Touch and Proprioception
Receptors specialized to sense mechanical forces.
Mechanoreceptors
The coiled structure in the inner ear where vibrations caused by sound are transduced into neural impulses.
cochlea
Laminated, superficial gray matter of the cerebellum.
cerebellar cortex
Restricted developmental periods during which the nervous system is particularly sensitive to the effects of experience.
critical period
Fibers of skeletal muscles that generate primary biomechanical force during muscle contraction; a term that distinguishes ordinary muscle fibers from the specialized intrafusal fibers associated with muscle spindles.
extrafusal fibers
Systematic representation of sound frequency along the length of the cochlea.
Tonotopy
Subcortical nuclei at the base of the cerebellum that give rise to output from the cerebellum to the thalamus and brainstem.
deep cerebellar nuclei
The idea that when pre- and postsynaptic neurons fire action potentials at the same time, the synaptic association between those cells strengthens.
Hebb's postulate
Define "cortical magnification" and give at least one example.
The amount of neural tissue (e.g., cortical area) devoted to each area of the sensory surface is not uniform but reflects the density of receptors and sensory axons that supply the downstream target.
Site where the middle ear ossicles transfer vibrational energy to the cochlea.
oval window
Division of the basal ganglia that receives input from the striatum and provides inhibitory (GABAergic) output to the thalamus and brainstem.
pallidum
Name and describe the three basic requirements for evolution by natural selection.
"Adjacent or neighbouring portions of physical space or sensory receptor surfaces project onto adjacent or neighbouring portions of neural tissue."
Topographic organisation
The actin-rich processes that form the hair bundle extending from the apical surface of the hair cell; site of mechanotransduction.
Stereocilia
A pathological inability to make coordinated movements, associated with lesions or congenital malformation of the cerebellum.
cerebellar ataxia
Local proliferation of glial precursors and extensive growth of processes from existing glia within or around the site of a brain injury; it prevents axonal regrowth.
Glial scarring
Highly specialized mechanosensory organs found in most skeletal muscles; provide proprioceptive information about muscle tension.
Golgi tendons
A structure in the auditory brainstem that aids in sound localization by computing interaural time differences.
medial superior olive (MSO)
Division of the basal ganglia involved in saccade generation by dis-inhibition.
Caudate nucleus
After reaching their destination in a given region of the brain or spinal cord, neuroblasts form distinct cell types. _______ involves turning off some genes and turning on others by the action of transcription factors via local signals.
______ is the subsequent ensheathing of axons in lipid-rich substances.
Once precursor cells have migrated to their destinations and transformed into neurons, they send out axons and dendrites. This process is called ______.
Differentiation, myelination, synaptogenesis