Activation of the dentate gyrus by stimulation of the contralateral perforant pathway: Evoked potentials and long-term potentiation after ipsi- and contralateral induction

Hippocampus ◽  
2001 ◽  
Vol 11 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Manfred Krug ◽  
Rudolf Brödemann ◽  
Renate Matthies ◽  
Heinz Rüthrich ◽  
Maria Wagner
Keyword(s):  
Evoked Potentials ◽  
Dentate Gyrus ◽  
Long Term Potentiation ◽  
Perforant Pathway ◽  
Term Potentiation ◽  
Stimulation Of

Evoked potentials and long-term potentiation in the mouse dentate gyrus after stimulation of the entorhinal cortex

1982 ◽  
Vol 75 (1) ◽  
pp. 134-148 ◽  
Author(s):  
Kathy Payne ◽  
Charles J. Wilson ◽  
Stephen Young ◽  
Eva Fifkova ◽  
Philip M. Groves
Keyword(s):  
Evoked Potentials ◽  
Dentate Gyrus ◽  
Entorhinal Cortex ◽  
Long Term Potentiation ◽  
Term Potentiation ◽  
Stimulation Of

scholarly journals Intracerebroventricular injection of oxidant and antioxidant molecules affects long-term potentiation in urethane anaesthetized rats

2008 ◽  
pp. 269-273
Author(s):  
A Viggiano ◽  
E Viggiano ◽  
M Monda ◽  
A Viggiano ◽  
S Ascione ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Dentate Gyrus ◽  
Long Term Potentiation ◽  
Control Group ◽  
High Frequency Stimulation ◽  
Perforant Pathway ◽  
Term Potentiation ◽  
Stimulation Of

Production of superoxide anions in the incubation medium of hippocampal slices can induce long-term potentiation (LTP). Other reactive oxygen species (ROS) such as hydrogen peroxide are able to modulate LTP and are likely to be involved in aging mechanisms. The present study explored whether intracerebroventricular (ICV) injection of oxidant or antioxidant molecules could affect LTP in vivo. With this aim in mind, field excitatory post-synaptic potentials (fEPSPs) elicited by stimulation of the perforant pathway were recorded in the dentate gyrus of the hippocampal formation in urethane-anesthetized rats. N-acetyl-Lcysteine, hydrogen peroxide (H2O2) or hypoxanthine/xanthineoxidase solution (a superoxide producing system) were administrated by ICV injection. The control was represented by a group injected with saline ICV. Ten minutes after the injection, LTP was induced in the granule cells of the dentate gyrus by high frequency stimulation of the perforant pathway. Neither the H2O2 injection or the N-acetyl-L-cysteine injection caused any variation in the fEPSP at the 10-min post-injection time point, whereas the superoxide generating system caused a significant increase in the fEPSP. Moreover, at 60 min after tetanic stimulation, all treatments attenuated LTP compared with the control group. These results show that ICV administration of oxidant or antioxidant molecules can modulate LTP in vivo in the dentate gyrus. Particularly, a superoxide producing system can induce potentiation of the synaptic response. Interestingly, ICV injection of oxidants or antioxidants prevented a full expression of LTP compared to the saline injection.

Interaction between paired-pulse facilitation and long-term potentiation during the stimulation of the cannabinoid and vanilloid systems in the dentate gyrus

2016 ◽  
Vol 1643 ◽  
pp. 27-34 ◽  
Author(s):  
Lida Tahmasebi ◽  
Alireza Komaki ◽  
Ruhollah Karamian ◽  
Siamak Shahidi ◽  
Abdolrahman Sarihi ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Long Term Potentiation ◽  
Paired Pulse ◽  
Paired Pulse Facilitation ◽  
Term Potentiation ◽  
Stimulation Of

Low-frequency stimulation of the perforant path produces long-term potentiation in the dentate gyrus of unanesthetized rats

1983 ◽  
Vol 61 (10) ◽  
pp. 1156-1161 ◽  
Author(s):  
R. W. Skelton ◽  
J. J. Miller ◽  
A. G. Phillips
Keyword(s):  
Dentate Gyrus ◽  
Low Frequency ◽  
Long Term Potentiation ◽  
Perforant Path ◽  
High Frequency Stimulation ◽  
Synaptic Efficacy ◽  
Term Potentiation ◽  
Frequency Stimulation ◽  
Stimulation Of

Brief periods of high-frequency stimulation of hippocampal afferents produce long-term potentiation (LTP) of synaptic transmission, but the minimum frequency capable of inducing this alteration in synaptic efficacy has not been specified. The present study used the repeated measurement of input–output curves in the perforant path – dentate gyrus system of freely moving rats to monitor synaptic efficacy and found that stimulation at 0.2 Hz, but not 0.04 Hz produced LTP. These results suggest that the minimum stimulation frequency capable of producing LTP is lower than previously described. Possible reasons for the discrepancy between the present and previous findings are discussed, along with the implications of low-frequency potentiation.

Functional Organization of the Projection From Area 2 to Area 4γ in the Cat

1997 ◽  
Vol 77 (6) ◽  
pp. 3107-3114 ◽  
Author(s):  
Marcello A. Caria ◽  
Takeshi Kaneko ◽  
Akihisa Kimura ◽  
Hiroshi Asanuma
Keyword(s):  
Evoked Potentials ◽  
Motor Skills ◽  
Functional Organization ◽  
Receptive Fields ◽  
Long Term Potentiation ◽  
Graded Responses ◽  
Term Potentiation ◽  
Restricted Region ◽  
Stimulation Of

Caria, Marcello A., Takeshi Kaneko, Akihisa Kimura, and Hiroshi Asanuma. Functional organization of the projection from area 2 to area 4γ in the cat. J. Neurophysiol. 77: 3107–3114, 1997. It has been shown that tetanic stimulation of area 2 of the somatosensory cortex produces long-term potentiation in neurons in area 4γ, and this has been suggested as the basis of learning new motor skills. The purpose of this study was to further elucidate the characteristics of this projection by the use of evoked potentials in area 4γ elicited by intracortical microstimulation of area 2. The experiments were carried out in cats and the following results were obtained. 1) In six animals, stimulation of a given site in area 2 elicited evoked potentials in a restricted region of area 4γ, the size of which ranged from 1 to 1.5 mm2. These responses were labeled “localized responses.” The evoked potentials were recorded from the superficial layers of the cortex, and were positive monophasic in shape. 2) In 16 animals, stimulation of a given site in area 2 elicited a focal response that was surrounded by smaller positive and monophasic potentials of <50% amplitude that spread broadly over area 4γ. These responses were labeled “graded responses.” 3) The sites that produced focal evoked potentials in area 4γ extended along the direction of the radial fibers in area 2. These sites were defined as most effective segments (MESs). 4) The receptive fields of neurons along the MES in area 2 were similar to those of neurons recorded at the foci of the evoked potentials in area 4γ. The results demonstrate that some of the projections from area 2 to area 4γ are highly specific and that the somatosensory and motor areas that are connected by these specific projections receive functionally related peripheral input. These results are discussed in relation to possible mechanisms underlying motor learning.

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