Neuroscience Glossary G-L Exam 2
Terms in this set (86)
An amino acid that is the major inhibitory
neurotransmitter in the CNS
A smaller neuron whose cell body is found in the ventral horn of the spinal cord. Innervates intrafusal muscle fibers of the muscle spindle and plays a role in muscle tone
Collections of neuron cell bodies lying outside the CNS, usually with a common function
An ion channel that functionally links or connects two adjacent cells, also creates an electrical
The ability of channels to be opened or closed either by membrane potential (voltage-gated, voltage-dependent, voltage-sensitive) or by the arrival of a neurotransmitter or other chemical (ligand-gated), or by mechanical stretch
Anterior bent end of corpus callosum.
Internal genu of facial nerve
(facial motor fibers loop around or bend around, the abducens nucleus at the level of the ponto-medullary junction). Bend in the internal capsule where the two sides are most closely apposed, more obvious in horizontal slices. The genu
of the internal capsule is one of the anatomical hallmarks of the region called "middle of the brain".
Non-neuronal cells within the CNS. Glia are much more numerous than neurons, and consist of three major types: oligodendroglia, astrocytes, and microglia. These cells play roles in support, myelination, balancing extracellular concentrations and immune function.
A nuclear mass in the basal ganglia of the CNS. Forms the medial part of lentiform nucleus of the corpus striatum. Involved in the motor system. Has and internal and an external segment.
An amino acid that is the major excitatory neurotransmitter in the central nervous system. Also heavily involved in learning and memory.
Inhibitory cells of cerebellar cortex, which are activated by 1) mossy fibers and climbing fibers to provide feed-forward inhibition to granule cells, and 2) parallel fibers to provide recurrent inhibition to granule cells. Use the neurotransmitter GABA.
golgi tendon organ
Specialized sensory structure located in the tendons of striated muscle. Involved in sensing the strain (tension) on a muscle and prevents its damage due to overcontraction.
(=long and think, such as legs)
Fasciculus gracilis (long thin tract) of the spinal cord and medulla; nucleus gracilis (gracile nucleus)
and gracile tubercle of the medulla.
Used to denote small neurons, such as granule cells of cerebellar cortex and stellate cells of cerebral cortex. Hence granular layers of both cortices.
Glutamate-releasing axons are the source of parallel fibers in cerebellar cortex. Receive inputs from mossy fibers and form an activated strip along the cerebellar folia.
gray (grey) matter
Brain tissue predominantly composed of neuron cell bodies such as cerebral cortex, basal ganglia and thalamus. Actually looks pinkish-gray when you cut open a fresh brain.
A distinctive structure at the growing end of most axons. It is the site where new material is added to the axon as it grows and searches for its target.
Folds of gray matter forming the cerebral hemispheres; gyri are the ridges (bumps).
A small swelling (containing habenular nuclei) in the epithalamus, adjacent to the posterior end of the roof of the third ventricle.
A nonassociative learning form leading to decreased behavioral responses to repeated stimulation.
A synapse that that increases in strength when both the presynaptic and postsynaptic neurons are active at the same time. "Neurons that fire together, wire together".
A violent form of motor restlessness involving one side of the body, caused by a destructive lesion involving the subthalamic nucleus. There are ballistic movements (e.g. appears as though the patient is trying to throw an extremity) on one half (hemi) of the body.
Paralysis of one side of the body. Could be due to a blow to the head or stroke. May be incomplete.
A stroke caused by a ruptured blood vessel and characterized by a hemorrhage (bleeding) within or surrounding the brain.
Virus infection of primary sensory neurons; causes a painful rash in skin or mucous membranes supplied by the ganglion.
A three-layered cortical area in the temporal lobe. This area is involved in declarative memory (memory for events) and spatial memory. (Shaped somewhat like a sea horse). Functions like a computer "cache" memory.
A set of equations that describe how action potentials in neurons are initiated and propagated by taking account of changes in conductance of voltage-sensitive sodium and potassium channels.
a tendency toward stability in the internal environment of the organism
same side or structure
The horizontal plane is horizontal with the person in the anatomical position (standing erect and at rest). It runs anterior (front) to posterior (back); medial to lateral (also left to right).
A compound secreted into the blood that exercises a specific physiological function elsewhere in the body.
an inherited movement disorder characterized by dance-like movements
Excessive accumulation of cerebrospinal fluid, e.g. within the brain ventrical system. In neonates it causes the head to enlarge
Abnormal loudness of perceived sounds, due to paralysis of middle ear muscles.
Change in membrane potential in the negative direction from the resting membrane potential. This is usually associated with inhibition of the cell.
elevated blood pressure
A condition in which a reflex is more vigorous than expected. Diagnostic of a lesion in any central nervous system pathway that influences the reflex arc ("upper motorneuron lesion"), especially a lesion within the corticospinal tract.
The pituitary gland, including the pituitary stalk and the median eminence. Adenohypophysis (anterior pituitary), neurohypophysis (posterior pituitary).
A condition in which a reflex is less vigorous than expected.
A region of the diencephalon that serves as the main controlling center of the autonomic nervous system. It influences such functions as reproduction, endocrine systems, cardiovascular control, temperature regulation, food intake, etc.
Often mistaken for stroke, hypoxia refers to a lack of oxygen, in contrast to the lack of blood flow caused by stroke. Although the symptoms are similar to stroke, hypoxia is characterized by gait and speech disturbances, tremors and weakness. The brain may suffer from hypoxia even if blood flow and blood pressure are normal. Causes include chronic pulmonary disease, pulmonary emboli, alveolar hypotension, anemia and carbon monoxide poisoning.
A phase of memory that is extremely short-lived, with information stored for a few seconds or minutes. Also known as short-term and working memory.
"Closing" of a voltage-gated sodium ion channel that contributes to the refractory periods. The conformation of the protein channels is such that a return of the plasma membrane to values close to the resting membrane potential and a little time are needed for channels to come out of the inactivated state and return to the resting state .
Lack of control over excretory functions (urination, bowels).
In embryology, the action of one population of cells upon the development of another population of nearby cells.
The immediate area of brain cell death caused by a stroke. When the brain cells in the
infarct die, they release chemicals that set off a chain reaction that endangers brain cells in a larger surrounding area, known as the penumbra
Regional death of tissue due to loss of blood supply. (e.g. myocardial infarction, cerebellar infarct, also pertains to stroke).
Infundibular stem of the pituitary gland. (Narrow, funnel part of hypophysis).
In reference to neurons, it is a synaptic message that prevents the recipient cell from firing. Usually the result of IPSPs.
inhibitory postsynaptic potential (IPSP)
Neurotransmitter-induced postsynaptic potential making the postsynaptic neuron less likely to fire action potentials.
For an axon of a neuron to connect synaptically with some other neuron or cell (muscle or gland).
Cerebral cortex concealed from surface view and lying at the bottom of the lateral sulcus (fissure). Also called the island of Reil.
Combination of incoming inhibitory and excitatory signals in a neuron or neuronal unit, which determines its output. Neuronal processing.
A neuron with axons that only project locally. In the cerebral cortex many of these appear to be inhibitory.
One of the sensory end organs within viscera. Gives the CNS information about the interior of the body.
The inside of a cell. An aqueous environment.
A lesion "stroke" caused by bleeding within the brain.
Specialized, smaller muscle fibers located within muscle spindles. Are involved in establishing and sensing muscle tone. Innervated by gamma motor neurons to correct their bias (length) during gross muscle contraction and relaxation.
A charged atom, either missing electrons or with too many electrons. The most important ions in the nervous system are Na+,K+,Cl-,Ca++. The superscript tells you what type of charge it is and whether it is monovalent (one, +) or divalent (two, ++).
An protein that lies in the cell membrane (integral membrane protein) that has a hole that allows ions to pass from one side of the membrane to the other. Most of these ion channels are selective, only allowing passage of certain ions and not letting others through. Usually gated.
on the same side of the midline or body, opposite of contralateral
A circular diaphragm that contains the muscles which alter the amount of light that enters the eye by dilating or constricting the pupil. It has an opening in its center. The exterior iris is colored (brown, blue, green, etc.).
The condition of tissue that is not adequately perfused with oxygenated blood.
Cerebral cortex having six layers (neocortex).
The sense of perception of movement (conscious proprioception). The appreciation of body movement and its position in space.
The appreciation of body movement and its position in space. Often used interchangeably with conscious proprioception, though use of the term "kinesthesia" can place a greater emphasis on motion
Areas of cerebral cortex containing large (well-developed) numbers of small (granular, layer 4) neurons; typical of sensory areas of cortex, such as primary sensory Brodmann area 17 of the visual cortex, Brodmann areas 1-3 of the somatic sensory cortex, and Brodmann area 41 of the auditory cortex.
A disease associated with chronic alcoholism, resulting from deficiency of vitamin B1. Patients sustain damage to part of the thalamus and cerebellum. Symptoms include inflammation of nerves, delirium, insomnia, hallucinations and amnesia.
The vestibule, semicircular canals and cochlea, which are entombed in the petrous part of the
Towards the side and away from the midline. For example, the ears are lateral to the brain.
lateral geniculate nucleus (LGN) (or lateral geniculate body)
An area of the thalamus that relays visual information from the retina to other brain sites.
Acquisition of new info/knowledge through experience leading to a permanent change mediated by synaptic plasticity.
The left half of the brain. Senses stimuli from and controls actions of the right side of the body and also processes information for analytic abilities, such as calculating, speaking and writing. The cerebellum also has hemispheres but the unspecified term infers the cerebrum.
Used to designate a bundle of nerve fibers in the central nervous system (e.g., medial lemniscus and lateral lemniscus).
Lens-shaped. Lentiform nuclei; components of the corpus striatum comprised of the putamen and globus pallidus. Also called lenticular nuclei.
the arachnoid and pia mater
Applied to many abnormalities. In the nervous system, lesions may be destructive (infarct, traumatic injury from bullet or knife or blow, hemorrhage or tumor), degenerative (Alzheimer's, Parkinson's), over-stimulation of neurons (as in epilepsy, seizures), cause synaptic dysfunction (Myasthenia Gravis, poisoning), infectious in nature (meningitis, parasites), or even congenital.
An ion channel which opens and closes depending on the arrival of some chemical (ligand) which binds or modulates the channel protein - the ligand is usually a neurotransmitter, hormone or second messenger.
C-shaped configuration of cortex on the medial surface of the cerebral hemisphere, consisting of the septal area and the cingulate and parahippocampal gyri, with probable pain-, emotion- and emotional learning-related functions.
The limbic lobe, hippocampal formation, and portions of the diencephalon (esp. the mammillary bodies and certain thalamic nuclei). Also, a set of interconnected brain structures that may be involved in emotion and/or emotional learning (see Papez circuit). This group of brain structures often includes the amygdala, septum and basal ganglia. Overall, this system functions in the regulation of emotions, memory and certain aspects of movement (esp. sexual behaviors).
In the eye; Area of the junction of the cornea and sclera which rings the edge of the cornea.
Part of the architecture of cell membranes in mammals. Can be understood by thinking of a soap bubble. Soaps are amphoteric: one end is fatty and the other end is ionic. This allows them to clean: One end sticks to grease (hydrophobic = hates water) and the other end sticks to water (hydrophilic = loves water). In a soap bubble all the hydrophilic ends stick out and the hydrophobic ends point inward and interact to form a membrane. A lipid bilayer is like 2 soap bubbles one inside the other with the inner one's hydrophilic heads sticking in to the cytoplasm.
locus coeruleus (or ceruleus)
A small dark spot on each side of the floor of the fourth ventricle; marks the position of a group of nerve cells that contain melanin pigment. They form a nucleus in the reticular formation functioning as a diffuse modulatory network for Norepinephrine.
long-term depression (LTD)
A persistent or long-lasting depression of synaptic transmission strength or efficiency found in many brain areas but especially the hippocampus and cerebellum. Provides a way to undo long-term potentiation. Apparently, it is the major mechanism at the parallel fiber to the Purkinje cell synapse of the cerebellum helping form motor patterns.
The final phase of memory in which information storage may last from hours to a lifetime.
long-term potentiation (LTP)
A persistent strengthening of synaptic strength or efficiency; May be the neural analogue of the Hebb synapse and one of the mechanisms underlying learning and memory. NMDA receptors are usually involved in this process. May be thought of as the opposite of long-term depression. Some dispute about its prevalence in the cerebellum.
lower motor neurons (LMNs)
Motor neurons connecting the brainstem and spinal cord to muscle fibers, bringing the nerve impulses from the upper motor neurons out to the muscles. A lower motor neuron's axon terminates on an effector (muscle or gland).