Love you guys with my whole Limbic system... Limbic System from where the main feelings comes... Here we go.. It got the main structures seen here along with some other related areas... CONNECTIONS (Papez circuit simplified) Different functions of Limbic system... Fear vs. Rage, sham rage, reward and punisment, hippocampus and memory related functions... Some applied aspects are also covered... THANK YOU

1. LIMBIC SYSTEM

2. Here’s the truth: People,
even regular people, are
never just any one
person with one set of
attributes. It’s not that
simple. We’re all at the
mercy of the limbic
system, clouds of
electricity drifting through
the brain.
INDRANI SAHA
DARAKSHA SAJID KHAN
FARHAJ SULTANA
MANDAKINI DHURIA
SANTONA KHATUN
Jonathan Nolan
British-American screenwriter, television
producer, director and author

3. The word limbus means
ring, the term limbic
system is applied to the
parts of the cortical and
subcortical structures
that form a ring around
the upper end of the
brainstem.
Phylogenetically, limbic
cortex is the oldest part of
the cerebral cortex.

4. HYPOTHALAMIC
NUCLEI
AMYGDALA
MAIN STRUCTURES SEEN HERE…

5. OTHER RELATED AREAS…
Septum Pellucidum
Indusium Griseum
Corpus
Callosum
Anterior
commissure
Subcallosal
area
Paraterminal
gyrus
Fornix
Amygdala Parahippocampal
gyrus
Mamillary
body
Fimbria
Hippocampus
Limbic Gyrus Intralimbic Gyrus Fornix & Inner arc

6. CONNECTIONS:
• Cortical and subcortical structures form close circuit
connections enabling limbic system to activate
practically whole CNS.
• Neocortex also influences the limbic system to some
extent , so it is no longer considered as “A HORSE
WITHOUT THE RIDER”.
• Among circuits , the most famous one is ‘Papez
Circuit’.

7. PAPEZ CIRCUIT:
• It has role in emotion.
• Cingulate gyrus receives inputs from various parts via
anterior thalamus.
• Cingulate gyrus projects to hippocampus.
• Hippocampus sends efferent to hypothalamus, directly
or via amygdala.
• Hypothalamus has close connection with multiple
autonomic, involuntary functions of body , which are
common accompaniments of emotion.
• Hypothalamus sends efferent to anterior thalamus and
this reinforces the emotional response in a positive
feedback fashion.

9. LIMBIC FUNCTIONS:
Stimulation and ablation experiments
indicate functions,
• Bilateral ablation of amygdala in kluver –Bucy animal
 abnormal placidity, fearlessness, hypersexuality.
• Lesions of amygdala  abolish fear as it is a part of
allocortex. It fulfils primitive need of food and sex.
• Limbic stimulation along with hypothalamus  rage,
emotion, sexual behaviour , motivation.
• Autonomic functions, eg. Blood pressure, respiration.

10.  FEAR Vs. RAGE:
• FEAR:-
 Characterized by tendency to avoid sweating,
dialation of pupils and animal tries to flee.
 It is also called “the fleeing /avoidance response”.
 Amygdaloid nuclei are concerned with encoding of
memories to evoke fear.

12. FEAR Vs RAGE:
• RAGE:-
Associated with hissing, spitting, snarling, pupil
dialation, contraction of arrectores pilorum.
Animal tries to attack the offender.
Also called ‘fighting reaction’.
 Fear and rage appear to be different in nature,
but fear in a fleeing animal is
converted to rage to protect itself.

13. SHAM RAGE
• It was called on erroneous belief that the rage
response in animals suffering from diencephalic
and forebrain damage is a purely ‘physical’
response without any emotional involvement.
• However it appears to be incorrect.
• Animals dislike rage response.
• It is a type of conditioned avoidance with
presence of unpleasant emotional feelings.

14.  KLUVER-BUCY ANIMAL:-
• Associated with bilateral temporal lobectomy (including
amygdala) that results in KLUVER-BUCY SYNDROME
• In monkeys, the features are 
1. Remarkable docility.
2. Excessive sexual urge, often mounting animals of same
sex.
3. Visual agrosia.
4. Forgetfulness.
5. Compulsive tendency to examine things orally.
6. Increased attention to all stimuli.
7. Fearlessness, even picking up and eating snakes which
they are afraid of normally.

15. HIPPOCAMPUS AND MEMORY
• During an experience many different areas
of neocortex are activated.
• When we remember the experience similar
areas are activated.
• Hippocampus acts as an index, storing
different patterns of neocortex activity.
• It converts short term memory to long term
memory.

16. REWARD AND PUNISHMENT
• The 'reward areas' in the brain
include ventral tegmentum and
nucleus accumbens and the
dopaminergic pathway connecting
them.
• The lateral part of posterior
hypothalamus,dorsal part of
midbrain and entorhinal cortex
form the 'punishment areas.'
• Motivation in an animal is brought
about by stimulation of the reward
system.
• Drug addiction is based on the fact
that opiates,alcohol and nicotine
raise the concentration of
dopamine acting on D3 receptors.
• They exert their addictive action
through the reward system.

17. HOW THE BRAIN FALLS IN
LOVE
1.The Ventral Tegmental Area
releases dopamine,thus,activating
the reward circuit.
2.Serotonin levels decrease which
results in obsession and
infatuation.
3.Oxytocin and vasopressin,
released from the pituitary gland,
lead to feelings of connection.
4.The amygdala gets deactivated
which leads to deactivation of
fear and social judgment.
5.The person in love feels less
stress and fear and more content
and calm.

18. PSYCHOSIS
4% of the world population
suffers from psychotic
disorders.
Signs and symptoms
Delusions
Hallucinations
Agitation/Aggression
Alogia(poverty of speech)
Avolition(loss of
motivation)
Decrease in social
abilities

19. Causes include disorders in:
MESOCORTICAL PATHWAY which connects the Ventral Tegmental
Area to the Prefrontal Cortex.
MESOLIMBIC PATHWAY which connects the Ventral Tegmental
Area to the Nucleus Accumbens.

20. • The Ventral Tegmental Area
neurons are dopaminergic.
• In psychosis following
changes occur:
• In the mesolimbic pathway
dopamine release and
binding to D2 receptors
increases.
• In the mesocortical
pathway dopamine release
and binding to D1 receptors
decreases.
• Treatment is done by using
antipsychotic drugs like D2
antagonists.

21. SCHIZOPHRENIA
• The Papez Circuit is involved in schizophrenia.
• Decreased size of hippocampus.
• Decreased activity in the prefrontal cortex.

22. MAJOR DEPRESSIVE
DISORDER
 Monoamine deficiency:
Decrease in serotonin,
norepinephrine and dopamine
levels.

23. ALZHEIMER'S DISEASE
• Amyloid plaques build
up outside cells and
neurofibrillary tangles
inside cells,leading to
neuronal death.
• Hippocampus and
cortex degenerate
leading to amnesia and
dementia.

24. EPILEPSY:
Hippocampal sclerosis is seen along with involvement of amygdala
and parahippocampal gyrus.
Reduced number of GABAergic cells with glutamatergic excitotoxicity.
AUTISM:
Impairment of cognitive and affective processing.
The cingulate gyrus and amygdala are involved which mediate
cognitive processing.

25. Limbic system
Conclusion

27. THANK YOU