NROSCI 0081: Drugs and Behavior Exam 1 Review Sheet PDF

NROSCI 0081: Drugs and Behavior Review Sheet Exam 1 Lecture 1 – How we study drugs - What is a drug? What is a psychoactive drug? o Understand that there’s different definitions for different contexts o A drug is an __exogenous_ chemi...

NROSCI 0081: Drugs and Behavior Review Sheet Exam 1 Lecture 1 – How we study drugs - What is a drug? What is a psychoactive drug? o Understand that there’s different definitions for different contexts o A drug is an __exogenous_ chemical not necessary for normal cellular functioning that significantly __alters___ the functions of certain cells when taken at relatively low doses. o A psychoactive drug are drugs that affect __thinking, mood, or behavior_, and depending on the intent of the individual, drug use can be considered instrumental or ___recreational______. Lecture 2 – Nervous System Structure and Function - What are the implications of Darwins’ findings in the context of animal research? o Animals and men both have minds o Animals can be used to study the brain - Theory of evolution, animal models (pros/cons) - Homeotic genes control the __development of the body__. o CNS organization ▪ Homeotic genes, when activated, produce a particular body part. These sets of genes are similar across species. - Four F’s - What are the properties of a successful nervous system (4 items)? o Reception (sensory neurons) ▪ Transduction o Transmission o Integration (interneurons) o Decision/action (motor neurons) - Simple sensorimotor circuit components (5 items): o Muscle o Receptor: muscle spindle o Transmission line from receptor to Spinal Cord: afferent neuron (sensory neuron) o Synapse: place where the sensory neuron “talks” to motor neuron o Transmission line from spinal cord to muscle: efferent neuron (motor neuron) - Neurons o Sensory, motor, interneuron ▪ Sensory neurons receive information from the __environment__ and are involved in ‘reception’. ▪ Motor neurons transmit information to muscle to perform __actions___. ▪ __Interneurons___ integrate information between sensory and motor neurons. - Spinal cord  o Afferent/Sensory, Efferent/Motor o Afferent/sensory neurons send information ___toward___ the central nervous system. o Efferent/motor neurons send information __away from___ the central nervous system. Brain organization and function: Mapping the Brain - Functional Neuroanatomy o Cerebral lobes ▪ Occipital, parietal, frontal, temporal ▪ The ___occipital____ lobe is responsible for early-stage vision. ▪ The ___parietal____ lobe is associated with somatosensation (touch and pain) and late-stage vision. ▪ The __temporal___ lobe is associated with memory, hearing, and language comprehension. ▪ The ____frontal____ lobe is associated with planning and signaling movement, working memory, and inhibition of inappropriate behaviors. o Roles of specific brain areas ▪ Including (but not limited to) hippocampus, cerebellum, limbic system, etc. The ___hippocampus___ is associated with memory consolidation and provides the organism’s context. The ___cerebellum__ is associated with motor planning and learning. The ___limbic system___ is a group of interconnected structures that are associated with emotional behavior and interpretation, sexual behavior, and contains primary reward and punishment centers. The __basal ganglia__ is a group of interconnected structures that control voluntary, smooth movement. ▪ Sulci and gyri (what they are, why we have them) ___Sulci___ are the grooves/ridges of the brain and __gyri___ are the bumps. Sulci and gyri serve to ___increase____ the surface area of the brain Lecture 3 – Neurons and Resting Potential - Parts of the neuron ▪ Soma, axon hillock, axon, axon terminal, dendrites ▪ The __soma__ is the cell body of the neuron. The __dendrites___ receive input from other neurons, the inputs from those neurons are integrated at the __axon hillock__. The output from a neuron is sent along the __axon__, and releases neurotransmitters from the __axon terminal__. - What is the principle of Dynamic Polarity? o __Electrical___ signals within a neuron flow in __one__ direction. - Neurons are classified into 3 functional groups: o __Sensory__ = afferent neuron o __Motor__ = efferent neuron o __Integration__ = interneuron - What is membrane potential? What is the resting membrane potential of a neuron?  o The difference in electrical charge between the inside and the outside of the cell is known as the ___membrane potential____. The resting membrane potential of a neuron is about ___-70 mV___ (don’t forget to include units!), and the inside of the neuron is ___negative___ with respect to the outside. - What are the 3 components of presynaptic transmission? o Presynaptic neuron sends an electrical signal from the __axon hillock__ to the __axon terminal__. o At the synapse the __electrical signal__ gets converted into a __chemical signal__. o The postsynaptic neuron converts the __chemical signal__ into an __electrical signal__. - How is resting membrane potential measured? o A _____microelectrode____ is inserted through the membrane which measures the electrical potential inside the axon relative to the outside. - How are ions distributed across the neuronal membrane? o ___Na+__ and ___Cl-___ are more highly concentrated outside the neuron, whereas __K+__ and __negatively charged proteins (A-)__ are more concentrated inside the neuron. - What happens if you change the ion concentrations in the extracellular fluid? What if you increase the permeability of the cell membrane? o If you increase the extracellular concentration of Na+, there will be __no__ effect on the resting potential. If you increase the extracellular concentration of K+, it will ___depolarize__ the membrane potential. o If you increase the permeability of the cell membrane to Na+, it will enter the cell and ___depolarize___ the membrane potential. If you increase the permeability of K+, it will leave the neuron and ___hyperpolarize____ the membrane potential. - Equilibrium potential: o Na+ =~_+55_mV o K+ = ~_-90_mV o Cl- = ~_-60_mV - 4 mechanisms important for the generation of the resting potential o 1. ____Selective___ permeability of the membrane to ___K+__, which allows this ion to move out of the neuron and keeps other ions from moving into the neuron. o 2. Diffusion along the ____concentration gradient____, which allows K+ to move out of the neuron. o 3. ___Electrostatic____ forces, which oppose the diffusion gradient and brings the system to equilibrium. o 4. The ___Na+/K+_____ pump, which uses energy to move 3 __Na+__ ions out of the neuron and 2 __K+__ ions into the neuron. Lecture 4 – Action Potential - What are graded potentials? What leads to a hyperpolarization vs depolarization? o Graded potentials are the __inputs___ that a neuron receives from other neurons. o ___Hyperpolarization____ is due to an efflux of K+, making the extracellular side of the membrane more positive. This can also be caused by an influx of Cl-. o ___Depolarization___ is due to an influx of Na+ through ____Na+___ channels.  - What are the features of the action potential? o The key features of the action potential are: ▪ It is nondecremental ▪ The ___frequency___ is directly proportional to the stimulus ▪ It is _____all-or-none_______, meaning that when threshold is reached the neuron “fires” and the action potential either occurs or it does not - How is an action potential generated? What are the phases of an AP? o An action potential is generated when local ____depolarization____ of the membrane potential reaches threshold at the axon hillock, opening ___voltage____-gated Na+ channels which causes more Na+ to flow into the neuron and continues to depolarize the neuron until the Na+ channels are inactivated. o The phases of an action potential include: ▪ The initial ___rising____ phase when sodium channels open followed by the opening of potassium channels. ▪ The ____repolarization___ phase when sodium channels close. ▪ The ___hyperpolarization___ phase when potassium channels begin to close. ▪ There is a short ___afterhyperpolarization/afterpotential____ after the final phase of an action potential, where the membrane potential is more negative compared to the resting membrane potential. - Why are refractory periods important? o The __absolute___ refractory period is when it is impossible to initiate another action potential, whereas the ___relative__ refractory period is when it is harder to initiate another action potential but still possible. Refractory periods are important to prevent the ___backward___ movement of action potentials and limit the rate of ___firing___. - What is saltatory conduction? Why is it important? o Myelin restricts the current flow of an action potential to the ___Nodes of Ranvier____ where current flows easily through the channels. Saltatory conduction is a method to ___increase____ transduction speed of an action potential along an axon, allowing myelinated axons to fire at ___higher____ frequencies than non-myelinated axons. Lecture 5 – Synaptic Transmission - Process of “firing” the muscle o Arrival of ___action potential___ at the junction o Release of __neurotransmitter__ from the presynaptic synapse onto the postsynaptic receptors causes the muscle to depolarize o An action potential that then produces muscle __contraction__ - What are the steps that lead to the release of neurotransmitters in the synaptic cleft? o 1. Neurotransmitter is synthesized and stored in ___vesicles_____. o 2. An action potential invades the _____presynaptic terminal__________. o 3. Depolarization of terminal opens voltage-gated ___Ca2+____ channels. o 4. Influx of ___Ca2+____ through channels. o 5. ___Ca2+____ causes vesicles to fuse with the ____membrane____. o 6. Transmitter is released into the _____synaptic cleft______. - What are the 2 major classes of receptors?  o ____Ionotropic_____ receptors which are associated with ligand-activated ion channels. o ____Metabotropic_____ receptors which are associated with signal proteins and G- proteins. - How are post synaptic potentials different from an AP? o Postsynaptic potentials are ____graded_____ potentials, meaning that their size varies. An excitatory postsynaptic potential (EPSP) will ____depolarize____ the postsynaptic neuron, making the neuron more likely to fire. An inhibitory postsynaptic potential (IPSP) will ____hyperpolarize_____ the postsynaptic neuron, making the neuron less likely to fire. o PSPs are ___decremental (decay over time/distance)___, whereas action potentials are nondecremental. o PSPs are fast, whereas action potentials are conducted more ___slowly____ than PSPs. o PSPs are ___passive_____, meaning that no ___energy____ is used, whereas action potentials are active. - What are auto receptors? How do they impact NT release? o Auto receptors are located on the ___presynaptic______ neuron, and act to ___monitor____ the amount of neurotransmitter available for use. - What are the 2 major mechanisms through which an NT is turned off? o ____Reuptake____, where the neurotransmitter is scooped up and recycled o ____Enzymatic degradation______, where the neurotransmitter is broken down by an enzyme