Action Potential
A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation.
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| Term | Definition |
|---|---|
| Action Potential | A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation. |
| Axon | Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron. |
| Brain Stem | The “trunk” of the brain comprised of the medulla, pons, midbrain, and diencephalon. |
| Broca’s Area | An area in the frontal lobe of the left hemisphere. Implicated in language production. |
| Central Nervous System | The portion of the nervous system that includes the brain and spinal cord. |
| Cerebellum | The distinctive structure at the back of the brain, Latin for “small brain.” |
| Cerebrum | Usually refers to the cerebral cortex and associated white matter, but in some texts includes the subcortical structures. |
| Contralateral | Literally “opposite side”; used to refer to the fact that the two hemispheres of the brain process sensory information and motor commands for the opposite side of the body. |
| Corpus Callosum | The thick bundle of nerve cells that connect the two hemispheres of the brain and allow them to communicate. |
| Dendrite | Part of a neuron that extends away from the cell body and is the main input to the neuron. |
| Diffuse Optical Imaging (DOI) | A neuroimaging technique that infers brain activity by measuring changes in light as it is passed through the skull and surface of the brain. |
| Electroencephalography (EEG) | A neuroimaging technique that measures electrical brain activity via multiple electrodes on the scalp. |
| Frontal Lobe | The front most (anterior) part of the cerebrum; responsible for motor output and planning, language, judgment, and decision-making. |
| Functional Magnetic Resonance Imaging (fMRI) | A neuroimaging technique that infers brain activity by measuring changes in oxygen levels in the blood. |
| Limbic System | Includes the subcortical structures of the amygdala and hippocampal formation as well as some cortical structures; responsible for aversion and gratification. |
| Myelin Sheath | Fatty tissue that insulates the axons of the neurons; myelin is necessary for normal conduction of electrical impulses among neurons. |
| Nervous System | The body’s network for electrochemical communication. This system includes all the nerve cells in the body. |
| Neuron | Individual brain cells. |
| Neurotransmitter | Chemical substances released by the presynaptic terminal button that act on the postsynaptic cell. |
| Occipital Lobe | The back most (posterior) part of the cerebrum; involved in vision. |
| Parietal Lobe | The part of the cerebrum between the frontal and occipital lobes; involved in bodily sensations, visual attention, and integrating the senses. |
| Peripheral Nervous System | All of the nerve cells that connect the central nervous system to all the other parts of the body. |
| Positron Emission Tomography (PET) | A neuroimaging technique that measures brain activity by detecting the presence of a radioactive substance in the brain that is initially injected into the bloodstream and then pulled in by active brain tissue. |
| Soma | Cell body of a neuron that contains the nucleus and genetic information, and directs protein synthesis. |
| Spatial Resolution | Refers to how small the elements of an image are; in neuroscience, how small of a structure in the brain can be imaged. |
| Split-brain | A patient who has had most or all of his or her corpus callosum severed. |
| Synapse | Junction between the presynaptic terminal button of one neuron and the dendrite, axon, or soma of another postsynaptic neuron. |
| Synaptic Gap | Also known as the synaptic cleft; the small space between the presynaptic terminal button and the postsynaptic dendritic spine, axon, or soma. |
| Temporal Lobe | The part of the cerebrum in front of the occipital lobe and below the lateral fissure; involved in vision, auditory processing, memory, and integrating vision and audition. |
| Temporal Resolution | Refers to how small a unit of time can be measured; in neuroscience, how precisely in time a process can be measured in the brain. |