BIPN 160 - FINAL EXAM

#separator:tab #html:true What are the key areas for motor control?motor cortex, basal ganglia, spinal cord, & cerebellum Definition of motor unit 1 motor neuron & all the muscle fibers it innervates Describe slow fibersslow, consistent, low force Describe fast resistant fibersfast, consistent, strong force Describe fast fatigable fibersfastest, transient, strongest force Order of motor unit recruitmentslow twitch > fast resistant > fast fatigue What does recruitment of muscle fibers do?Increases force Describe the activity in motor areas during planning and execution of movement<ul><li>Planning - SMA/PMd/IPS areas active</li><li>Execution - M1 active</li></ul> Describe projection of motor cortical areas<ul><li>PMd/SMA project to M1</li><li>PMd/SMA/M1 all project to striatum, brainstem, and spinal cord</li></ul> Parts of the striatumcaudate nucleus & putamen Parts of the basal gangliaGP & STN Roles of the basal ganglia in movement<div>BGIEOS - But Gary, I eat only snails</div><ul><li>Initiation of movement</li><li>Execution of movement sequences</li><li>Opposing pathways to increase/decrease movement</li><li>Select one action & inhibit others</li></ul> Pathway for striatal cortical loop"Cortex → striatum/caudate → GP → thalamus → cortex" D1 action on thalamusnet excitation D2 action on thalamusnet inhibition Mechanism of D1Rsexcitation by activating AC Mechanism of D2Rsinhibition by suppressing AC Direct pathway in putamen"D1R stimulates direct pathway → putamen inhibits GPi/SNr → GPi/SNr inhibits thalamus → net excitation to allow movement <img src=""paste-d9a6afee1c04562e6f5054026f7d86a93d26942f.jpg"">" Indirect pathway in putamen"D2R stimulates indirect pathway → putamen inhibits GPe → GPe inhibits STN → STN excites GPi/SNr → GPi/SNr inhibits thalamus → net inhibition of movement <img src=""paste-d9a6afee1c04562e6f5054026f7d86a93d26942f.jpg"">" Describe dopaminergic input to the basal ganglia circuitDA activates D1Rs and inhibits D2Rs Function of basal ganglia to cortex loopsbody movements, eye movements, cognitive tasks, & emotional states Symptoms of striatum damage<ul><li>slowness of voluntary movement</li><li>involuntary movements and postures</li><li>Damage to both direct/indirect paths</li></ul> Symptoms of STN damage<ul><li>Large amplitude involuntary limb movements</li><li>Loss of indirect path</li></ul> Symptoms of GP damage<ul><li>Slowness of movement</li><li>Abnormal postures</li><li>Difficulty relaxing muscles</li><li>No delay in movement initiation though</li></ul> Describe Huntington's disease<ul><li>Genetic disorder that leads to neuronal death in the caudate & putamen nuclei of the striatum</li><li>Hyperkinetic abnormal, involuntary, and impaired movements</li></ul> Describe Parkinson's disease<ul><li>Degeneration of DA neurons in substantia nigra (SN)</li><li>Tremors & slowness of movements</li></ul> Describe OCD<ul><li>Complex disease</li><li>Damage to prefrontal striatal connections are associated with compulsive motor programs</li></ul> Describe Tourette's<ul><li>Associated with damage to all parts of basal ganglia-cortical loop</li><li>Uncontrolled tics or sudden movements/vocalizations</li></ul> Patern controller in motor control"Hypothalamus & thalamus <img src=""Tz8dv3W6IYrpL25N2KbyU8UO_hIKiZb3Xug3auWziO5RNrP4aP0lOCXSjyyMJdpmh090P-h_k-0-EWdNqwc6ELqYfFy9ms5VKYmIbOSMuER2VDtk5x4.png"">" Pattern initiator in motor control"midbrain & basal ganglia <img src=""Tz8dv3W6IYrpL25N2KbyU8UO_hIKiZb3Xug3auWziO5RNrP4aP0lOCXSjyyMJdpmh090P-h_k-0-EWdNqwc6ELqYfFy9ms5VKYmIbOSMuER2VDtk5x4.png"">" Pattern generator in motor control"Hindbrain & spinal cord <img src=""Tz8dv3W6IYrpL25N2KbyU8UO_hIKiZb3Xug3auWziO5RNrP4aP0lOCXSjyyMJdpmh090P-h_k-0-EWdNqwc6ELqYfFy9ms5VKYmIbOSMuER2VDtk5x4.png"">" Role of cerebral cortex in motor controlskilled movements Role of brainstem in motor controlposture & eye movements Role of spinal cord in motor controlspinal reflexes & locomotion Role of basal ganglia in motor controlinitiation of movement & pattern selection Role of cerebellum in motor controlmotor coordination & correction Describe the sensorimotor feedback system of the cerebellum<ul><li>Gets information about motor commands being sent from brain to muscle</li><li>Gets feedback information about muscle state & limb position</li><li>Fine-tune movements to correct for off-target effects or variation between planned & predicted movement</li></ul> Cerebellum makes up __% of brain volume but has __% of total neurons10; 80 Clinical symptoms of cerebellum damage<ul><li>Midline postural instability</li><li>Ataxia, uncoordinated movements, or stumbling</li><li>Slurred and/or scanning speech</li><li>Non-motor cognitive and emotional symptoms</li></ul> What is astasia-abasia<ul><li>Form of ataxia - inability to stand or walk</li><li>Due to loss of ability to maintain limb/body posture</li><li>Swaying gait</li></ul> What is dysmetria<ul><li>Inability to coordinate a complex motor activity involving several muscle groups</li><li>Cannot control distance/speed/ROM necessary to perform smoothly coordinated movements</li></ul> Activity in cerebellar areas before and during movement<ul><li>Lateral hemisphere = planning</li><li>Midline areas = during & after movement</li></ul> Inputs and outputs of cerebellar peduncles<ul><li>Superior = major outputs to thalamus</li><li>Middle = motor command inputs from pontine nucleus of motor cortex</li><li>Inferior = motor command input from spinal cord & brainstem</li></ul> Most of the outer part of the cerebellum is..."cerebellar cortex <img src=""M4-r8sKEvR0z_el_E4mIKmH4VsGxgkCV0gpA_jjY3I062n08u95QFWusXUI_O7AKDxj6tMhjEM8oi8bAwOmzw3yxxjhQwgFkHs9RhAKYud6ov8j1jJj.png"">" Most medial nucleus of cerebellum"fastigial <img src=""M4-r8sKEvR0z_el_E4mIKmH4VsGxgkCV0gpA_jjY3I062n08u95QFWusXUI_O7AKDxj6tMhjEM8oi8bAwOmzw3yxxjhQwgFkHs9RhAKYud6ov8j1jJj.png"">" Most lateral nucleus of cerebellum"dentate <img src=""M4-r8sKEvR0z_el_E4mIKmH4VsGxgkCV0gpA_jjY3I062n08u95QFWusXUI_O7AKDxj6tMhjEM8oi8bAwOmzw3yxxjhQwgFkHs9RhAKYud6ov8j1jJj.png"">" Where is the interposed nucleus located?"between fastigial & dentate <img src=""M4-r8sKEvR0z_el_E4mIKmH4VsGxgkCV0gpA_jjY3I062n08u95QFWusXUI_O7AKDxj6tMhjEM8oi8bAwOmzw3yxxjhQwgFkHs9RhAKYud6ov8j1jJj.png"">" Basic flow of information in cerebellum<ul><li>Cerebellar cortex receives excitatory inputs from other CNS areas</li><li>GABA-ergic Purkinje cells inhibit cerebellar nuclei</li><li>Cerebellar nuclei send excitatory outputs to other brain areas</li></ul> Projections of cerebellar cortex"<ul><li>Lateral hemisphere → dentate</li><li>Medial hemisphere → interposed</li><li>Vermis → fastigial </li></ul>" Inputs to the vermis come from...vestibular nuclei, motor cortex, & spinal cord (controls trunk of body) Inputs to the medial hemisphere of the cerebellum come from...Motor cortex & spinal cord (limb control) Inputs to the lateral hemisphere of the cerebellum come from...widespread cortical inputs Output of fastigial nucleusvestibular nuclei & brainstem Output of interposed nucleusThalamus, brainstem, & inferior olive Output of dentate nucleusthalamus Describe the layers of the cerebellum and what they contain (molecular, Purkinje, granule, white matter)"<ul><li>Molecular = dendrites of Purkinje cells</li><li>Purkinje cell layer = cell bodies of Purkinje cells</li><li>Granule cell layer = granule cells</li><li>White matter = where Purkinje cells synapse onto cerebellar nuclei</li></ul><div><img src=""cN4cZgFAZirqx2DsRpeXyFpV_8N4Jr1tWeiHyO29IT81jDt6BfGMd_5Q_Bj54NtXb61ukqHeqcsGzu5d0k3lc4QpHZzA0_K4RclnAFtuo5sVYQIHO8g.png""> </div>" Describe the folliam of the cerebellar cortex"<ul><li>Folliam = 1 fold of cortex</li><li>Granule layer is dense with cells, molecular layer is not dense</li></ul><div><img src=""irKtSLWb6_Yr5idOYyJgIQ1PmQaICnlXyjifgG9FePM_fmGtsoBCFBEDVFtJTfMr9thmhOr4cySXBtpb_ACRDG1QmLLCRVcC9g15mOd-qYI0y3RQgO2.png""> </div><div> </div>" Location of hippocampusLocated in medial temporal lobe, inferior to amygdala Hippocampal inputsEntorhinal cortex, amydala, & widespread cortical areas Neuromodulatory inputs to the hippocampus & functions<ul><li>NE from LC = attention</li><li>5HT from dorsal raphe = mood</li><li>DA from SN = movement</li><li>ACh from medial septum = novelty</li></ul> Outputs of hippocampusEntorhinal cortex, thalamus, hypothalamus, amygdala, widespread cortical areas What are declarative memories"factual information that you can consciously recall" What are non-declarative memories"procedural and unconscious memories" Trisynaptic circuit in hippocampusEntorhinal cortex projects to: <ul><li>Dentate gyrus</li><li>CA3 (mossy fiber)</li><li>CA1 (Schaffer collateral)</li></ul> What is an engram?memory trace that exists in a web of neurons, that are linked together during memory encoding and active during retrieval What is a place cell?neuron in hippocampus that fires in a specific location in space Describe the granularity of the PFC in primatesPFC is mostly granular, ACC is agranular in primates Describe the granularity of PFC in rodentsall agranular Frontotemporal dementiaNeurodegerative condition that leads to: <ul><li>impulsive behavior</li><li>disregard of social conventions</li><li>lack of sympathy</li></ul> Sociopathy<ul><li>antisocial behaviors</li><li>manipulations</li><li>deceit</li><li>high rate of PFC damage among violent criminals</li></ul> Traumatic brain injury<ul><li>caused by accidents and warfare</li><li>deficits in decision-making, planning, and impulsivity</li></ul> Inputs and outputs of PFC<ul><li>PFC gets widespread inputs from other cortical areas</li><li>Outputs to behavioral control centers (basal ganglia & motor areas)</li></ul> Regions and functions of PFC<ul><li>Dorsomedial (DMPFC) = attention & decision making</li><li>Anterior cingulate (ACC) = sense of self & empathy</li><li>Dorsolateral (DMPFC) = integration of information & working memory</li><li>Ventromedial (VMPFC) = impulse control</li><li>Orbitofrontal (OFC) = emotional valence</li></ul> What is fear extinction?"process of learning that a cue that previously predicted an aversive stimulus no longer predicts the aversive stimulus" How does the OFC override innate behaviors?"<ul><li>activating reward pathway to NAc</li><li>inhibiting aversive pathway to MeA</li></ul>" Crick & Koch definition of consciousness<ul><li>Requires working memory and attention</li><li>Unified perception distinct from specific sensory features</li><li>Binds together different sensory features, must result from neurons that have input from all sensory modalities</li></ul> Location & anatomy of claustrum<ul><li>Sits @ midline between frontal and temporal lobes</li><li>Band of gray matter that is highly connected with other brain areas (sensory cortex, PFC, amygdala, etc)</li><li>Most interconnected brain area</li></ul> What is the role of the claustrum in distraction?The claustrum supports resilience to distraction Meningeal layersDura, arachnoid, pia How do the meninges divide the brain?separates the two hemispheres Dura materthick collagenous tissue that adheres to the skull Arachnoid materthin layer partially attached to dura/pia Pia materthin layer attached to the brain What does the dura contain?"venous sinuses that drain the brain <img src=""lpyjAWNg0TIAyr9CYHvlhAqBKpZrfY3MXc0K9D6ZKsllHHmrCLHXiW92ltxZDUO91VhvYpdom1BCkWZWSs9hN1Wgij0gKjZQZHcXtd9OI8mD09a_7LE.png"">" Role of arachnoid venous sinuses"protrude into veins to secrete CSF <img src=""lpyjAWNg0TIAyr9CYHvlhAqBKpZrfY3MXc0K9D6ZKsllHHmrCLHXiW92ltxZDUO91VhvYpdom1BCkWZWSs9hN1Wgij0gKjZQZHcXtd9OI8mD09a_7LE.png"">" What is meningitis?"Infection in the subarachnoid spaces leads to recruitment of immune cells and inflammation → increases intracranial pressure that can disrupt blood flow and damage brain tissue" Diagnosis, symptoms, & treatment of meningitis<div>Diagnosed with lumbar puncture</div><div> </div><div>Common symptoms:</div><div><ul><li><div>Headache</div></li><li><div>Neck stiffness</div></li><li><div>Fever</div></li><li><div>Altered mental state</div></li></ul><div>Treatment involves antibiotics</div></div> What is CSF made of?mostly water and ions, not much protein or cells Role of CSF in brainbuoyant support for brain, sets extracellular K+ conc. Circulation of CSF"produced in ventricular system, flows throughout cerebrum and drains down to spinal cord <img src=""LdxuHAdwniD9lPZeQJ62jXN96d_8AvkbxQFyeSAuGtrpd_Wk3rAZtLRtRImTutFtAKjNqgGsUfPU6hlN8w0wX7qRaie86nsMVQxary4x7bnsq4Ttk-M.png"">" Where is most of the CSF in the brain located?subarachnoid space of the meninges Describe location of the lateral ventricles"<ul><li>one located in each cerebral hemisphere</li><li>anterior horn extends into frontal lobe</li><li>posterior horn extends into occipital lobe</li><li>inferior horn extends into temporal lobe</li></ul><div><img src=""rGtKylrkKl951pSKQpIyoNG15tN2CKmDhv9vuB8isSMz7E94eO8kjbPHPnu_biOzNIaIuT_hDMHCKTuHLKa5yZO3GYmLSMZpkaziL15vEjR2DyEaQ34.png""> </div>" Describe the anatomy and location of 3rd ventricle"<ul><li>divides thalamus & hypothalamus into L/R</li><li>optic recess borders supraoptic nucleus</li><li>infundibular recess is just posterior to the optic chiasm</li></ul><div><img src=""zHSdVPuHZoMUp8IAzZkmu4mC5t5qRMRmr3EckLdBaV0Gc2cdfoJEpYcRwscBwrAk7xmzAZBCjQvdDi30MiA8LXidiNsLwkOU-dbORHXEcAR3-qcOR80.png""> </div>" Describe the anatomy & location of 4th ventricle"<ul><li>located @ junction of pons & medulla</li><li>CSF drains from 4th ventricle to both central canal of spinal cord & subarachnoid cisterns</li></ul>" What produces CSFchoroid plexus Composition of choroid plexus"<ul><li>made of mostly epithelial cells</li><li>choroid fissue produces gaps in pia that allow for diffusion of water</li></ul><div><img src=""Z6ozqSNI2BG3H4RXFCET2isA4dit0lZUKrAubjwUO47ORxF_xAHpZfiqG9EXsHWwGfF6tDR37b7Cbq2xmaFZ6AXA0KhOQ8NI5TFfv9GWwSAdNaQv2cv.png""> </div>" How is CSF formed, and what is it made of?<ul><li>Formed by filtration of water from blood & active ion transport</li><li>Ca2+, K+, Mg2+, Cl-</li></ul> How is CSF different from blood?<ul><li>Lower Ca2+ and K+</li><li>Higher Mg2+ and Cl-</li></ul> Describe the route for flow of CSF"Lateral ventricle → 3rd ventricle → through cerebral aqueduct to 4th ventricle → central canal & subarachnoid cisterns to fill subarachnoid space" What is the flow of CSF due to?"<ul><li><div>Continuous production of CSF produces pressure that pushes fluid out of the lateral ventricles</div></li><li><div>Pulsing of blood vessels throughout the tissue causes a small amount of movement that puts pressure on CSF to flow</div></li></ul>" How does the brain receive blood input?Vertebral & carotid arteries What arteries merge to form a single artery in the brain?"Vertebral arteries merge to form basilar artery <img src=""IUVPldvSX-ssgj9dAQrTFcavb7SCh8D4ePWxmzJ9qJ7n0us23Q9DccMImx9C1kBdaTM60JqL7RT32JKqO0LQSCKSmm2bO2C5gjcSEqechB0EWYd2V2a.png"">" Function of circle of Willis"<ul><li>because of arterial pressure, blood doesn't normally circulate through the circle</li><li>in the case of a blockage, circle of Willis allows for blood flow to all major arteries</li></ul><div><img src=""LltyKrNLzf4krmAaoF9Is09Ct4561m5kTu13NYZjBGK6DjM71btZOeygJ_URdUfL9if6Vt405W9yvQlt3CceTQujO3BxQJ8Ro350iNgIiJqGa_Zg9cl.png""> </div>" Key cerebral arteries and their targets (anterior, middle, posterior)<ul><li>Anterior - anterior medial side of frontal & limbic lobes</li><li>Middle - lateral areas (motor cortex, somatosensory cortex, auditory processing areas)</li><li>Posterior - medial aspect of posterior & inferior areas (occipital)</li></ul> How does blood drain from the brain?Superficial veins drain into superior sagittal sinus (SSS), which then drain through the jugular veins What is a hematoma, and what can it cause?<ul><li>pool of blood outside of the blood vessels</li><li>causes herniation of the brain (protrusion of one part of the brain to another)</li></ul> What is angiography?"Contrast dye injected into bloodstream → allows visualization of blood vessels with X-rays" Ischemic stroke + treatment<ul><li>blockage in artery leading to brain</li><li>clot can be dissolved with enzyme (TPA) or physically removed</li></ul> Hemorrhagic stroke + treatment<ul><li>bursting of blood vessels supplying blood to brain</li><li>treatment involves monitoring and surgical drainage prn</li></ul> What is the BBB made of?"<ul><li>tight junctions between epithelial cells that line the capillaries</li><li>is impermeable to most drugs</li></ul><div><img src=""Pn7N5csLYd1lkik4a7ytH8z50LkMBK3yi2u5lgtYidk4vRn-DYzdKVFRn94AKN_lGUsGBcFUy1HzDFkbWQspnZVNpNAM9GTYwEMM9PfsLARHB318xFA.png""> </div>" Role of astrocytes in BBB"relay of signals between the brain and barrier <img src=""Pn7N5csLYd1lkik4a7ytH8z50LkMBK3yi2u5lgtYidk4vRn-DYzdKVFRn94AKN_lGUsGBcFUy1HzDFkbWQspnZVNpNAM9GTYwEMM9PfsLARHB318xFA.png"">" Paracellular aqueous pathway"water soluble agents can diffuse across tight junctions from blood into the brain  <img src=""-bPHlndveVTAryVsqWOwXSY-HdXHuKUpsZM6jN_7SC7u1NaxaT9C3LjorAqymeJyEkCYujLU6Ig60upqK5b5BF90qKY7HvVhuQjTpg50gzxL9RHqqe9.png"">" Transcellular lipophilic pathway"lipid-soluble agents diffuse across endothelial cells into the brain <img src=""-bPHlndveVTAryVsqWOwXSY-HdXHuKUpsZM6jN_7SC7u1NaxaT9C3LjorAqymeJyEkCYujLU6Ig60upqK5b5BF90qKY7HvVhuQjTpg50gzxL9RHqqe9.png"">" Transport proteins in BBB"transports glucose, AAs, and nucleosides through endothelial cells <img src=""-bPHlndveVTAryVsqWOwXSY-HdXHuKUpsZM6jN_7SC7u1NaxaT9C3LjorAqymeJyEkCYujLU6Ig60upqK5b5BF90qKY7HvVhuQjTpg50gzxL9RHqqe9.png"">" Receptor-mediated transcytosis in BBB"Ligands bind to receptor → ligand-receptor complex gets endocytosed into the epithelial cell → ligand is exocytosed into the brain <img src=""-bPHlndveVTAryVsqWOwXSY-HdXHuKUpsZM6jN_7SC7u1NaxaT9C3LjorAqymeJyEkCYujLU6Ig60upqK5b5BF90qKY7HvVhuQjTpg50gzxL9RHqqe9.png"">" What molecules cannot diffuse across the BBB?large hydrophobic molecules What are circumventricular organs?"<ul><li>areas without a BBB that surround ventricles</li><li>allows for free flow of extracellular substances between the brain and blood</li></ul>" Name the circumventricular organs in the brainsubfornical organ, pineal gland, median eminence What are fenestrations?"fold-producing pores in the endothelial lining that allow for diffusion of small molecules & proteins" What are pinocytotic vesicles"injection of vesicles that take up extracellular stuff" "Ways in which stuff can pass from blood to brain in the barrier-free vessels"Fenestrations & pinocytotic vesicles

BIPN 160 - FINAL EXAM

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BIPN 160 - FINAL EXAM

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