NSC 4352 1st Edition Exam # 1 Study GuideLecture 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 phrēn ("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 populationaffected. • 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 thefrontal 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 thebrain 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 makeproteins. •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.Inorder 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 synthesize proteins needed in some organelles or for exocytosis (i.e. transmitters) are“membrane bound” to the rough endoplasmic reticulum. The newly produced polypeptide chains are inserted directly into the ER by the ribosomes and are then transported to their destinations through the secretory pathwayThe 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 theirfinal destinations, e.g. the cell membrane or secretion.•The Golgi apparatus has