COGS 170 Exam Questions and Correct Answers

COGS 170 Exam Questions and Correct Answers Transmembrane Current - ANSWER - Brain waves result from the summation of many simultaneously occurring ionic processes. - Any excitable membrane (spines, dendrites, somas, axons, and axon terminals) and any type of this can contribute to the extracellular field. Brain Waves Evolve From... - ANSWER - The pop. of active cell types, each with distinct physical properties. - The interactions between neurons. - Cognitive of behavioral state of an organism. Rhythms are a Product of... - ANSWER - The neurons that are active and their physiological properties. - The connections between neurons. - The cognitive or behavioral state of an organism. Unique Rhythms - ANSWER - These manifest in each brain region, and they have a relationship to the behavioral and cognitive demands of the organism. Delta - ANSWER - 0.5-4 Hz - SWS Theta - ANSWER - 4-10 Hz - Spatial Navigation. Alpha - ANSWER - 8-13 Hz Beta - ANSWER - 15-30 Hz - Motor movements Gamma - ANSWER - 30-90 Hz - Processing of sensory stimuli. Resonance Freq. - ANSWER - Preferred freq. for certain objects. COGS 170 Exam Questions and Correct Answers Neural Resonance - ANSWER - Property of neurons that enables them to generate spontaneous membrane-voltage oscillations or preferentially respond to inputs delivered at a specific freq. Resonant Freq. - ANSWER - Determined by the physiological properties of the neuron, including: - size of neuron - membrane potential - type and number of receptors/ion channels. Two Conductors - ANSWER - the fluid inside and outside the neuron are separated by an 'insulator' (the membrane), allowing an electric potential difference to exist across the cell membrane. - Often represented as a circuit with a 'capacitor.' Leak Channels - ANSWER - Unlimited ability to allow the passive flow of an ion out of the neuron. Inductors - ANSWER - Channels that oppose changes in membrane voltage. - Certain voltage-gated ion channels can oppose changes in the membrane potential when open. - This is often represented as a circuit with a resistor, capacitor, and inductor or an RLC circuit. - Suppresses slow and fast inputs. Applied Alternating Current - ANSWER - In the brain, this is the equivalent of receiving rhythmic circuit. Membrane Capacitor - ANSWER - Slows down the voltage response to any given current. Ik - ANSWER - Voltage-gated K+ Channel. Tuned - ANSWER - Most neurons are preferentially blank in response to a specific freq. range. COGS 170 Exam Questions and Correct Answers Input impedance - ANSWER - Determines how much a neuron depolarizes in response to an alternating current. Low Pass Filter - ANSWER - Lets low pass through, attenuates high frequencies. High Pass Filter - ANSWER - Lets high pass through, attenuates low frequencies. Impedance - ANSWER - Oscillator cycles, number of cycles per second. - V/I Ohm's Law - ANSWER V = IR Resting Potential - ANSWER - At this period voltage-gated channels are closed. Voltage-Clamp - ANSWER - A current is injected to maintain a desired voltage. Insulator - ANSWER - Two conductors (the fluid inside and outside of the neuron) are separated by this. Positive Allosteric Modulations - ANSWER - Enhance GABA(a) receptor function. Negative Allosteric Modulations - ANSWER - Reduces GABA(a) receptor function. - Smaller amp, higher freq. ING Oscillation - ANSWER - The activation of many mutually connected interneurons. - Frequency is dependent upon: - The after hyperpolarization period of the interneurons. - The time course of the IPSP Pyramidal Neurons - ANSWER - Project outside a region and usually excite other neurons. - These and interneurons both participate in synchronous gamma after titanic stimulation. - Can have a long after hyperpolarization causing them to skip gamma cycles, while interneurons continue to fire at gamma