1. PhD MD MBBS Faculty of Medicine Al Maarefa Colleges of Science & Technology Faculty of Medicine Al Maarefa Colleges of Science & Technology Lecture – 11: Limbic System Nervous System Physiology By Dr. SHAHAB SHAIKH PhD MD MBBS Faculty of Medicine Al Maarefa Colleges of Science & Technology Faculty of Medicine Al Maarefa Colleges of Science & Technology

2. LIMBIC SYSTEM basis of learn and memory Limbic System includes a complex set of brain structures located on both sides of the thalamus, at the base of cerebrum: موجودة حتى بالبيس اوف سكل 2

3. LIMBIC SYSTEM The limbic system operates by influencing the endocrine system and the autonomic nervous system. Functions: –Emotion –Motivation –Behavior –Decision Making –Pleasure Center (Nucleus Accumbens) –Associated with Learning & Memory 3

4. Emotions: what is emotion? Basic sensation, harmful or beneficial to decide what to do whit it 4 LIMBIC SYSTEM

5. Cingulate Gyrus Situated in the medial aspect of the cerebral cortex and lies immediately above the corpus callosum. is involved with emotion formation and processing, learning and memory. important role in disorders such as depression and schizophrenia. **** Work as associated center 5

6. Amygdala: remember func Are two almond-shaped groups of nuclei located deep and medially within the temporal lobes of the brain. Perform a primary role in the processing of memory, decision-making, and emotional reactions. There are functional differences between the right and left amygdala and also between Male and Female Amygdala. Tremendous lobe in personality, on shy person will be small, and will differ from left to right … 6

7. Amygdala : remember role in fear 7 The Amygdala perform primary role in the formation and storage of memories associated with emotional events. E.g. Fear Conditioning. Also involved in emotional memory consolidation - Formation of Long Term Memory. The amygdala plays a pivotal role in triggering a state of fear. Amygdala is associated with Anxiety and panic attacks. Studies link amygdalae to the emotional reactions of PTSD patients. : post-traumatic stress disorder

8. Amygdala Role in Social behavior: It is hypothesized that larger amygdalae allow for greater emotional intelligence, enabling greater societal integration and cooperation with others. –Many friends more larger amygdala Stimulating the amygdala appears to increase both sexual and aggressive behavior. 8

9. Amygdala 9 Bilateral damage of amygdala results in- Happens to Arteficaly cutting removal of temporal lobe, as treating for eplipsy (Klüwer-Bucy Syndrome): Not afraid of anything Extreme curiosity about everything Forgets rapidly Tendency to place everything in mouth & eating objects Strong sexual drive Aggressive

10. Hippocampus Major part of limbic system located in the medial temporal lobe of the brain bilaterally. Has important role in formation of new memory about experienced events (Episodic Memory). Bilateral hippocampal damage results: short memory for 2-3 mins, then will forget mainly in Anterograde: before accident will remember, but after accident no new memory will be formed amnesia and often also retrograde amnesia= past memory Believed to have role in spatial memory and navigation. 10

11. Hippocampus 11 Hippocampal sclerosis is the most commonly visible type of tissue damage in temporal lobe epilepsy In Alzheimer's disease and any amnesia, the hippocampus is one of the first regions of the brain to suffer damage. There is evidence that there is atrophy of the hippocampus more than of other parts of the brain in humans having post-traumatic stress disorder, has role in schizophrenia or severe depression.

12. Limbic Cortex Cerebral association area for limbic system functions for control of behavior 12

13. lateral hypothalamus – eating, thirst, general level of activity, rage ventromedial nucleus – satiety, tranquility periventricular nucleus – fear, punishment reactions anterior and posterior hypothalamus – sexual drive Behavioral Functions of the Hypothalamus

14. Behavior and its Control Remember their other location other than of limbic system Reward center located in ( remember) the lateral and ventromedial hypothalamus, thalamus certain areas, Amygdala Punishment center located in Hypothalamus Thalamus Amygdala and Hippocampus

15. Neurotransmitters associated with limbic system Norepinephrine Dopamine Serotonin 15

16. Clinical Application Dementia Alzheimer disease Amnesias Anxiety Depression etc. Neurosis : fell it’s wrong or psychosis : not knowing it’s wrong 16