalamus releases hormones
that regulate the pituitary
Portal veins of hypophysis
Hypothalamus pathways
Afferent Pathway
Projecting from
Median forebrain bundle
Collaterals from other tracts
Fornix
Hippocampus (to MB)
Stria terminalis
amygdala
Efferent Pathway
Projecting to
hypothalamicohypophyseal
(from supraoptic nuclei)
Mammillothalamic tract
Neurohypophysis (pituitary)
Anterior thalamic nucleus
Widespread projections to many brain regions, including the
cerebral cortex, via histamine and hypocretin containing
neurons in the tuberal region of the hypothalamus
Part 4. Cingulate gyus and
Parahippocampal gyrus
思考题

简述边缘系统的研究历史

边缘系统包括哪些结构？核心结构是什么？

试述杏仁核的位置、核团分部、纤维联系及功能。

试述海马的位置、分区、细胞构筑、内部通路及
外部纤维联系。

试述下丘脑的位置及其与神经内分泌的关系。
Thanks !