Search results for "long-term potentiation"
showing 10 items of 101 documents
Specific Hippocampal Interneurons Shape Consolidation of Recognition Memory
2020
Summary A complex array of inhibitory interneurons tightly controls hippocampal activity, but how such diversity specifically affects memory processes is not well understood. We find that a small subclass of type 1 cannabinoid receptor (CB1R)-expressing hippocampal interneurons determines episodic-like memory consolidation by linking dopamine D1 receptor (D1R) signaling to GABAergic transmission. Mice lacking CB1Rs in D1-positive cells (D1-CB1-KO) display impairment in long-term, but not short-term, novel object recognition memory (NOR). Re-expression of CB1Rs in hippocampal D1R-positive cells rescues this NOR deficit. Learning induces an enhancement of in vivo hippocampal long-term potenti…
The K63 deubiquitinase CYLD modulates autism-like behaviors and hippocampal plasticity by regulating autophagy and mTOR signaling.
2021
Nondegradative ubiquitin chains attached to specific targets via Lysine 63 (K63) residues have emerged to play a fundamental role in synaptic function. The K63-specific deubiquitinase CYLD has been widely studied in immune cells and lately also in neurons. To better understand if CYLD plays a role in brain and synapse homeostasis, we analyzed the behavioral profile of CYLD-deficient mice. We found that the loss of CYLD results in major autism-like phenotypes including impaired social communication, increased repetitive behavior, and cognitive dysfunction. Furthermore, the absence of CYLD leads to a reduction in hippocampal network excitability, long-term potentiation, and pyramidal neuron s…
Mice lacking α-synuclein display functional deficits in the nigrostriatal dopamine system
2000
alpha-Synuclein (alpha-Syn) is a 14 kDa protein of unknown function that has been implicated in the pathophysiology of Parkinson's disease (PD). Here, we show that alpha-Syn-/- mice are viable and fertile, exhibit intact brain architecture, and possess a normal complement of dopaminergic cell bodies, fibers, and synapses. Nigrostriatal terminals of alpha-Syn-/- mice display a standard pattern of dopamine (DA) discharge and reuptake in response to simple electrical stimulation. However, they exhibit an increased release with paired stimuli that can be mimicked by elevated Ca2+. Concurrent with the altered DA release, alpha-Syn-/- mice display a reduction in striatal DA and an attenuation of …
Glia talk back.
2014
This study shows that the activity of neurons can trigger shedding of a protein, NG2, from the surface of oligodendrocyte precursor cells; this protein in turn modulates synaptic transmission, revealing a two-way conversation between neurons and glia.
BDNF contributes to the facilitation of hippocampal synaptic plasticity and learning enabled by environmental enrichment
2014
Sensory, motor, and cognitive stimuli, resulting from interactions with the environment, play a key role in optimizing and modifying the neuronal circuitry required for normal brain function. An experimental animal model for this phenomenon comprises environmental enrichment (EE) in rodents. EE causes profound changes in neuronal and signaling levels of excitation and plasticity throughout the entire central nervous system and the hippocampus is particularly affected. The mechanisms underlying these changes are not yet fully understood. As brain-derived neurotrophic factor (BDNF) supports hippocampal long-term potentiation (LTP), we explored whether it participates in the facilitation of sy…
Acute effects of antidepressant drugs on long-term potentiation (LTP) in rat hippocampal slices.
1991
The actions of three clinically effective antidepressant drugs with different pharmacological profiles were investigated in the CA1 area of rat hippocampal slices. Imipramine and (+) or (-)-oxaprotiline had negligible effects on population spikes evoked by stratum radiatum stimulation, but reduced postsynaptic excitability in low Ca high Mg medium after an exposure of more than 15 min. Imipramine and (+)-oxaprotiline at 10 mumol/l enhanced long-term potentiation (LTP) when a lower stimulation strength was applied while (+)-oxaprotiline reduced LTP when a higher stimulus amplitude was used to evoke population spikes. (-)-oxaprotiline (levoprotiline) had a similar effect which was, however, n…
A repetitive intracortical microstimulation pattern induces long-lasting synaptic depression in brain slices of the rat primary somatosensory cortex.
2000
Repetitive intracortical microstimulation (ICMS) applied to the rat primary somatosensory cortex (SI) in vivo was reported to induce reorganization of receptive fields and cortical maps. The present study was designed to exam- ine the effect of such an ICMS pattern applied to layer IV of brain slices containing SI on the efficacy of synaptic in- put to layer II/III. Effects of ICMS on the synaptic strength was quantified for the first synaptic component ( s1) of cor- tical field potentials (FPs) recorded from layer II/III of SI. FPs were evoked by stimulation in layer IV. The pattern of ICMS was identical to that used in vivo. However, stimula- tion intensity had to be raised to induce an a…
The superoxide anion is involved in the induction of long-term potentiation in the rat somatosensory cortex in vitro.
2004
Abstract The involvement of the superoxide anion (O2−) in the induction of neocortical long-term potentiation (LTP) was examined in rat brain slices containing the primary somatosensory cortex. Field potentials evoked by stimulation in cortical layer IV were recorded from layer II/III. In control experiments, tetanic high-frequency stimulation (HFS) resulted in essentially input-specific, NMDA receptor-dependent LTP (20.2±3.0% increase in field potential amplitude). When the availability of intracellular O2− was reduced by application of the cell membrane-permeable O2− scavengers MnTBAP or CP-H (spin trap), HFS-induced LTP was attenuated to 12.0±1.7% and 8.7±3.1% increase, respectively. In …
Role of the amygdala in antidepressant effects on hippocampal cell proliferation and survival and on depression-like behavior in the rat
2021
The stimulation of adult hippocampal neurogenesis by antidepressants has been associated with multiple molecular pathways, but the potential influence exerted by other brain areas has received much less attention. The basolateral complex of the amygdala (BLA), a region involved in anxiety and a site of action of antidepressants, has been implicated in both basal and stress-induced changes in neural plasticity in the dentate gyrus. We investigated here whether the BLA modulates the effects of the SSRI antidepressant fluoxetine on hippocampal cell proliferation and survival in relation to a behavioral index of depression-like behavior (forced swim test). We used a lesion approach targeting th…
Anticonvulsants do not suppress long-term potentiation (LTP) in the rat hippocampus
1991
Long-term potentiation (LTP) of population spikes in the CA1 area of rat hippocampus was induced by tetanic stimulation of stratum radiatum in slices kept submerged in a perfusion chamber. Addition of the two antiepileptic drugs phenytoin or the diazepine midazolam to the medium did not significantly alter this phenomenon within 22 min after the tetanus. The early enhancement (post-tetanic potentiation, PTP) was reduced only by phenytoin. Therefore an interaction of these drugs with N-methyl-D-aspartate (NMDA) receptors and LTP induction is unlikely.