thalamus latest , physiology and illustrated

thalamus

1. THALAMUS

2. Anterior VA VL VPL VPM LD LP Pulvinar LGN MGN DM Functional Connections Mammillary Body Cingulate Gyrus Amygdala Hypothalamus Olfactory Cortex Prefrontal Cortex Globus Pallidus Substantia Nigra Premotor Cortex Prefrontal Cortex GP SN Cerebellum (Dentate) Primary Motor Cortex (4) Supplementary Motor Cortex (5_ Cingulate Superior Parietal Cortex (5,7) Spinothalamic and LL/ML Sensory Cortex (3,1,2) , Solitary Nucleus Sensory Cortex Right Optic Tract Primary visual Cortex (17) (lingual gyrus, cuneus) Brachium of Inferior Colliculus Primary Auditory Cortex (41,42) LGN, Superior Colliculus Association areas of temporal, occipital, parietal lobes Lesion: memory loss (Wernicke-Korsakoff) Lesion: Sensory Aphasia Lesion: contralateral loss of pain/temp, discrim touch Lesion: contralateral loss of pain/temp, discrim touch in head; ipsilateral loss of taste Lesion: Left Homonymous Hemianopsia

3. 3 Dr. Mohammad Adnan Khalil Thalamic Nuclei & their Relays in 3D

4. CLASSIFICATION OF THALAMIC NUCLEI A. NON- SPECIFIC PROJECTION NUCLEI: MIDLINE CENTRO-MEDIAN Afferent : RAS, basal ganglia Efferent : striatum and neo-cortex

5. CLASSIFICATION OF THALAMIC NUCLEI B. SPECIFIC PROJECTION NUCLEI: SPECIFIC SENSORY RELAY 1. MEDIAL GENICULATE BODY Afferent : topically organised projection fibres of auditory fibres from cochlear nerve, lateral lemniscus inferior colliculus Efferent : Auditory area 41,42

6. CLASSIFICATION OF THALAMIC NUCLEI 2. LATERAL GENICULATE BODY Afferent : RETINA Efferent : Area 17,18,19 3. VENTRAL POSTERIO- LATERAL NUCLEI Afferent : Medial Lemniscus (whole body except face) Efferent : area 3,1,2 4. VENTRAL POSTERIO- MEDIAL: Afferent : Trigeminal Lemniscus Efferent : area 3,1,2

7. CLASSIFICATION OF THALAMIC NUCLEI B. SPECIFIC PROJECTION NUCLEI: MOTOR CONTROL NUCLEI: 1. VENTRO LATERAL Afferent : Dentato - thalamic Efferent : area 4,6 2. VENTRAL ANTERIOR : Afferent : Globus pallidus , subs. N. , Cerebellum Efferent: premotor - 6

8. CLASSIFICATION OF THALAMIC NUCLEI C: VISCERAL EFFERENT CONTROL 1. ANTERIOR NUCEUS (PAPEZ CIRCUIT) Afferent : Hippocampus via fornix and relayed through mamillary body Efferent : Cingulate gyrus ( 24) 2. DORSAL MEDIAL NUCLEUS: Prefrontal and hypothalamus – thinking ,memory judgment, emotional behavior

9. CLASSIFICATION OF THALAMIC NUCLEI D: INTEGRATIVE AND PERCEPTUAL FUNCTION CONTROL NUCLEI 1. PULVINAR Afferent : Visual , auditory and other sensations Superior and inferior colliculus Efferent : Parietal, occipital and superior temporal ( auditory and visual association areas)

10. CLASSIFICATION OF THALAMIC NUCLEI D: INTEGRATIVE AND PERCEPTUAL FUNCTION CONTROL NUCLEI 2. LATERAL POSTERIOR : afferent : sup. Colliculus efferent : sup. Parietal lobe ---cingulate parahippocampal area 3. DORSAL LATERAL : afferent : superior colliculus efferent : cingulate gyrus , parahippocampal gyrus , parietal lobe

11. FUNCTIONS 1 . SENSORY RELAY CENTRE 2. CENTRE FOR INTEGRATION OF SENSORY IMPULSE ( processing of sensory information and functional gateway to cortex) 3. CRUDE CENTRE FOR PERCEPTION OF SENSATION : e.g.pain ( discrimination is by cortex but affective nature i.e. capacity to determine whether pleasant or unpleasant is by thalamus )

12. FUNCTIONS 4. CENTRE FOR INTEGRATION OF MOTOR FUNCTIONS: (from basal ganglia and cerebellum output comes to thalamus before projecting to cortex ) 5. ROLE OF AROUSAL AND ALERTNESS REACTION ( by non- specific projection impulses from RAS , are relayed to cortex via thalamus) 6. ROLE IN EMOTIONAL ASPECT OF BEHAVIOUR

13. FUNCTIONS 7. ROLE IN LANGUAGE : Integration between different cortical parts by subcortical connections 8. ROLE IN SYNCHRONIZATION OF EEG 9. CENTRE FOR INTEGRATION OF VISCERAL AND SOMATIC FUNCTION 10 . CENTRE FOR SEXUAL SENSATION 11. CENTRE FOR REFLEX ACTIVITY

14. NUCLEUS FUNCTIONS VPM Relay station for impulses from face, head & taste buds VPL Relay Station for exteroceptive & proprioceptive from all body EXCEPT head & face VA Relay station for Striatal impulses (attention & recent memory ) VL (VI) Relay station for cerebellar impulses MGB Relay station for Auditory impulses LGB Relay station for Visual(Optic) impulses

15. NUCLEUS FUNCTIONS Anterior Attention & recent Memory Medial dorsal Associated with mood & emotional balance Lateral Dorsal Integrates Sensory information Lateral Posterior Integrates Sensory information Pulvinar Correlates auditory & visual information with sensations

16. NUCLEUS FUNCTIONS Reticular Forms part of ascending reticular activating system Intralaminar (Including centromedian ) Awareness of painful stimuli at thalamic level