Amygdaloid Body and Temporal Lobe
Rahul's Noteblog
Notes on Neurology
Subcortical Grey Matter
Amygdaloid Body and Temporal Lobe
Amygdaloid Body and Temporal Lobe
Amygdala functions:
• Behavioral and emotional function.
• Fear, irritability, anger.
• Furious defensive reaction and aggressive noises and gestures and sympathetic +++.
• Damage in man also affects hippocampus and visual association cortex of the temporal lobe mixture of behavioral and cognitive disturbances.
Temporal lobe epilepsy:
• Anxiety states (inappropriate activity of amygdala).
• Depression.
• Schizophrenia.
Temporal Lobe Destruction:
Monkey: Bilateral temporal lobe excision.
Kluver-Bucy Syndrome.
• Docility.
• Lack of emotional responses (i.e. fear or anger).
• Increased, inappropriate sexual activity / drive.
• Unable to perform tricks or tasks (unable to do new learning).
• Lack of recognition of objects; compensates by exploring objects with its mouth. This is termed visual agnosia or psychic blindness = loss of visual association cortex for formed images. Associated with excessive eating.
Amygdaloid Complex**:
• Gray mass in temporal lobe.
• 2-3 nuclei (two main nuclear massas).
• Afferent fibres: olfactory, diencephalon, hypothalamus.
• Peptides: somatostatin, ENK, SP, CCK, NT, VIP.
• Projections to cerebral cortex (F, ins, T, O, somatosensory), basal ganglia.
• Function: "olfactory," higher cognitive and motivational function, behavior, defence reaction, fear, confusion, disturbance of awareness, amnesia. Removal placcidity, decrease in aggression and assaultive behavior, no emotional excitability, normalise social behavior; integrator of autonomic and visceral functions.
**Essential for correlation of emotional expression and meaningful behavior.
Amygdalar Function:
• Modulates hypothalamus (due to vast connections).
• Damage: - hypothalamus (aphagia or hyperphagia).
• Subjective feelings.
• Emotions (fear: pupils, adrenalin, HR).
• Damage: Lack of aggression; tame, placid.
• Memory deficit.
Anatomy of Memory*:
• Posterior temporal lobes (long term memory storage).
• Hippocampus (+ parahippocampal areas).
• Rhinal cortex* (entorhinal) profound amnesia.
• Diencephalon (anterior, dorsomedial nuclei and mammillary bodies1 of the hypothalamus? Thalamus? Amygdala).
• Recognition and declarative memory short- and long memory.
• Korsakoff's syndrome (ante- and retrograde).
Anatomy of Memory 2:
Hippocampus*
• Spatial memory (going down a maze).
• Working memory or relational memory.
• Temporal lobe: declarative and procedural memory.
* Working memory resides in multiple brain locations especially prefrontal cortex (= problem solving; planning behavior).
Anatomy of Memory 3:
Types of Memory and Amnesia:
• Learning.
• Declarative memory.
• Procedural memory.
• Short-term memory.
• Long-term memory.
• Consolidation.
• Working memory.
• Retrograde amnesia.
• Anterograde amnesia.
• Transient global amnesia.
Further Topics on Subcortical Grey Matter:
1. Notes on Thalamus
2. Notes on Pineal Gland
3. Notes on Hypothalamus
4. Notes on Limbic System
5. Notes on Pituitary Gland
6. Notes on Basal Nuclei
7. Amygdaloid Body and Temporal Lobe
Additional Reading:
Basic Neurology
1. Peripheral Nervous System
2. Central Nervous System
3. The Ventricular System
4. The Spinal Cord
5. The Brain Stem
6. The Cerebellum
7. Visual Pathways
8. Diencephalon
9. Basal Ganglia
10. Cerebral Cortex
11. Sleep Disorders
12. Autonomic Nervous System
13. Cranial Nerves and Parasympathetic Ganglia
14. Cells of the Nervous System
15. Cerebrospinal fluid
16. Additional short notes on Cerebrum
17. Functions and Diseases of Cerebrum
18. Subcortical Grey Matter
19. Notes on The Spinal Cord
20. Regulation of Heart Rate by Autonomic Nervous System
21. Action Potentials, Axon Conduction, and Neuromuscular Junction
22. Types of Seizures
23. What is a Cough Reflex?
24. Notes on Congenital Prosopagnosia
25. Findings in Parkinson's Disease
26. Types of Heat Strokes
27. Types of Strokes
28. What is Benign Intracranial Hypertension?
29. What is Cauda Equina Syndrome?
30. Cranial Nerve Locations in Brain Stem
31. What is a Cluster Headache?
32. What is a Subarachnoid Hemorrhage?
33. What is a Tension Headache?
Neurology Videos
1. Video of Neurology Examination in a Clinical Setting
Medical Images
Useful Medical Images & Diagrams (link opens in a new window)
Related Topics
1. Nervous System Disorders
2. Histology of Nervous Tissue
3. Cranial Nerve Reflexes
4. Motor System Examination
Random Pages:
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