NSC 4352 1st Edition Exam 1 Study Guide Lecture 1 Studying the Nervous System Different levels of analysis from behavior to ion channels and genes Working memory Active maintenance of task relevant information used to guide forthcoming behavior Schizophrenia One of the most disabling mental disorders has the unfortunate circumstance of being one of the least understood Schizophrenia from the Greek roots schizein to split and phr n mind is a psychiatric diagnosis that describes a mental disorder characterized by abnormalities in the perception or expression of reality Symptoms include auditory hallucinations paranoid or bizarre delusions and disorganized speech and thinking positive symptoms with significant social or occupational dysfunction negative symptoms Onset of symptoms typically occurs in young adulthood with approximately 0 5 of the population affected Studies suggest that genetics early environment neurobiology psychological and social processes are important contributory factors some recreational and prescription drugs can cause or worsen symptoms Current psychiatric research is focused on the role of neurobiology but no single organic cause has been found Symptom groups positive psychotic symptoms delusions hallucinations bizarre thoughts disorganized speech Positive symptoms are those that occur in addition to normal experiences main diagnostic criteria traditional focus of pharmacological treatment negative symptoms social withdrawal with flat affect poor motivation apathy impairment of goal related behaviors inattentiveness poor insight Cognitive symptoms deficits in attention and memory are considered a 3rd group Deficits in working memory are core cognitive symptoms in schizophrenics Levels of Analysis Behavior Pharmacology Functional imaging EEG Gross anatomy Neurons Synaptic interactions Pharmacology Intracellular mechanisms Genes The loss of working memory function in schizophrenia is related to changes in dopamine function in the frontal cortex The brains of schizophrenic patients show celltype specific reductions in GABA interneurons Studying the Nervous System Functional imaging in humans fMRI measures changes in regional blood flow active cells use more oxygen rich blood currently offers the best approach for visualizing brain function based on local metabolism when a brain area is activated by a special task it begins to use more oxygen and within seconds the brain microvasculature responds by increasing the flow of oxygen rich blood to the active area Animal Models Skinner box rat working for food pellet light signals reward which leads to dopamine release a more detailed picture of the events underlying the mitotic or any other neural circuit can be obtained by electrophysiyoligcal recording which measures the electrical activity of a nerve cell There are 2 approaches to this method extracellular recording where an electrode is placed near the nerve cell of interest to detect its activity and intracellular recording where the electrode is placed inside the cell of interest Extracellular recording is particularly useful for detecting temporal patterns of an action potential activity and relating those patterns to stimulation by other inputs or to specific behavioral events Intracellular recording can detect the smaller graded changes in electrical potential that trigger action potentials and thus allow a more detailed analysis of communication between neurons within a circuit Lecture 2 The Cell Nucleus The nucleus contains the cell s genome and serves as control center The nucleus contains the nucleolus and chromosomes necessary for the production of proteins within the cell The genetic information of an organism is coded within strands of DNA deoxyribonucleic acid from which the chromosomes are made The nucleus contains the nucleolus and chromosomes The nucleolus produces ribosomes Genes the subunits of a chromosome induce the production of messenger ribonucleic acid mRNA when activated mRNA is a duplicate of the information contained in the gene transcription mRNA leaves the nucleus and attaches to a ribosome serving as a template for the production of a protein Ribosomes DNA is used to make RNA which in turn is used to make proteins The DNA sequence in genes is copied into messenger RNA mRNA Both these steps occur in the nucleus Ribosomes make proteins from amino acids Ribosomes read the genetic information in the RNA and use it to create proteins Translation Translation protein synthesis In order to translate RNA into proteins ribosomes bind to mRNA and use it as a template for the correct sequence of amino acids in the protein The amino acids are attached to transfer RNA tRNA which enter the ribosome and bind to the messenger RNA The ribosome moves along the mRNA reading its sequence and producing a chain of amino acids In order to translate RNA into proteins ribosomes bind to Free ribosomes Free ribosomes can move about anywhere in the cytosol but are excluded from the cell nucleus and other organelles Proteins that are formed from free ribosomes are released into the cytosol and are used within the cell Membrane Bound RIbosomes Ribosomes that proteins organelles or i e membrane rough reticulum The polypeptide inserted ER by the are then their through the pathway synthesize needed in some for exocytosis transmitters are bound to the endoplasmic newly produced chains are directly into the ribosomes and transported to destinations secretory The endoplasmic reticulum ER Network of tubules vesicles and cisternae throughout cells The rough endoplasmic reticulum RER synthesizes proteins Is studded with ribosomes Works with the Golgi complex to target new proteins to their destinations The smooth endoplasmic reticulum synthesizes lipids and steroids metabolizes carbohydrates and steroids In spines it regulates calcium levels and the attachment of receptors onto the membrane The Golgi apparatus Factory in which proteins received from the ER are further processed and sorted for transport to their final destinations e g the cell membrane or secretion The Golgi apparatus has a front receiving end Cis face and a back end Trans face from which molecules are discharged in secretory vesicles The most common alteration are addition of sugar chains glycoprotein adding sugar to a protein glycolipid adding sugar to a lipid The modified proteins lipids collect in the cisternae which eventually bud off in a secretory vesicle Mitochondria cellular power plants Primary