Diencephalon Neuroscience I PDF

Diencephalon Neuroscience I Acknowledgement to Corrine Boyea and Ron Objectives Identify key structures of the diencephalon Describe the role of the thalamus in sensory processing Differentiate functions of the various structures of the dienceph...

Diencephalon Neuroscience I Acknowledgement to Corrine Boyea and Ron Objectives Identify key structures of the diencephalon Describe the role of the thalamus in sensory processing Differentiate functions of the various structures of the diencephalon Compare and contrast normal vs. abnormal function of the brain in relation to structure location Anatomy of the Central Nervous System Cortex Thalamus Hypothala mus Epithalamu s Diencephalon Definitions (simplified…) Thalamus: Relay center for information destined to reach the cerebral cortex Hypothalamus: Regulates pituitary gland to form link between neural and endocrine systems Epithalamus: Group of nuclei, including pineal gland which modulates circadian rhythms and influences secretions of other endocrine structures Subthalamus: Group of nuclei and associated white matter including the subthalmic nucleus, which functions as part of the basal ganglia External Anatomy of the Central Nervous System cerebral hemisphere cauda rostral cerebellum pons medulla whole brain – lateral view Image design credit Dr. Bon spinal cord External Anatomy of the Central Nervous System cerebrum Cerebrum = Cerebral hemispheres + diencephalon diencephalon midbrain midbrain cerebellum cerebellum brainstem brainstem pons pons medulla medulla hemisected brain – sagittal view spinal spinal cord cord Image design credit Dr. Bon Diencephalon 1.thalamus 1.thalamus Thalamus: relay center for information destined to reach the cerebral cortex hypothalamic hypothalamic sulcus sulcus 3. 3. epithalamus epithalamus 2. 2. hypothalamus hypothalamus 4. 4. subthalamus subthalamus –– not not shown shown hemisected brain – sagittal view Image design credit Dr. Bon  Diencephalon thalamic thalamic nuclei nuclei thalamus diencephalon midbrain pons rontal/coronal section of the cerebrum Image design credit Dr. Bon  Diencephalon Thalamus Subthalamic Nucleus Frontal/coronal section of the cerebrum Blumenfeld Diencephalon thalamus thalamus cor pus call osu m x rni fo interthalamic interthalamic adhesion adhesion (massa (massa intermedia) intermedia) hypothalamic hypothalamic sulcus sulcus hypothalamus hypothalamus midbrain epithalamus epithalamus Image design credit Dr. Bon Thalamus Relay center for information destined to reach the cerebral cortex Inputs: basal ganglia, cerebellum, sensory systems (except olfactory), limbic system, reticular formation Output: cerebral cortex Functions: Processes information Selective filter for cerebral cortex Directs attention to important info, regulates flow of info to cortex Regulates activity level of cortical neurons Lundy-Ekman Thalamus Relay station for sensory Primary information somatosensory cortex Thalam us arm li W u m sti Blumenfeld Thalamus Relay center for sensory and non-sensory information Reciprocal connections Moto r Memory, Emotions Moto Arousa r l Sensory Blumenfeld Thalamus Blumenfe  Thalamic nuclei can (Input) (Output) be classified into VA (Basal ganglia) three main VL (Cerebellar nuclei) VP functional groups: Convey info from sensory systems Rela L VPM (except olfactory), the basal y ganglia or cerebellum to cerebral Nucl MG N cortex ei LG N Process emotional and memory Associati info or integrate different types on Nuclei of sensations Nonspeci Regulate consciousness, arousal, attention fic Nuclei Lundy-Ekman Lundy-Ekman. DO NOT MEMORIZE (unless nuclei Thalamic Lesions* Deficits in contralateral sensation Thalamic pain syndrome Disordered consciousness Pusher syndrome: Impaired sense of vertical https://somepomed.org/articulos/contents/mobipreview.htm?5/47/5877 Hypothalamus Regulates pituitary gland to form link between neural and endocrine systems Efferent neural connections with cortex (via thalamus), emotion system, brainstem and spinal cord Functions: Maintaining homeostasis Eating, reproductive, and defensive behaviors Emotional expression Regulation of circadian (daily) rhythms Endocrine regulation of growth, metabolism, and reproductive organs Activation of the sympathetic nervous system Lundy-Ekman, Blumenfeld Hypothalamus and Pituitary Gland Helps control hormones by regulating secretions of the pituitary gland Lundy-Ekman Hypothalamus Blumenfeld Hypothalamus thalamus thalamus corp u s ca llos u m ix rn fo hypothalamus hypothalamus midbrain epithalamus epithalamus optic optic chiasm chiasm pituitary (infundibulum) pituitary stalk (infundibulum) stalk Image design credit Dr. Bon Hypothalamus hypothalamic nuclei pituitary gland hypothalamus hypothalamus pituitary pituitary stalk stalk (infundibulum) (infundibulum) hemisected brain – sagittal view Image design credit Dr. Bon Epithalamus and Subthalamus EPITHALAMUS SUBTHALAMUS Posterior segment of Location: superior to diencephalon substantia nigra of Pineal gland: helps midbrain regulate circadian rhythm, Contains subthalamic influences secretions of nucleus pituitary gland, adrenals, Functions as part of the parathyroids, islet of basal ganglia circuit, helps langerhans regulate movement  Diencephalon Subthalamic Nucleus Frontal/coronal section of the cerebrum Blumenfeld Diencephalon thalamus thalamus cor pus call osu m x rni fo interthalamic interthalamic adhesion adhesion (massa (massa intermedia) intermedia) hypothalamic hypothalamic sulcus sulcus hypothalamus hypothalamus midbrain epithalamus epithalamus Image design credit Dr. Bon References Course notes, Dr. Ron Bond and Corrine Boyea Lundy-Ekman L. Neuroscience: Fundamentals for rehabilitation. St. Louis, Mo: Saunders/Elsevier; 2007. Blumenfeld H. Neuroanatomy Through Clinical Cases. Sunderland, Mass.: Sinauer Associates; 2010.