Limbic & emotions 18 april 2016

1. Limbic system and
physiology of emotions
Dr Madanmohan. MD, DSc, FIA
Prof. & Head, Department of Physiology
Mahatma Gandhi Medical College & research
Institute

2. Limbus: border, ring.
Rim of cortical tissue around hilum
and associated subcortical structures.
Emotion: a strong feeling

4. Limbic
system

5. Learning objectives
1. Draw a schematic diagram of limbic system and
label its components.
2. Name areas of brain that are functionally
connected to limbic system via afferents and
efferents.
3. Draw schematic diagram of Papez circuit and
describe its significance.
4. Define the terms: emotion, instinct, behavior,
motivation.
5. State the functions of lymbic system.
6. Briefly describe the nature of emotions.

6. Limbic system
• Visceral brain /rhinencephalon
• Medial aspect, on top of neuraxis
• Advanced part of primitive brain

7. Allocortex: primitive brain, phylogenetically oldest
3 layers. Hippocampus.
Juxtallocortex: transitional, 3-6 layers.
Cingulate, insula.
Neocortex: highest developed, 6 layers.
Phylogenetically newest

8. Limbic
system

9. Limbic: components
Limbic cortex/lobe:
Orbito-frontal cortex.
Insular area.
Cingulate gyrus.
Hippocampal gyrus.
Uncus.
Parts of parietal
and temporal lobes.
Related areas:
Hypothalamus.
Ant. thalamus.
Midbrain RF.
Frontal cortex.
Amygdala.
Septal nucleus.

10. Limbic: connections
1. Intrinsic
2. Neocortex
3. Olfactory area
4. Thalamus (somatic)
5. Hypothalamus (visceral)
6. Midbrain RF
Papez circuit

11. Papez circuit
Prefrontal cortex
Cingulate gyrus
Ant. thal Hypothal
Mam. body

12. Functions
1. Integrates afferent impulses:
olfactory, visceral, somatic.
2. Emotions: lesion/stimulation:
rage, placidity, fearlessness.
3.Motivation: reward/punishment areas.
4. Feeding behavior: survival of individual.
.
5. Sexual behavior & mating: survival of species.

13. 6. Endocrine functions
7. Recent memory
8. Circadian rhythms
9. Preservation of self and species

14. Instinct: innate behavior pattern
playing, eating, mating, parenting.
Motivation: to stimulate/inspire to action,
incentive.
Behavior: the way we conduct ourselves.
Emotion: the way we feel. A strong feeling.

15. Emotions: components
1. Cognition: awareness of sensation.
2. Affect: feeling.
3. Conation: urge to act.
4. Physiological
responses: BP, fh, GSR……..

16. Negative emotions: anger, rage, grief, fear,
lust, greed, jealousy, ego.
Positive emotions: love, compassion,
human values.
Replace negative emotions by positive ones *

17. Emotions: neurophysiological correlates
Rage & fighting: lateral hypothalamus.
Tranquility: ventromedial hypothalamus.
Sex drive: anterior & most posterior hypothal.
Reward area: median fore brain bundle.
Punishment area: central grey around aqueduct
of Sylvius.

18. Limbic system & emotions: applied
Stimulation experiments: amygdala: anger/rage.
Aggressive patients: amygdaloidectomy.
Damage : encephalitis (influenza), tumor,
brain or pituitary surgery.
Gonadal hormones : aggressive behavior.
Sex steroids in uterus.
Uncontrolled emotions : destructive
Suppressed emotions : stress

19. Emotional disorders:
We have needs & desires.
Expectations too.
Can neocortex “satisfy” limbic needs ?
Cortex is above limbic system.
Mind-body interactions & civilized behavior.

20. Emotional and / or rational?
• Can we change our emotions and behavior?
• Can neocortex (prefrontal lobe) control basic,
limbic, animal behavior?

21. Emotions, morbidity and mortality:
new perspectives from
psychoneuroimmunology
Kiecolt-Glaser et al. Ann Rev Psychol 2002; 53: 83-
107

23. Yoga for drug abuse
Benson H. N Engl J Med 1969; 281: 1133

24. Nature Nurture
(genes) (practice)
24