Neuroscience 6e Chapter 1

action potential - correct answer The electrical signal generated and conducted along axons (or muscle fibers) by which information is conveyed from one place to another in the NS (or within muscle fibers) afferent neurons (sensory neurons) - correct answer neurons or axons that conduct action potentials from the periphery to the CNS anterograde - correct answer signals or impulses that travel forward, e.g., from the cell body to the axon terminal, from the presynaptic terminal to the postsynaptic cell, or from the CNS to the periphery. associational systems - correct answer neural cells circuits that are not part of the relatively defined sensory (input) and motor (output) systems; they mediate the most complex and least well-defined brain functions that require the integration or association of signals from multiple sensory and/or motor systems. astrocytes - correct answer the most complex of the three major classes of glial cells; found in the gray matter of the CNS because is closely related to neuronal bodies, dendrites, and synapses. (( 1. help to maintain and regulate an appropriate chemical environment for neuronal signaling--ionic balance of extracellular fluids 2) also involved in the formation of the BBB and brain-ependymal (ventricular) barrier 3) the secretion of substances that influence the construction of new synaptic connections and circuits, and the proliferation of new cells in the adult brain that retain characteristics of stem cells 4) they remove and process neurotransmitters from synaptic clefts 5) assist in the formation of new synaptic clefts. 6) contribute to the formation of scars in the necrotic neural tissue following injury)) autonomic ganglia - correct answer collections of autonomic motor neurons outside the CNS that innervate visceral smooth muscles, cardiac muscle, and glands. axon - correct answer the neuronal process (typically, much longer than any dendrite) that conveys the action potential from the neuron body to its terminal. Usually surrounded by a myelin sheath. They may have branches that can activate other nearby cells through local connections, but in general they are not as elaborate as those made by dendrites. bacteriorhodopsin - correct answer a protein that, in response to light of the proper wavelength, acts as a proton pump transporting protons from inside the cell to outside ; in its native host, the resulting proton gradient is subsequently converted into chemical energy; when engineered into a neuron for optogenetics, it hyperpolarizes the neuron when exposed to the light. blood oxygenation level-dependent (BOLD) - correct answer endogenous signals reflecting the oxygenation of hemoglobin in blood that are modulated by the changes in the local level of neural activity (for example when neural activity in a local brain region increases, more oxygen is consumed and within seconds the local microvasculature responds by increasing the flow of oxygen-rich blood to the active region, thus constituting a BOLD signal that may be detected by fMRI.) neurons - correct answer also called nerve cells. Cells specialized for the generation, conduction, and transmission of electrical signals in the NS. Most neurons are distinguished by their specialization for long-distance electrical signaling and intercellular communication. most salient aspect of the branching for typical neurons are the presence of an axon and the elaborate arborization of dendrites that arise from the neuronal cell body. tracts - correct answer Bundles of fasciculated axons in the CNS that are gathered into compact structures and typically share a common origin and termination; more or less analogous to nerves in the periphery. functional magnetic resonance imaging (fMRI) - correct answer magnetic resonance imaging that detects changes in the blood and therefore identifies regions of the brain that are particularly active during a given time. spinal cord - correct answer the caudal (post cranial) portion of the CNS that extends from the lower end of the brainstem (the medulla) to the cauda equina; mediates the transmission of both afferent and efferent neural signals between the CNS and the body. event related potential (ERP) - correct answer averaged EEG recording measuring time-locked brain responses to repeated presentations of the stimulations of a stimulus or repeated execution of a motor task. peripheral nervous system (PNS) - correct answer all nerves and neurons that lie outside the brain and spinal cord. electrical synapse - correct answer synapses that transmit information via the direct flow of electrical current at gap junctions. electroencephalography (EEG) - correct answer the study of electrical potentials generated in the brain recorded from electrodes placed on the scalp. somatic motor division - correct answer the components of the motor system that support skeletal movements mediated by the contraction of skeletal muscles that are derived from embryonic somites or somitomeres. commissures - correct answer axon tracts that cross the midline of the brain or spinal cord. neurotransmitters - correct answer substances released by synaptic terminals for the purpose of transmitting information from one cell (presynaptic cell) to another (postsynaptic cell). synaptic cleft - correct answer the space that separates pre and postsynaptic neurons at chemical synapses. interneurons - correct answer technically, a neuron in the pathway between primary sensory and primary effector neurons; more generally, a neuron whose relatively short axons branch locally to innervate other neurons. Also known as local circuit neuron. (project distance of 100s of microns, many ar excitatory, most are inhibitory) Schwann cells - correct answer glial cells in the PNS that lay down myelin, which facilitates the efficient generation and rapid conduction of action potentials; also facilitates axon regeneration In the damaged nerves (named after 19th century anatomist and physiologist Theodor Schwann) convergence - correct answer innervation of a target cell by axons from more than one neuron. In vision, it refers specifically to the convergence of both rod and cone photoreceptor cells onto retinal ganglion cells. nerves - correct answer a collection of peripheral axons that are bundle together and travel a common route. columns - correct answer term used to describe an elongated gray matter structure (e.g., the motor neuronal pool in the ventral horn of the spinal cord that innervates a muscle) or a subdivision of white matter (e.g., a region of white matter in the spinal cord containing long axon tracts). cranial nerve ganglia - correct answer the sensory ganglia associated with the cranial nerves; these correspond to the dorsal root ganglia of the segmental nerves of the spinal cord. pneumoencephalography - correct answer an x-ray based means for brain imaging involving the displacement of cerebrospinal fluid by injection of air into the subarachnoid space to increase signal contrast. electrophysiological recording - correct answer measure of the electrical activity across the membrane of a nerve cell by use of electrodes. retrograde - correct answer signals or impulses that travel "backward," e.g., from the axon terminal toward the cell body, or from the postsynaptic cell to the presynaptic terminal, or from the periphery to the CNS. genetic analysis - correct answer the analysis of the relationship between single genes and the the phenotypes to which each gene contributes.