referenced

1. By:- Hina Khalid

3.  Introduction of limbic system
 Anatomy, physiology of limbic
system
 Structures of Limbic system
 Functions of structures
 Related prblems

4.  The term "limbic" comes from the Latin limbus,
for "border" or "edge.
 The set of brain structures that forms the inner
border of the cortex.
 System is the area of the brain that regulates
emotion and memory.
 It includes many structures in the cerebral pre-
cortex and sub-cortex of the brain .
 The term has been used within psychiatry and
neurology.

5.  The definition of the limbic system is still evolving.
 Broca,s (1878) “limbic lobe” was primarily cortical.
 The Kluver-Bucy syndrome (1937-1939): Bi-lateral
temporal lobectomy in monkeys produced: visual
agnosias (“psychic blindness”:cannot recognize the
meaning of objects),oral tendencies
 compulsion to react to every visual stimulus, changes
in emotional behavior, in dietary habits, and in sexual
behavior.

6.  Upon histology, they found that the lesion
involved temporal association cortex, the
amygdala, the hippocampus, and the fornix
(connects the hippocampus to the septal
nucleus and hypothalamus).

8.  was delineated by James Papez,The Papez circuit
consists of
 Hippocampus
 Fornix
 mamillary bodies
 anterior nucleus of the thalamus
 cingulate gyrus.
 boundaries of the limbic system were subsequently
expanded to include the amygdala, septum, basal
forebrain, nucleus accumbens, and orbitofrontal
cortex.

9. Amygdale; almond shaped mass of nuclei involved in
emotional responses, hormonal secretions, and
memory.
 Cingulate gyrus; a fold in the brain involved with
sensory input concerning emotions and the
regulation of aggressive behavior.
 Fornix; an arching, fibrous band of nerve fibers that
connect the hippocampus to the hypothalamus.
 Hippocampus; a tiny nub that acts as a memory
indexer -- sending memories out to the appropriate
part of the cerebral hemisphere for long-term
storage and retrieving them.

10.  Plasticity and Attention
 Responding to stress
 Learning about emotional stimuli
 learning, or classical conditioning
 Affective state
 Memory
 Feelings of pleasure that are related to our survival,
such as those experienced from eating and sex
 New memories(damage to this area of the brain may
result in an inability to form new memories)

11. •The Amygdala is important for
making associations across stimulus
modalities (a certain fragrance often
elicits an associated visual image).
It appears to be responsible for the
influence of emotional states on
sensory inputs.
•This produces a spectrum of sensory
perceptions from apparently identical
stimuli
(ex. the sound of one's own
motorcycle is never perceived as
noise). Thought to be responsible for
face recognition.

13.  The amygdala involved in many cognitive
processes.
 Just like in the hippocampus, memory seems to
be impacted by processes in the amygdale;
however, it is not spatial memory like the
hippocampus, but episodic-autobiographical
memory (EAM) networks.
 The amygdala, as researched by Markowitsch
was found to be responsible for the encoding,
storage, and retrieval of these types of
memories.

14.  Besides memory, the amygdala also seems to be
an important brain region involved in
socialization fear attention and emotional
processes.
 Pessoa generalized this concept with help from
evidence of EEG recordings, and concluded that
the amygdala helps an organism to define a
stimulus and therefore respond accordingly the
amygdala was initially thought to be linked to
fear, this gave way for research in the amygdala
for emotional processes, anxiety disorders.

15.  The Cingulate (to surround) Gyrus (fold), is part of
the cerebrum gray matter surrounding and directly
connected to the parts of the inner Limbic System.
The Cingulate Gyrus serves as a conduit of messages
to and from the inner Limbic System.

17.  An arching, fibrous band of nerve fibers that
connect the hippocampus to the hypothalamus.
 The hypothalamus sits under the thalamus at the
top of the brainstem. Although the hypothalamus is
small, it controls many critical bodily functions:
 Controls autonomic nervous system Center for
emotional response and behavior Regulates body
temperature Regulates food intake Regulates water
balance and thirst Controls sleep-wake cycles
Controls endocrine system

18.  The Hippocampus is very important in the transition of
information from short to long term memory
 It is also part of the Temporal Lobe, damage to that
portion of the brain can result in a loss of memory.
 The size of a pearl, this structure directs a multitude of
important functions. It wakes you up in the morning,
and gets the adrenaline flowing.
 The hypothalamus is also an important emotional
center, controlling the molecules that make you feel
exhilarated, angry, or unhappy.

19.  The mammillary bodies (mamillary bodies) are a pair of
small round bodies, located on the undersurface of
the brain, that, as part of the diencephalon form part of
the limbic system. They are located at the ends of
the anterior arches of the fornix. They consist of two
groups of nuclei, the medial mammillary nuclei and the
lateral mammillary nuclei . Neuroanatomists have often
categorized the mammillary bodies as part of
the hypothalamus
FunctionsThey, along with the anterior and dorsomedial
nuclei in the thalamus, are involved with the processing
of recognition memory.
 They are believed to add the element of smell to memories.

21.  The hypothalamus is shaded blue. The pituitary
gland extends from the hypothalamus.
 It is also part of the Temporal Lobe, damage to that
portion of the brain can result in a loss of memory.
 The size of a pearl, this structure directs a multitude
of important functions. It wakes you up in the
morning, and gets the adrenaline flowing.
 The hypothalamus is also an important emotional
center, controlling the molecules that make you feel
exhilarated, angry, or unhappy.

22.  The Hippocampus is very important in the transition of
information from short to long term memory
 It is also part of the Temporal Lobe, damage to that portion of
the brain can result in a loss of memory.
 The size of a pearl, this structure directs a multitude of
important functions. It wakes you up in the morning, and
gets the adrenaline flowing.
 The hypothalamus is also an important emotional center,
controlling the molecules that make you feel exhilarated,
angry, or unhappy.

23.  It has been demonstrated to be involved in various
processes of cognition. The first and most widely
researched area concerns memory, spatial memory
in particular.
 Spatial memory was found to have many sub-
regions in the hippocampus, such as the dental
gyrus (DG) in the dorsal hippocampus, the left
hippocampus, and the Para hippocampus region.
 The dorsal hippocampus was found to be an
important component for the generation of new
neurons, called adult-born granules (GC).

24.  Over the decades, has also been found to have a
huge impact in learning.
 Hippocampus damage
 Damage relayed to the hippocampus region of
the brain has reported vast effects on overall
cognitive functioning, particularly memory such
as spatial memory.
 Researchers particularly investigated the effects
that high emotional arousal and certain types of
drugs had on the recall ability in this specific
memory type.

25.  Lines the walls of 3rd
ventricle, above the
pituitary.
 Divided into medial
and lateral regions
by the fornix, bundles
of fiber tracts that
connect the
hippocampus to the
mamillary bodies.

26.  The hypothalamus is a grouping of nuclei that lie
along the base of the brain near the pituitary gland.
 The hypothalamus connects with many other regions
of the brain and is responsible for controlling
hunger, thirst, emotions, body temperature
regulation, and circadian rhythms The
hypothalamus also controls the pituitary gland by
secreting hormones, which gives the hypothalamus a
great deal of control over many body functions.

27.  A major function of the nervous system is to
maintain homeostasis, or the stability of the
internal environment.
 The hypothalamus, which comprises less than
1% of the total volume of the brain, is intimately
connected to a number of structures within the
limbic system and brainstem.
 Together the hypothalamus and the limbic
system exert control on the endocrine system
the autonomic nervous system to maintain
homeostasis.

28.  Emotions and motivated behavior are crucial for
survival:
 Emotional responses modulate the autonomic nervous
system to respond to threatening stimuli or situations.
 Emotional responses are adaptive. If you are prepared to
deal with threatening stimuli, you are more likely to
survive and reproduce.
 Motivated behavior underlies feeding, sexual and other
behaviors integral to promoting survival and reproduction.

29. Fever ; Need to detect temperature changes and
modulate the autonomic nervous system to either
retain or dissipate heat.
Addiction ; Many recreational drugs work through
neural pathways involved in reward and motivated
behavior that form an important part of limbic system
function.
Anxiety Disorders; Many anxiety disorders, such as
Panic Disorder and Post-traumatic stress disorder
have physiological symptoms mediated by the
autonomic nervous system and by the limbic system.
Obesity ; Feeding behavior is in part controlled by the
hypothalamus, and interactions between limbic
reward circuitry and the hypothalamus are important
to feeding behavior.

30.  The structures of higher olfactory processing in
phylogenetically more primitive animals have
evolved in humans into the limbic system, the center
of the emotional brain and the gate through which
experience is admitted into memory according to
emotional significance.

32.  Alzheimer's changes the whole brain
 Alzheimer's disease leads to nerve cell death and
tissue loss throughout the brain. Over time, the brain
shrinks dramatically, affecting nearly all its functions.

33.  In the Alzheimer's brain:
 The cortex shrivels up, damaging areas
involved in thinking, planning and
remembering.
 Shrinkage is especially severe in
the hippocampus, an area of the cortex that
plays a key role in formation of new memories.
 Ventricles (fluid-filled spaces within the brain)
grow larger

35.  Alzheimer's tissue has many fewer nerve cells
and synapses than a healthy brain
 Plaques, abnormal clusters of protein
fragments, build up between nerve cells.
 Dead and dying nerve cells
contain tangles, which are made up of twisted
strands of another protein.

36.  The hypothalamus just above the brain stem,
acts as an integrator for autonomic functions,
receiving ANS regulatory input from the limbic
system to do so.

38.  Amnesia patients have trouble retaining long
term memories.
 Difficulty creating recent term lost of memories
is called intergraded amnesia and is caused by
damage to the hippocampus part of the brain
which is a major part of the memory process.
 Retrograde amnesia is also caused by damage to
the hippocampus but the memories that were
encoded or in the process of being encoded in
long term memory are erased.

39.  The limbic system has been particularly
implicated in neuropathological studies of
schizophrenia.
 Several clinicopathological studies have found a
reduction in the brain weight of the gray matter
but not of the white matter in persons with
schizophrenia.
 In pathological as well as in magnetic resonance
imaging (MRI) reports, persons with
schizophrenia may have reduced volume of the
hippocampus, amygdala, and parahippocampal
gyrus.

40.  During the hallucinations, the same cortical and
subcortical structures were activated as were
activated by the actual sounds, including the
primary auditory cortex. At the same time,
decreased activation was seen of areas thought to
monitor speech, including the left middle temporal
gyrus and the supplementary motor area.
 Neuropathological studies have shown a decreased
density of neuropils, the intertwined axons and
dendrites of the neurons, in the frontal lobes of these
patients.

48.  Tucker, D. M., Derryberry, D., & Luu, P. (2000).
Anatomy and Physiology of Human Emotion:
Vertical Integration of Brainstem, Limbic, and
Cortical Systems. In J. Borod (Ed.),
Handbook of the Neuropsychology of Emotion. New
York: Oxford.
 Wada G Webb.,Richard K .Adler(4th
edition)
(2008)NEUROLOGY for the Speech-Language
Pathology.