LIMBIC SYSTEM

1. LIMBIC SYSTEM kaan yücel m.d.,ph.d.

2. Outline IntroductiontotheLimbicSystem 2. History of theLimbicSystem 3. Main Players of theLimbicSystem 4. FunctionalAnatomy of theLimbicSystem LimbicSystemDysfunction 5.1. Anatomy of majordepressivedisorder 5.2. Anatomy of someneuropsychiatricdisorders

3. IntroductionTothe Limbic System

4. 1.1. What does limbus mean?

6. 1.1. What does limbus mean? Limbo Lat. BorderEdgeCircle Ring

7. 1.2. What is limbicsystem? • survival YOUR MISSION IN LIFE?

8. Two main functions Emotionalprocessing Motivation TheAnatomy of Behaviour

9. Emotion Memory MedialTemporalLobe • Hippocampus • Parahippocampalgyrus • Amygdala

10. The limbic system works to process our emotions and is related to motivation and with its connections with the cognitive partsof the brain helps us to “use our mind” a.k.a. accomplish mental processes.

11. The limbic system structures are telencephalic& subcortical structures. • The complex network for the process of emotions and is also related to memory and learning in addition to hippocampus, amygdala and parahippocampusincludes: • Cingulate gyrus • Hypothalamus • Major areas in the prefrontal cortex • Striatum • Somethalamicnuclei • Orbitofrontal cortex • Septal area • Some medial components of the midbrain (e.g. VTA) • Habenula… • + whitemattertracts

13. 2. HISTORY OF the Limbic System

16. AnterogradeamnesIA H.M. Henry Gustav Molaison (1926–2008) Dr. William Beecher Scoville EPILEPSY Treatment Bilateralremoval of medialtemporallobe hippocampus, amygdala & parahippocampalgyrus

17. Names Phone numbers SHORT- TERM MEMORY

18. Great Limbic Lobe Le Grand Lobe Limbique Pierre Paul Broca Cingulategyrus (L. cingulated=belt) & parahippocampalgyrus form a ring on the medial surface of the mammalian brain.

20. James Papez PapezCircuit Alist of structures in the brain and a closed circuit related to emotions

21. Hippocampal formation (Subiculum) → fornix → mammillary bodies Mammillary bodies → mammillothalamic tract → anterior thalamic nucleus Anterior thalamic nucleus → genu of the internal capsule → cingulate gyrus Cingulate gyrus → cingulum → parahippocampalgyrus Parahippocampalgyrus → entorhinal cortex → perforant pathway → hippocampus.

24. LimbicSystem • added • Amygdala • Septum • Pre-frontal cortex • to the Papez circuit Paul D. MacLean

26. Klüver-Bucy Syndrome bilateral removal of amygdala and hippocampal formation What happens if we remove the medial temporal lobe of an animal, a monkey? • Becamedocile;”good monkeys”. • A tendency towards oral behaviour such as attempting to ingest inedible objects. • Hypersexualizedbehaviour by mounting females of the same and different species. • Acompulsion to attend and react to every visual stimulus • No fear. • Changein dietary habits

28. 1848 The patient Phineas Gage 1919 Pneumoencephalography was first introduced. 1936 First “frontal lobotomy” operation was performed on a Kansas housewife. 1958 Nautaadded midbrain structures in the limbic system, such as habenula 1967Freeman operated his last frontal lobotomy and after that this operation was banned.

29. 1974Ingvar and Franzen first reported frontal lobe hypoperfusion using Single Photon Emission Computed Tomography (SPECT) in a series of chronic schizophrenic patients. 1974 Siemens Medical Solutions (then known as Siemens Medical Engineering) presented the first commercially available computed tomography system. 1975 Ventral striatum concept defined by Heimer 1977 Limbic striatum concept defined by Nauta and Domesick 1977First MRI scan in history was accomplished.

30. 1982 "Cortical atrophy in schizophrenia and mania: a comparative CT study” published in Journal of Clinical Psychiatry by Nasrallah and his colleagues. 1983“Ventricular enlargement in child psychiatric patients: a controlled study with planimetric measurements” published in American Journal of Psychiatry by Reiss and his colleagues. 1988 The article of Robert Sapolsky from Stanford University titled as “Glucocorticoid toxicity in the hippocampus: in vitro demonstration” published in the journal Brain Research.

31. 1992“Anatomic basis of amygdaloid and hippocampal volume measurement by magnetic resonance imaging” published in the journal “Neurology” by Craig Watson and his colleagues. 1994“Functional magnetic resonance imaging at 1.5 T: activation pattern in schizophrenic patients receiving neuroleptic medication.” published in the journal”Magnetic Resonance Imaging” by Wenz and his colleagues.

32. 3. MAIN PLAYERS OF the Limbic System

33. the most famous two guys of the limbic system hippocampus &amygdala

34. 3.1. Hippocampal formation/Hippocampus Temporalhorn of lateralventricle HC

36. TERMINOLOGY HIPPOCAMPAL FORMATION VS. HIPPOCAMPUS 1. Hippocampus(proper) CornuAmmonis (CA) CA1-CA4 2. Dentategyrus 3. Subicularcomplex

38. Fornix [Arch] Theroad/whitemattertractfromthehippocampus Precommissural fibers 25% Septal area Postcommmissural fibersoriginatefromthesubicularcomplex Mamillarybodies

39. Fornix

41. 3.2. Amygdaloid complex/Amygdala

45. Twomain pathways emerging from the amygdala Striaterminalis terminate in the septal area, the medial preoptic area of the hypothalamus, and the bed nucleus of striaterminalis Ventralamygdalahypothalamictract (Ventralamygdalofugalpathway) main projection pathway from the amygdala to the hypothalamus

46. 3.3. Parahippocampalgyrus

47. 3.4. Cingulate gyrus

48. 3.4.1. Anterior cingulate cortex (ACC) 1=BA25 (subcallosalgyrus) 2=BA24sg (SGPFC) 3=BA32 (paracingulategyrus)

49. 3.4.2. Posterior cingulate cortex (PCC) Right CingulateCortex Subgenualprefrontalcortex (SGPFC) Rostral ACC Caudal ACC PCC RöthlisbergerM, Riecher-Rössler A, Aston J, Fusar-Poli P, Radü EW, Borgwardt S. Cingulate volume abnormalities in emerging psychosis.Curr Pharm Des. 2012;18:495-504.