II. Study Guide for Exam IIA. Lecture 8 Developmental Neurogenesis1. Be able to define the terms zygote, blastula, and gastrula.a. Zygote: from fertilization to 4 days oldb. Blastula: hallow ball of cells forms after 4 daysc. Gastrula: 3 layered ball of cells forms 7-10 days2. Be able to define the terms ectoderm, mesoderm, and endoderm, and know which layer forms the nervous system.a. Ectoderm: outer layer; forms skin and nervous system b. Mesoderm: middle layer; forms muscle, blood, and bonec. Endoderm: inner layer; forms internal organs – lungs, liver, intestines 3. Be able to define neural plate, neural tube, and neural crest and know what structures they form.a. Neural plate: part of the back ectoderm that forms the neural tube by folding in on itself b. Neural tube: hollow tube of cells that eventually forms the spinal cord and brainc. Neural crest: these cells eventually migrate out and form peripheral nerves 4. Know the 6 main processes that form the nervous system during development, and know when they occur, which ones are completed by birth and which ones continue postnatally.a. Cell proliferation – a few weeks after conception and is completed before birthb. Cell migration – starts 8-9 weeks post conception and is completed before birthc. Cell differentiation & maturation – starts a few weeks after conception and is mostly completed by birth d. Synaptogenesis – starts during prenatal development and continues into late childhoode. Cell death and synaptic pruning - f. Myelination – just after birth and continues into young adulthood 5. Be able to describe the process of neural cell migration.6. Know the 2 different types of migration, the processes used by cells to carry out these types of migration, and know the two examples in class involving these processes of migration.a. Tangential – moving up/down or aroundi. Migration of neural crest cells to form Schwann cells and neurons in peripheral nerves b. Radial – moving out from center i. Migration of cerebral cortical neurons to form the layers of the cerebral cortex7. Know what master regulatory genes are and what role they play in neural development, and what process they are most associated with.a. Master regulatory genes: genes that produce a protein that then turns on neuron-specific genes i. Play a role in morphological differentiation (cells taking on their adult forms)1. Grow dendrites – increases surface area for synapse formation2. Extend axons 8. Be able to list the processes associated with neuronal maturation.a. Chemical differentiation – when master regulatory genes are activated which in turn produce proteins that turn on certain neural genesb. Morphological differentiation – when a cell takes on its adult form 9. Understand the role of chemoattractants and adhesion molecules in the process of axonal extension.a. Secretion of chemoattractants from the target cell guide the axons to themb. Cell adhesion molecules grasp the axon and adhere it to the target cell 10. Describe the process of synaptic development, specifically be able to list the events occurring in both the presynaptic axon and the postsynaptic dendrite.a. Presynaptic axon – synthesizes and stores neurotransmitter vesicles b. Postsynaptic dendrite – forms and inserts neurotransmitter receptors into the membrane11. Understand the processes of neuronal cell death and synaptic pruning and how they contribute to normal neural development.a. Neurotrophins – special chemicals secreted by postsynaptic neuronsi. Promote neuronal growth and survival of presynaptic neurons ii. Neurons with a stronger connection get more neurotrophin therefore a weaker connection means less neurotrophin and the neuron will eventually die12. Know which regions of the brain undergo myelination first and which generally undergo it last.a. Regions controlling sensory analysis and simple movement myelinate firstb. Regions involved with decision making and complex sensory analysis myelinate last B. Lecture 9 Maturation, Environment and Neural Development1. Be able to describe generally the evolution of grasping behaviors in infants and know which developmental processes are thought to be involved in them.a. 2-4 months – hand orients toward object with a claw like graspb. 6-8 months – uses fingers individuallyc. 10 months – fine pincer grasp for holding small objects d. Myelination of motor cortex neuronse. Pruning of cells in hand region of cortex f. Increased dendritic maturation in motor cortex neurons2. Be able to describe the developmental neural changes associated with language development in young children.a. increased cortical thickness in speech areas of cortexb. pruning of speech sound areas of other languages 3. Know the 4 different stages of Piagetian development and the developmental neural changes associated with them.a. Sensorimotor stage – object permanence; cause and effectb. Preoperational stage – form mental, word, and drawing representations of thingsc. Concrete operations – mentally manipulate dimensions, mathematics, conservation of mass (glass ex)d. Formal operations – abstract reasoning – strategize, more tactical 4. Know what neural changes are associated with being raised in an enriched environment in rats.a. Cortical neurons are larger, more complex (branching and connections)5. Be able to define adult neurogenesis and know what can cause it to occur, and in what brainregion it occurs.a. Adult neurogenesis – new neuron formation in the hippocampusb. Affected by exercise 6. Know the symptoms of autism spectrum disorder and know the neural changes associated with it.a. Social deficitsb. No eye contactc. Repetitive motor behaviors d. Undergrowth/under-connectivity – may reflect defective proliferation, differentiation, dendritic branching, and/or synapse formatione. Overgrowth/over-connectivity – may reflect defective pruning of cells or synapses leading to over stimulation of these areas 7. Know the symptoms of mental retardation and know the neural changes associated with it.a. Significantly impaired cognitive functioning and deficits in adaptive behavior b. Decreased brain growth – reduced neural number due to decreased proliferation during prenatal developmentc. Decreased dendritic spines and branches particularly in cortical neurons 8. Know the factors allowing most of us to develop normal brains.a. Overproduction of neurons and synapsesb. Synaptic plasticity – allow us to overcome losses