Study Guide Chapter 4 - Neurotransmitters and Psychoactive Drugs PDF

Study guide Chapter 4 Definition and characteristics of neurotransmitter: communicate locally across the synapse Synthesized by neuron Released in response to an AP Measurable effect on postsynaptic cell Can duplicate drug effects and actions Some mechanisms to remove th...

Study guide Chapter 4 Definition and characteristics of neurotransmitter: communicate locally across the synapse Synthesized by neuron Released in response to an AP Measurable effect on postsynaptic cell Can duplicate drug effects and actions Some mechanisms to remove the effects Types of post-synaptic receptors (ionotropic: ligand gated ion channels, has 2 domains; binding site, and membrane spanning one that forms an ion channel, has RAPID postsynaptic effects vs. metabotropic: G protein coupled receptors, do not have ion channels, 2 binding sites; binding site, and domain that binds to G proteins) and their characteristics Categories of neurotransmitters acetylcholine: used at neuromuscular junction, receptor=nicotinic (I) and Muscarinic (M) autonomic NS and CNS (learning and memory) monoamines (catecholamine: DA: dopamine- synthesized by tyrosine and receptors are metabotropic and involved in reward, receptor=DAT (M), NA: norepinephrine- synthesized by tyrosine, uses diffusion, receptor=AD-R (M) involved in arousal and fight/flight ; Indolamine: Serotonin and melatonin- synthesized from tryptophane, receptor= 5-HT-R (M) and is involved in sleep, appetite, depression/anxiety) Amino acids (glutamate: critical in memory; 1. binds to AMPA and NMDA, 2. AMPA activates and Na+ enters, 3. moderate local depolarization, 4. Mg2+ dislodges from NMDA, 5.  Study guide Chapt 4 Types of psychoactive drugs; depressants- alcohol, barbiturates, and benzos. stimulants- caffeine, nicotine, cocaine, and amphetamines. psychedelics- marijuana, LSD, psilocybin, PCP, and ecstasy. opiates- morphine, codeine, and endorphins Mechanism and effects of alcohol: GABAa recptor=agonist: neural inhibition; antianxiety, sedative effects, NMDA receptor=antagonist: memory loss Mechanism and effects of ecstasy: blocks reuptake of 5-HT, increases 5-HT, euphoria, long term effects are depression, anxiety, and memory loss  Chapter 3 Neuron: structure (soma: cell body; cytoplasm+ cytosol and organelles, nucleus/DNA, provies metabolic and synthetic support, dendrites: conduct stimulation from neurons, spines: membranous protrusion that receive input from synapse of an axon, substrate for synaptic transmission, high number of possible contacts between neurons, spines can change rapidly in response to environmental stimuli, axon; slender projection of a neuron that typically conducts electrical impulses away from the neuron’s body, collaterals: ends with axon terminal, axon terminal: most distal portion of a neuron’s axon and is critical for neural communication, cytoskeleton: microtubes: transport material to and from cells, neurofilaments: structural support of axon, microfilaments: reorganization of neural branches) role and function of each part of the neuron (including cytoskeleton: transports- microtubes, structural support- neurofilaments, reorganizes- microfilaments): dendrites- conduct electrical signals, dendritic spine- have plasticity, and membranous , and are a substrate for synaptic transmission, (cell body)- integrates incoming signals and gives outgoing signal to axon has DNA, axon- passes electrical signals to dendrites another cell classification of neurons based on morphology and function Glial cells: different types, their location and their role: astrocytes: Structural support for neurons: They are involved in the physical structuring of the brain. Nutritional support for neurons: They can fuel neurons with glucose and provide neurons with nutrients such as lactate. Synapse isolation: They prevent neurotransmitters to leak outside the synapse, Resting potential: concentration of ion on each side of the membrane: 70mV more negative than the outside -70mV diffusion: moves molecules from high to low concentrated areas roles, characteristics and functioning of ion channels: electrically charged ions move passively and ion pump: electrically charged ion particles move across the membrane using energy Action potential: different phases in relation to the opening of ion channels/pump: depolarization: positively charged sodium ions (Na+) suddenly rush through open voltage-gated sodium channels into a neuron repolarization: returns the membrane potential back to the resting membrane potential hyperpolarization: The opening of the ion channel (Cl-) results in a net gain of negative charge. This moves the potential further from zero. all or none principle: amplitude of an a.p is dependent on the amount of current that produced it OCCURS FULLY OR NOT AT ALL and always reaches +40mV , threshold: membrane potential necessary to activate AP refractory periods (absolute: no stimulus can produce another AP vs relative: cell gain produces another AP with stronger stimulus) propagation of action potential (myelinated axon: conduct signal faster, saltatory conductance in myelinated, myelin blocks ion movements vs non-myelinated: passive conductio in non-myelinated, ) Synapse: Structure: a small gap in between neurons including the; presynaptic neuron, neuron cleft, and postsynaptic neuron Functioning and characteristics of electrical synapses: small synaptic cleft, transmission by direct ion movement = very simple communication Functioning and characteristics of chemical synapses (steps from the action potential to release of neurotransmitter, to postsynaptic current) Deactivation of neurotransmitters: diffusion: diffuses from high to low concentrate, degradation: enzymes break down the neurotransmitter into substance with no effect on receptor channel, reuptake: neurotransmitter can reenter through BBB channels Characteristics of EPSP: results in neg gain of + ions, membrane is depolarized, potential=close to 0 and potential is closer to -50mV vs IPSP: results in net gain of – ions, potential is further from 0 and is hyperpolarized and is further away from threshold (including temporal and spatial summation) 2 types of neuromodulations: presynaptic facilitation: high number of neurotransmitters release by postsynaptic axon as result of input from presynaptic axon, presynaptic inhabitation: low number of neurotransmitters release by postsynaptic axon as a result of input from the presynaptic axon  Chapter 2 Orientation of the brain and types of section Basic anatomy of the CNS: meninges (structure and roles): membranes that make up the nervous system that have 3 main layers; dura matter, arachnoid membrane, and pia matter CSF (roles, synthesis): colorless fluid in brain and spine that flows through the ventricles through the subarachnoid and gets absorbed through the bloodstream - protection, clears wast4e, maintains intercranial pressure, Blood supply (name of blood vessels) + Blood brain barrier (role): blood is received through the vertebral and carotid arteries and the BBB is semipermeable which means it only lets specific things through to protect the brain Central nervous system: general anatomy of spinal cord: cervical, thoracic, lumbar, sacral, and coccygeal different structures of the brain and their main functions: hindbrain= medulla: connects higher levels of the brain to the spinal chord, pons: relays messages from the cortex and cerebellum, cerebellum: plays important role in motor control midbrain= tectum: dorsal position involving auditory and visual processing, tegmentum: ventral position involving many homeostatic and reflexive pathways (pain, reward, movement) forebrain= diencephalon (thalamus= sensory center, hypothalamus= regulatory center), telencephalon (cortex: outermost layered structure of neural tissue of the brain with 6 layers, 2 hemispheres, and 4 lobes, basal ganglia: planning, movement, and  Chapter 1 Orientation of the brain and types of section Basic anatomy of the CNS: meninges (structure and roles): membranes that make up the nervous system that have 3 main layers; dura matter, arachnoid membrane, and pia matter CSF (roles, synthesis): colorless fluid in brain and spine that flows through the ventricles through the subarachnoid and gets absorbed through the bloodstream - protection, clears wast4e, maintains intercranial pressure, Blood supply (name of blood vessels) + Blood brain barrier (role): blood is received through the vertebral and carotid arteries and the BBB is semipermeable which means it only lets specific things through to protect the brain Central nervous system: general anatomy of spinal cord: cervical, thoracic, lumbar, sacral, and coccygeal different structures of the brain and their main functions: hindbrain= medulla: connects higher levels of the brain to the spinal chord, pons: relays messages from the cortex and cerebellum, cerebellum: plays important role in motor control midbrain= tectum: dorsal position involving auditory and visual processing, tegmentum: ventral position involving many homeostatic and reflexive pathways (pain, reward, movement) forebrain= diencephalon (thalamus= sensory center, hypothalamus= regulatory center), telencephalon (cortex: outermost layered structure of neural tissue of the brain with 6 layers, 2 hemispheres, and 4 lobes, basal ganglia: planning, movement, and