Term
| LTP (Long Term Potentiation) |
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Definition
| An increase in synaptic strength for extended period of time after the stimulation |
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Term
| Heterosynaptic Depression |
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Definition
When the action of a synapse depresses the activity of another axon...
Dependent on the proximity of the other axon and the actual activation of the first axon which results in a Ca2+ mediated removal of receptors of the second synapse. |
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Term
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Definition
Competition, between neurons innervating same target, for ability to evoke a stronger response.
(e.g. Lateral plantar nerve and sural nerve in rat lumbrical muscle as an example) |
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Term
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Definition
Periods of time in which there is a susceptibility to changes/stimuli that will produce long-term effects. If the same experience occurs at a different time-point then the effects may not be as profound.
(e.g. Ocular Dominance, visual deprivation has less of an effect on physiology and anatomy as the cat ages) |
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Term
| Spontaneous Neuronal Activity |
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Definition
Developing neural tissue will spontaneously generate waves of activity that help in the appropriate generation of organization.
(e.g. If cat reared in complete darkness, the ocular dominance columns still form. On the other hand, if cat is treated with TTX then no columns form even if reared in light) |
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Term
| Auditory tuning curves and synapse formation |
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Definition
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Term
| Hubel & Wiesel Experiments |
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Definition
| Set of experiments exploring the impact of visual deprivation on the ocular dominacne of cells in the visual cortex. Normally layer IV will develop into columns of neurons recieving input either from the left or right eye. These then project to integrative cells in later II/III. The activity of these can be measured in order to determine whether they recieve input from both eyes (binocular) or one eye (monocular L/R). |
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Term
| Experience Dependent Modification to Synapses |
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Definition
| Synaptic modifications that occur to according to differences in experience/stimuli. For example int he Hubel and Weisel experiments, monocular deprivation in one eye induced an increase in the recording of monocular dominance histogram and complete elimination of binocular recordings. This is a deviation from the control's whcih is a normal curve. Binocular deprivation restores the normal distribution. |
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Term
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Definition
| Induced "cross-eyed"ness which results in different visual information from each eye. This reduces the number of cortical cells that respond to binocular cues. It essentially causes the integrative cells to align themselves witht he ocular dominance columns that it recieves signals from as opposed to be interspersed and recieve input from mutiple layer IV regions. |
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Term
| Ocular Dominance columns and refinement |
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Definition
| As development progresses, there is refinement in the visual cortex that leads to the generation of ocular dominance colums and also refinementin topogroaphy/postsynaptic compartment in the LGN. |
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Term
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Definition
| A target may be innervated by multiple neurons, this can be detected using a retrograde tracer such as Horse Radish Peroxidase (HRP). With this we can quantify the decrease in projections during development. |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| One axon with multiple branches innervating mutliple neurons. There is a reduction in the branches of this axon. |
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Term
| Refinement of Convergence |
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Definition
| Multiple axons innervating a neuron. There is a reduction in the number of axons. |
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Term
| Refinment of postsynaptic compartment |
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Definition
| One axon innervating a neuron in multiple locations. There is a reduction in the synapses between these two. |
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Term
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Definition
| Changes in response to environmetnal cues leading to refinements in response to stimulation. Can alter physiology with consequences for behavior. |
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