The invention provides molecular systems for inducible and reversible inactivation of synaptic transmission. These systems can be used for studying neuronal networks and for treating conditions involving abnormally high neuronal activity or excitotoxic da...
National Technical Information Service (NTIS)
Since the aspect of neural function conspicuously vulnerable to chemicals and drugs is synaptic transmission, drug modification of conditioning is instructively viewed in the light of drug modification of synaptic transmission. The nature of psychotropic ...
... Title : Changes in Synaptic Transmission Following Bath Application or Microinjection of Phospholipase A2 Neurotoxins in Paired Cholinergic ...
DTIC Science & Technology
... PARASYMPATHOLYTIC AGENTS, NEUROMUSCULAR TRANSMISSION, NERVE CELLS, DRUGS, FROGS, AUTONOMIC NERVOUS SYSTEM. ...
There is mounting evidence showing that the structural and molecular organization of synaptic connections is affected both in human patients and in animal models of neurological and psychiatric diseases. As a consequence of these experimental observations, it has been introduced the concept of synapsopathies, a notion describing brain disorders of synaptic ...
PubMed Central
Filamentous tau inclusions are hallmarks of Alzheimer's disease and related neurodegenerative tauopathies, but the molecular mechanisms involved in tau-mediated changes in neuronal function and their possible effects on synaptic transmission are unknown. We have evaluated the effects of human tau protein injected directly into the presynaptic terminal axon ...
PubMed
... Abstract : The project on synaptic transmission in the squid giant synapse was supported from years 1989 to 1994, and was discontinued due to a ...
The synaptic mechanisms in sympathetic ganglia and the ways in which low doses of atropine may act in the body were investigated. The results obtained support the contention that there is an adrenergic (inhibitory) synaptic mechanism operating in ganglia,...
Increasing evidence suggests that the accumulation of amyloid beta (A?) in synapses and synaptic mitochondria causes synaptic mitochondrial failure and synaptic degeneration in Alzheimer's disease (AD). The purpose of this study was to better understand the effects of A? in mitochondrial activity and synaptic ...
Dendritic spines are small protrusions from neuronal dendrites that form the postsynaptic component of most excitatory synapses in the brain. They play critical roles in synaptic transmission and plasticity. Recent advances in imaging and molecular technologies reveal that spines are complex, dynamic structures that contain a dense array of cytoskeletal, ...
NSDL National Science Digital Library
This article describes an exercise that illustrates the temperature sensitivity of synaptic transmission. The temperature dependence of synaptic transmission is demonstrated by cooling the larval Drosophila melanogaster preparation and recording excitatory junction potentials. Vesicle recycling is explored by ...
In Huntington's disease (HD), the expansion of polyglutamine (polyQ) repeats at the N terminus of the ubiquitous protein huntingtin (htt) leads to neurodegeneration in specific brain areas. Neurons degenerating in HD develop synaptic dysfunctions. However, it is unknown whether mutant htt impacts synaptic function in general. To investigate that, we have ...
Neurotransmitter release is essential for chemical synaptic transmission, and the efficacy of synaptic transmission depends on how much transmitter is released from discrete sites in the axon terminal called active zones. The number and structural organiz...
... Keywords: Synapse; Plasticity; Phosphorylation; Fatty acids; Lontophopersis. Descriptors : *SYNAPSE, *NERVE TRANSMISSION ...
Sensory experience, and the lack thereof, can alter the function of excitatory synapses in the primary sensory cortices. Recent evidence suggests that changes in sensory experience can regulate the synaptic level of Ca2+-permeable AMPA receptors (CP-AMPARs). However, the molecular mechanisms underlying such a process have not been determined. We found ...
synaptic potentials in the piriform cortex. J. Neurophysiol. 81: 2103�2118, 1999. Intracellular recordings from pyramidal neurons in brain slice preparations of the piriform cortex were used to test results from a computational model about the effects of cholinergic agonists on inhibitory synaptic potentials induced by stimulation of afferent fibers in ...
E-print Network
It is clear that de novo protein synthesis has an important function in synaptic transmission and plasticity. A substantial amount of work has shown that mRNA translation in the hippocampus is spatially controlled and that dendritic protein synthesis is required for different forms of long-term synaptic plasticity. More recently, ...
Neuroligins (NLs) are a family of neural cell-adhesion molecules that are involved in excitatory/inhibitory synapse specification. Multiple members of the NL family (including NL1) and their binding partners have been linked to cases of human autism and mental retardation. We have now characterized NL1 deficient mice in autism and mental retardation-relevant behavioral tasks. NL1 KO mice display ...
The septin family of GTPases, first identified for their roles in cell division, are also expressed in postmitotic tissues. SEPT3 (G-septin) and SEPT5 (CDCrel-1) are highly expressed in neurons, enriched in presynaptic terminals, and associated with synaptic vesicles. These characteristics suggest that SEPT3 or SEPT5 might be important for synapse formation, maturation, or ...
Effect of glycine on synaptic transmission at the third order giant synapse of the squids of the third order giant synapses of the squids Alloteuthis subulata and Loligo vulgaris. Synaptically mechanism to suppress or potentiate synaptic transmission in the squid giant synapse. q 2002 Elsevier
Studies examining the etiology of motoneuron diseases usually focus on motoneuron death as the defining pathophysiology of the disease. However, impaired neuromuscular transmission and synapse withdrawal often precede cell death, raising the possibility that abnormalities in synaptic function contribute to disease onset. Although ...
Elevated expression of neuroinflammatory factors in the central nervous system (CNS) contributes to the cognitive impairment in CNS disorders such as injury, disease and neurodegenerative disorders. However, information on the role of specific neuroimmune factors in normal and abnormal CNS function is limited. In this study, we investigated the effects of chronic exposure to ...
Exposure of newborn rats to antiepileptics such as barbiturates has long-lasting detrimental effects on the hippocampus and hippocampus-dependent behavior. However, the long-term consequences of neonatal administration with barbiturates on the hippocampal synaptic plasticity remain unresolved. In this study, we investigated the long-lasting effects of a neonatal administration ...
AMPA glutamatergic receptors (AMPAR) mediate the majority of fast excitatory synaptic transmission in mature neurons. In contrast, a number of developing synapses do not express AMPARs; these are gradually acquired in an activity-driven manner during the first week of life in rats, which is equivalent to the third trimester of human pregnancy. Neuronal ...
Clinical and experimental evidence indicates that exposure to alcohol in utero is associated with altered immune capacity. The mechanisms underlying such abnormalities are not clear. However, the suggestion that reciprocal interactions between the immune and the nervous systems are necessary for a competent immune response may be relevant. This work examined the consequences ...
We herein review the histochemical findings and fine structural changes of motor endplates associated with diseases causing neuromuscular transmission abnormalities. In anti-acetylcholine receptor (AChR) antibody-positive myasthenia gravis (MG), type 2 fiber atrophy is observed, and the motor endplates show a reduction in the nerve terminal area, ...
One fundamental unanswered question in the field of polyglutamine diseases concerns the pathophysiology of neuronal dysfunction. Is there dysfunction in a specific neuronal population or circuit initially that contributes the onset of behavioral abnormalities? This study used a systems-level approach to investigate the functional integrity of the excitatory cerebellar cortical ...
Calpains are calcium-dependent enzymes that determine the fate of proteins through regulated proteolytic activity. Calpains have been linked to the modulation of memory and are key to the pathogenesis of Alzheimer disease (AD). When abnormally activated, calpains can also initiate degradation of proteins essential for neuronal survival. Here we show that calpain inhibition ...
Opioids classically regulate the excitability of neurons by suppressing synaptic GABA release from inhibitory neurons. Here, we report a role for opioids in modulating excitatory synaptic transmission. By activating ubiquitously clustered ?-opioid receptor (MOR) in excitatory synapses, morphine caused collapse of preexisting dendritic ...
We evaluated various forms of hippocampus-dependent learning and memory, and hippocampal synaptic plasticity in THY-Tau22 transgenic mice, a murine tauopathy model that expresses double-mutated 4-repeat human tau, and shows neuropathological tau hyperphosphorylation and aggregation throughout the brain. Focussing on hippocampus, immunohistochemical studies in aged THY-Tau22 ...
A hallmark feature of Alzheimer�s disease pathology is the presence of neurofibrillary tangles (NFTs), which are intracellular aggregates of conformationally abnormal and hyperphosphorylated tau. The presence of NFTs in the forebrain is associated with impairments of cognitive function, supporting a central role for tau in dementia. The significance of the accumulation of ...
Short communication Short-term depression of synaptic transmission from rat lateral geniculate-term synaptic plasticity, paired-pulse depression (PPD) and frequency depression, were prominent in the adult reduced the short-term synaptic depression. When NMDA or AMPA/kainate receptors were blocked, no obvious
Although many genetic disorders are characterized by cognitive failure during development, there is little insight into the neurobiological basis for the abnormalities. Down syndrome (DS), a disorder caused by the presence of three copies of chromosome 21 (trisomy 21), is characterized by impairments in learning and memory attributable to dysfunction of the hippocampus. We ...
The chronic accumulation of amyloid beta (A?) peptides is thought to underlie much of the pathology of Alzheimer's disease (AD), and transgenic mice overexpressing A? show both behavioral defects and impairments in hippocampal synaptic transmission. In the present study, we examined excitatory transmission at the Schaffer collateral ...
Bilateral alternation of muscle contractions requires reciprocal inhibition between the two sides of the hindbrain and spinal cord, and disruption of this inhibition should lead to simultaneous activation of bilateral muscles. At 1 day after fertilization, wild-type zebrafish respond to mechanosensory stimulation with multiple fast alternating trunk contractions, whereas bandoneon (beo) mutants ...
The present report reviews progress over a period of 28 months in studies concerning the effects of organophosphates and anticholinergic agents on Ca++ -dependent processes in synaptic transmission. Processes which were studied include voltage-dependent a...
Autosomal dominant forms of familial Alzheimer�s disease (FAD) are associated with increased production of the amyloid ? peptide, A?42, which is derived from the amyloid protein precursor (APP). In FAD, as well as in sporadic forms of the illness, A? peptides accumulate abnormally in the brain in the form of amyloid plaques. Here, we show that overexpression of ...
... B and C fibers in the preganglionic nerve; this is ... of the frog to certain autonomic blocking agents ... reduction in resting potential, due to damage to the ...
... Excitation, Synaptic Transmission and Muscle Contraction. ... or striated muscle cells, endocrine ... EXCHANGE, CHANNELS, MUSCLES, PROTEINS ...
Professor Graham Collingridge describes the process of long-term depression (LTD), a way of decreasing the efficiency of synaptic transmission.
... role of excitatory and inhibitory amino acids (ie, glutamate and GABA) in synaptic transmission, (2) the membrane properties of SCN neurons, and ...
... produced a concentration-dependent depression of the ... CENTRAL NERVOUS SYSTEM, AMINO ACIDS, CHANNELS, NEUROTRANSMITTERS. ...
by a group of lively NIH postdoctoral fellows. We are interested in multiple aspects of brain function, including the cellular basis of synaptic transmission and plasticity,...
Science.gov Websites
... weakness of the heart muscle ( cardiomyopathy ) and abnormal transmission of signals that regulate the heartbeat ( conduction abnormalities ...
MedlinePLUS
depression in the generation of spontaneous activity in the chick embryo spinal cord. In: Neuronal mechanismsSpontaneous Network Activity Transiently Depresses Synaptic Transmission in the Embryonic Chick of spontaneous or evoked episodes of rhythmic activity on synaptic transmission in several spinal pathways
of glutamate synapses by nicotinic acetylcholine receptors in auditory cortex. Neurobiol. Learn. Mem., 80, 285Nicotinic modulation of glutamatergic synaptic transmission in region CA3 of the hippocampus Lisa M, hippocampus, memory, nicotine Abstract Cholinergic modulation of synaptic transmission in the hippocampus
Adenosine Released by Astrocytes Contributes to Hypoxia-Induced Modulation of Synaptic Transmission of excitatory synaptic transmission me- diated by activation of presynaptic A1 adenosine receptors. The glia-specific metabolic inhibitor fluorocitrate (FC) was as effective as the A1 adenosine receptor antagonist ...
Congenital deafness results in synaptic abnormalities in auditory nerve endings. These abnormalities are most prominent in terminals called endbulbs of Held, which are large, axosomatic synaptic endings whose size and evolutionary conservation emphasize their importance. Transmission jitter, ...
Chemically and electrically mediated synaptic transmission are compared with respect to a number of properties; nonlinearity, linearity, amplification, delay, inhibition, reciprocity, irreciprocity, temporal summation, facilitation, and defacilitation. Mo...
SHANK3 is a synaptic scaffolding protein enriched in the postsynaptic density (PSD) of excitatory synapses. Small microdeletions and point mutations in SHANK3 have been identified in a small subgroup of individuals with autism spectrum disorder (ASD) and intellectual disability. SHANK3 also plays a key role in the chromosome 22q13.3 microdeletion syndrome (Phelan-McDermid ...
Experiences, whether they be learning in a classroom, a stressful event, or ingestion of a psychoactive substance, impact the brain by modifying the activity and organization of specific neural circuitry. A major mechanism by which the neural activity generated by an experience modifies brain function is via modifications of synaptic transmission; that is, ...
Processes of synaptic plasticity, such as long-term potentiation (LTP), has been considered a cellular correlate of learning and memory and many neurological disorders accompanied by cognitive deficits exhibit abnormal synaptic function. This emerging concept is exemplified by Alzheimer's disease. Mounting evidence suggests that ...
Microtubules function as molecular tracks along which motor proteins transport a variety of cargo to discrete destinations within the cell. The carboxyl termini of ?- and ?-tubulin can undergo different posttranslational modifications, including polyglutamylation, which is particularly abundant within the mammalian nervous system. Thus, this modification could serve as a molecular �traffic ...
Synaptic activity mediated via GABA receptors in thalamic circuits is critically involved in the generation of hypersynchrony associated with absence epilepsy. Neurons of "unspecific" intralaminar thalamic nuclei display characteristic burst patterns during seizure activity, although their synaptic properties remain largely unknown. Here, we used in vitro ...
Accumulation of ?-amyloid (A?) and loss of synapses are hallmarks of Alzheimer�s disease (AD). How synaptic activity relates to A? accumulation and loss of synapses is a current topic of major interest. Synaptic activation promotes A? secretion, and chronic reduction of synaptic activity reduced A? plaques in an AD transgenic mouse ...
The medial nucleus of the trapezoid body (MNTB) receives excitatory input from giant presynaptic terminals, the calyces of Held. The MNTB functions as a sign inverter giving inhibitory input to the lateral and medial superior olive, where its input is important in the generation of binaural sensitivity to cues for sound localization. Extracellular recordings from MNTB neurons show complex spikes ...
Astrocytes dynamically interact with neurons to regulate synaptic transmission. Although the gap junction proteins connexin 30 (Cx30) and connexin 43 (Cx43) mediate the extensive network organization of astrocytes, their role in synaptic physiology is unknown. Here we show, by inactivating Cx30 and Cx43 genes, that astroglial networks ...
Mar 1, 2011 ... 2001), a pathological hal1nark of Alzheimer's disease. Abnormal phosphorylaion of synapsin I has been linked to alterations in synaptic ...
NASA Website
2001), a pathological hal1nark of Alzheimer's disease. Abnormal phosphorylaion of synapsin I has been linked to alterations in synaptic vesicle trafficking ...
DYT1 dystonia is a severe form of inherited dystonia, characterized by involuntary twisting movements and abnormal postures. It is linked to a deletion in the dyt1 gene, resulting in a mutated form of the protein torsinA. The penetrance for dystonia is incomplete, but both clinically affected and non-manifesting carriers of the DYT1 mutation exhibit impaired motor learning and ...
BackgroundMyosin VI, encoded by jaguar (jar) in Drosophila melanogaster, is a unique member of the myosin superfamily of actin-based motor proteins. Myosin VI is the only myosin known to move towards the minus or pointed ends of actin filaments. Although Myosin VI has been implicated in numerous cellular processes as both an anchor and a transporter, little is known about the role of Myosin VI in ...
Inter-pyramidal synaptic connections are characterized by a wide range of EPSP amplitudes. Although repeatedly observed at different brain regions and across layers, little is known about the synaptic characteristics that contribute to this wide range. In particular, the range could potentially be accounted for by differences in all three parameters of the ...
To study regulation in vivo of the promoter for the neural cell adhesion molecule, N-CAM, we have used homologous recombination to insert the bacterial lacZ gene between the transcription and translation initiation sites of the N-CAM gene. This insertion disrupts the gene and places the expression of ?-galactosidase under the control of the N-CAM promoter. Animals homozygous for the disrupted ...
Alzheimer's disease (AD) is the most common cause of dementia in aging populations. Although amyloid plaques are the hallmark of AD, loss of synapses and synaptic dysfunction are closely associated with the duration and severity of cognitive impairment in AD patients. Amyloid precursor protein (APP) and its cleavage products including A? have been suggested as homeostatic ...
Selective receptor antagonists are one of the most powerful resources in a pharmacologist's toolkit and are essential for the identification and classification of receptor subtypes and dissecting their roles in normal and abnormal body function. However, when the actions of antagonists are measured inappropriately and misleading results are reported, confusion and wrong ...
An edited summary of an Interdepartmental Conference arranged by the Department of Medicine of the UCLA School of Medicine, Los Angeles. The Director of Conferences is William M. Pardridge, MD, Associate Professor of Medicine. Current findings indicate that autoimmune myasthenia gravis is an acquired immune complex disorder of neuromuscular transmission in voluntary striated ...
Glutamate excites receptors located on neurons that cause calcium and sodium influx involved in excitatory synaptic transmission. During ischemia, excess glutamate is present in the extracellular space of brain tissue, leading to abnormal levels of calcium influx and eventually to cell death. In mixed neuronal/glial cell cultures we ...
