Search results for "Metaplasticity"
showing 3 items of 13 documents
Presynaptic CB1 Receptors Regulate Synaptic Plasticity at Cerebellar Parallel Fiber Synapses
2011
Endocannabinoids are potent regulators of synaptic strength. They are generally thought to modify neurotransmitter release through retrograde activation of presynaptic type 1 cannabinoid receptors (CB1Rs). In the cerebellar cortex, CB1Rs regulate several forms of synaptic plasticity at synapses onto Purkinje cells, including presynaptically expressed short-term plasticity and, somewhat paradoxically, a postsynaptic form of long-term depression (LTD). Here we have generated mice in which CB1Rs were selectively eliminated from cerebellar granule cells, whose axons form parallel fibers. We find that in these mice, endocannabinoid-dependent short-term plasticity is eliminated at parallel fiber…
From different neurophysiological methods to conflicting pathophysiological views in migraine: a critical review of literature.
2014
Abnormal increased cortical responsivity to various types of stimuli plays a major role in migraine pathogenesis. Neurophysiological studies, however, have provided ambiguous findings of either hypo or hyper cortical excitability. This is why the term "dysexcitability" has been recently proposed to indicate a more general dysregulation of cortical excitability. The aims of this review are: (1) to provide existing knowledge and research advances in migraine pathophysiology; (2) to propose a unitary interpretation of apparently conflicting neurophysiological findings. Data of studies conducted in migraine through various evoked potentials techniques and non-invasive brain stimulation methods …
Endocannabinoid Role in Synaptic Plasticity and Learning
2009
Endocannabinoids have recently emerged as versatile modulators of synaptic transmission and can act as retrograde neurotransmitters. As they cannot be stored in synaptic vesicles, endocannabinoid signaling is believed to start ‘on-demand,’ via a stimulus-dependent synthesis from membranous precursors at the postsynaptic site. After synthesis, endocannabinoids bind presynaptically to cannabinoid type 1 (CB1) receptors, leading to a short- or long-term suppression of neurotransmitter release. CB1 receptors are present in a plethora of different synaptic connections in the brain. Electrophysiological and behavioral analyses of mutant mice lacking CB1 receptors and of pharmacologically treated …