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This 28 page Class Notes was uploaded by Maddie Rapp on Thursday October 8, 2015. The Class Notes belongs to PSYC2070 at The University of Cincinnati taught by Dr. Sheila Flemming in Fall 2015. Since its upload, it has received 5 views. For similar materials see Biopsychology in Psychlogy at The University of Cincinnati.
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Date Created: 10/08/15
Cranial Nerve I II III IV V VI VII VIII IX XI XII Olfactory Optic Oculomotor Trochlear Trigeminal Abducens Facial Vestibulocochlear Glossopharyngeal Vagus Accessory Ilypoglossal Cranial Nerves General Function Sense of Smell Sight Eye Movement Eye Movement Face sensory motor Eye Movement Face expression and sensory Hearing and Balance Tongue and Throat motor and sensory Parasympathetic Head neck shoulder movement 8 swallowing Speech Chewing and Swallowing Cranial Exit Opening Cribriform Plate of the Ethmoid Optic Foramen Superior Orbital Fissure Superior Orbital Fissure Superior Orbital Fissure Superior Orbital Fissure Stylomastoid Foramen Internal Acoustic Meatus Jugular Foramen Jugular Foramen Jugular Foramen Hypoglossal Canal Sir Charles Bell Scottish surgeon who described the facial nerve Belly s Palsy temporary facial paralysis resulting from damage or trauma to the facial nerves 7th Cranial Nerve facial nerves Facial Nerve important for eye blinking and closing smiling and frowning Disruption of the facial nerve results in facial weakness or paralysis Causes viral infection meningitis herpes simplex cold sore virus The disorder also associated with the flu and other problems such as high blood pressure diabetes and middle ear infection Treatment steroids antiviral drugs Both Sylvester Stallone and George Clooney have been reported to have experienced Bell s Palsy and recovered Brain Development Principles Proliferation The generation of neurons Migration Movement of cells away from proliferation zones Differentiation The acquisition of neurochemical signaling factors and cellular connec ons The processes that contribute to brain development range from the molecular events of gene expression to environmental input Brain Development Brain development begins on embryonic day 14 and takes two weeks to get to the neural tube Most important milestones gastrulation neurulation Gatrulation undifferentiated embryonic tissue specializes into three primary germ layers This is complete by E18 Ectoderm Mesoderm Endoderm Neurualtion follows gastrulation and is the process that gives rise to the neural tube It begins at E18 and is complete by E28 Primary neurulation Secondary neurulation Brain Development Gastrulation and neurulation are the foundation for all further Plurlpotent Stem Cells milestones in brain development Failure of either of these events f mgr eniliz egg can cause serious neural defects and can compromise the viability soquot embryo of the organism Cultured gpiunooienp undifferentiated Before onset of gastrulation the S em39s embryonic cells have not differentiated and are called Embryonic stem cells Blood cells Embryonic stem cespluripotentcapabe of generating all the cell lines in the body Cardiac muscle Formation of the Neural Plate During gastrulation the embryonic stem cells differentiate into three progenitor lines progenitorcapabe of dividing and can produce other cell types but the range of cell types they can become is restricted compared to embryonic stem cells The three progenitor lines are Ectodermal Mesodermal Endodermal The three progenitor lines are organized into distinct layers called primary germ layers Each layer contains progenitors for different types of body tissue and are called the ectodermal germ layer mesodermal germ layer endodermal germ layer This three layered structure is called trilaminar discneural plate A Normal development Formation of the Neural Tube Neurulation begins with the induction of neural progenitor cells during gastrulation but the main changes in tube formation begin at E18 and are completed by E28 Neurulation is the set of events that lead to the generation of the primitive nervous system structure called the neural tube Formation of the Neural Tube Four basic processes involved in primary neurulation 1 formation of the neural plate happens during gastrulation 2Shaping of the neural plate 3 bending if the neural plate 4 closure of the neural tube Shaping embryo begins to elongate in a process called convergent extension Bending of the neural plate involves contraction of actin microfilaments and apoptosis Apoptosis programmed cell death that differs from other types of cell death such as necrotic or pathological in both the sequence of events and the molecular signaling involved Apoptosis is highly regulated and thought to facilitate bending of thetube 13 Neural plate Shaping r Neural 1b Elevation DEVELOPMENTAL BIOLOGY Seventh Edition Figure 123 Part 1 Sinauer Assocmtes Inc 11 2003 All rights reserved A 4 u ark w 5 V v v 39 w iq bar x x E 4 1 1 f V w 63 l A a j A J 239 Sk39 3 v CT 64 7 139 LS fhv 7 Neural tube DEVELOPMENTAL BIOLOGY Seventh Edition Figure 123 Part 2 Sinauer Associates Inc 13 2003 All rights reserved A Normal development Neural plate presumptive p Neural groove epidermis Ecadherin Ncadherin Neural tube DEVELOPMENTAL BIOLOGY Seventh Edition Figure 126 Part 1 Sinauer Associates Inc 2003 All rigms reserved Neurulation in Mammals Neural tube closes in several places along axis not in A to P direction If any one of those closures fails neural defects result A Neural fold Pericardial bulge Otic placode Somites Cut edge 39 of amnion B C Anterior F neuropore Pericardial bulge quot Somlte 4 Posterlor neuropore 23 days DEVELOPMENTAL BIOLOGY Seventh Edition Figure 125 Part 1 Sinauer Assocvates Inc Iii 2003 All rights reserved Neural Tube Defects Neural tube defects NTD Failure of neural tube closure Results in multiple malformations and in severe cases can compromise viability 4 5 Normal I A rochischisis Spina bifida occul ra meningocele meningomyelocele C Cnnbnchhchids Open coin Md Formation of the Neural Tube A lateral view of the brain of an embryo after 4 weeks of development showing the neural tube Diencephalon Mesencephalon covered by covered by Mesencephalon r Rhombencephalon 39 39 Cerebrum cerebrum cerebrum cord Prosencephalon Neurocoel f A lateral view of the brain of a 5weekold embryo IW quoti 39 I quotT quot V A I Prosencephalon l Rhomboncephalon l Metencephalon Myelencephalon wM Elulla Diencephalon oblongata m f n l quot V quot 9 39 M i i e um i u v I n quotV J h 39 39 wq as w 39 quot quot839 COM a V 39 I l 39 a a W 1 I Brain development in a child showing the cerebrum covering other portions of the brain Telencephalon 39 2011 Pearson Education Inc Formation of the Neural Tube Closure of the neural tube fusion of tissue at the tips of the neural folds Establishment of new class of cells neural crest cells and somites After neural tubeclassic embryonic subdivisions prosencephalon forebrain structures mesencephalon midbrain structures rhombencephalon hindbrain structures The three primary vesicles further subdivide creating five secondary vesicles Brain Development Neurons and Glia Proliferative zonesregions Ventricular zone around lateral ventricles Subventricular zone adjacent to ventricular zone Ganglionic eminences this area will become basalgangHa projection neurons are produced early in the ventricular zone and later in the subventricular zone interneaurons are produced in the ganglionic eminence and ventricular zones in primates and only in the ganglionic eminence in mice Glial cellls that provide support for neurons are produced in both the ventricular zone and ganglionic eminence Brain Development Neurons and Glia Glial cells Astrocytessupport framework modulate neuron activity and responsive to injury Oligodendrocytes produce myelin Microgliasupport immune response and clean up debris Most neurons are generated during the 2nd trimester At peak of proliferation 200000 generated each minute Neocortex forms a sheet that covers the surface of the brain Brain Development Neurons and Glia Cortex Paleocortex phylogenetically older division of the ocortex and forms olifactory cortex Archicortex also phy Older and gives rise t hippcampus Neoco ex Neocortex humans area1850 cm2 rats area 6cm2 Thickness humans 25 mm across regions rats 12mm Vertical thickness is conserved across species lllllL39 mnnkc Ilumm Neocortex 6 laminae Human Hiram mphm Neuronal Migration 3 modes of migration somal translocation radial glial locomotion tangential migration Somal translocation simpler mode of migration seen in early in development and small distances need to be traveled Radial glial locomotion dominant mode of migration Radial glial provide structural scaffold for most neuronal migration and can actually produce new neurons Tangential migration is used by cells leaving the ganglionic eminences Apoptosis Synapse Overgrowth and Pruning When axons initially reach their targets they form synapses with several cells Postsynaptic cells strengthen connectiom with some cells and elimination connections with others The formation or elimination of these connections depends upon input from incoming of axons Apoptosis Synapse Overgrowth and Pruning Significant numbers of new neurons die during the development process Via apop osis programmed cell death Neurons a pear to complete for nerve rowthfac or NGF and those that tail 0 obtain this stimulation die Synapses follow a similar pattern of overproduction followed by quotpruningquot Dendrite Axon terminal E 39 1 I 7 39 it Nco Rvo l l f a Ir Cell body ltquot gt t 1quot 39 73 39gt od n n Schwann cell myclin ccccc us Apoptosis Synapse Overgrowth and Pruning Blooming and pruning Synaptic overproduction peaks about 4 months after birth Prefrontal cortex overproduction peaks about 1 year of age Adult density achieved in adolescence Heredity and environment affect timing Brain Development Overgrowth and Pruning Some theorists refer to the idea of the selection process of neural connections as neural darwinism In this competition amongst synaptic connections we initially form more connections than we need The most successful axon connections and combinations survive while the others fail to sustain active synapses Brain Development Overgrowth and Pruning Early stages of brain development are critical for normal development later in life Chemical distortions in the brain during early development can cause significant impairment and developmental problems Expenence Rats raised in an enriched environment develop a thicker cortex and increased dendritic branching Measurable expansion of neurons has also been shown in humans as a function of physical activity The thickness of the cerebral cortex declines in old age but much less in those that are physically active