Single spine stimulation by two-photon activation (uncaging) of glutamate has revealed that the uncaging-evoked AMPA-R current through the stimulated spine is strongly correlated with spine head size, which supports the hypothesis that dendritic spine size is a key determinant of synaptic efficacy
. (14) Crucially, dendritic spines are highly dynamic and undergo structural enlargement and shrinkage (Fig.
[28.] Markram H, Lubke J, Frotscher M, Sakmann B (1997) Regulation of synaptic efficacy
by coincidence of postsynaptic APs and EPSPs.
Long-term potentiation (LTP), a long-lasting increase in synaptic efficacy
, is widely accepted as a basic mechanism for learning and memory.
To bring the ultimate goal of developing a brain-machine-spinal-cord interface (BMSI) device for functional recovery after SCI to fruition, this project will establish the appropriate parameters for stimulating the spinal cord and increasing synaptic efficacy
using brain activity after SCI.
Further, monocarboxylates [38-41] and KBs [39, 41] can maintain synaptic efficacy
and plasticity, the basis of cognitive function.
On the other hand, dysfunction of hippocampal synaptic efficacy
is known to be related to cognitive impairment in AD [7, 8] as well as in aging [9-11], and synaptic efficacy
has protective effects against AD [12,13].
"In our model, even weak and spatially localized input from the hippocampus influenced the spatiotemporal pattern of slow oscillations and led to a persistent change of synaptic efficacy
between neurons," Wei said.
In the striatum, the net effect of chronic ethanol has been less well studied, but the work to date indicates that ethanol exposure brings about an LTP-like enhancement of synaptic efficacy
at glutamatergic synapses that transmit signals to striatal MSNs.
According to the calcium control hypothesis, basal levels of calcium concentration do not lead to any changes in synaptic efficacy
but modest and high levels of calcium concentration lead to LTP and excitotoxity stage respectively .
Increases in phosphorylation of the extracellular regulated protein kinase (ERK), a subfamily of MAPKs alter synaptic efficacy
and learning and memory.
It has been demonstrated that the minor alteration in synaptic efficacy
happened earlier than the anatomical abnormality in neurodegenerative disorders [23,24].
This property, known as synaptic efficacy
, can be adjusted by the brain as part of the process of encoding information.