scholarly journals Antagonism of D 1/ D 5 receptors prevents long‐term depression ( LTD ) and learning‐facilitated LTD at the perforant path–dentate gyrus synapse in freely behaving rats

Hippocampus ◽  
2014 ◽  
Vol 24 (12) ◽  
pp. 1615-1622 ◽  
Author(s):  
Valentina Wiescholleck ◽  
Denise Manahan‐Vaughan
Keyword(s):  
Dentate Gyrus ◽  
Perforant Path ◽  
Long Term Depression ◽  
Freely Behaving

In Vivo Recordings of Long-Term Potentiation and Long-Term Depression in the Dentate Gyrus of the Neonatal Rat

2004 ◽  
Vol 91 (2) ◽  
pp. 613-622 ◽  
Author(s):  
Michael P. O'Boyle ◽  
Viet Do ◽  
Brian E. Derrick ◽  
Brenda J. Claiborne
Keyword(s):  
Dentate Gyrus ◽  
Granule Cells ◽  
Long Term Potentiation ◽  
Neonatal Rat ◽  
Perforant Path ◽  
Long Term Depression ◽  
Term Potentiation ◽  
Old Rats

Previous in vitro studies demonstrated that long-term potentiation (LTP) could be elicited at medial perforant path (MPP) synapses onto hippocampal granule cells in slices from 7-day-old rats. In contrast, in vivo studies suggested that LTP at perforant path synapses could not be induced until at least days 9 or 10 and then in only a small percentage of animals. Because several characteristics of the oldest granule cells are adult-like on day 7, we re-examined the possibility of eliciting LTP in 7-day-old rats in vivo. We also recorded from 8- and 9-day-old rats to further elucidate the occurrence and magnitude of LTP in neonates. With halothane anesthesia, all animals in each age group exhibited synaptic plasticity of the excitatory postsynaptic potential following high-frequency stimulation of the MPP. In 7-day-old rats, LTP was elicited in 40% of the animals and had an average magnitude of 143%. Long-term depression (LTD) alone (magnitude of 84%) was induced in 40% of the animals, while short-term potentiation (STP) alone (magnitude of 123%) was induced in 10%. STP followed by LTD was elicited in the remaining 10%. Data were similar for all ages combined. In addition, the N-methyl-d-aspartate (NMDA) antagonist ( R,S)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP) blocked the occurrence of LTP at each age and doubled the percentage of animals expressing LTD alone for all ages combined. These results demonstrate that tetanic stimulation can elicit LTP or LTD at MPP synapses in 7-day-old rats, supporting our premise that at least a portion of the dentate gyrus is functional at this early age.

scholarly journals Endocannabinoid long-term depression revealed at medial perforant path excitatory synapses in the dentate gyrus

2019 ◽  
Vol 153 ◽  
pp. 32-40 ◽  
Author(s):  
Sara Peñasco ◽  
Irantzu Rico-Barrio ◽  
Nagore Puente ◽  
Sonia María Gómez-Urquijo ◽  
Christine J. Fontaine ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Perforant Path ◽  
Excitatory Synapses ◽  
Long Term Depression

Evidence for common expression mechanisms underlying heterosynaptic and associative long-term depression in the dentate gyrus

1995 ◽  
Vol 74 (3) ◽  
pp. 1244-1247 ◽  
Author(s):  
B. R. Christie ◽  
D. Stellwagen ◽  
W. C. Abraham
Keyword(s):  
Dentate Gyrus ◽  
High Frequency ◽  
Granule Cells ◽  
Perforant Path ◽  
Long Term Depression ◽  
Anesthetized Rats ◽  
Data Support ◽  
Activity Dependent ◽  
Stimulation Of

1. The extent to which heterosynaptic and prime-associative stimulation protocols generate different forms of long-term depression (LTD) was assessed in the lateral perforant path synapses terminating on dentate gyrus granule cells in pentobarbital-anesthetized rats. 2. Heterosynaptic LTD was induced in the lateral path by repeated tetanization of the medial path. Prime-associative LTD of the lateral path was induced by alternating high-frequency conditioning trains to the medial path and single shocks to the lateral path at 100-ms intervals, all occurring 10 min after priming stimulation of the lateral path (5 Hz, 80 pulses). 3. Induction of LTD by one administration of the prime-associative protocol was normally greater in magnitude than the LTD induced by the heterosynaptic protocol. Saturation of LTD by repeated delivery of the prime-associative protocol completely occluded the subsequent induction of LTD by the heterosynaptic protocol. Saturation of LTD by repeated delivery of the heterosynaptic protocol produced an 80% occlusion of the LTD generated by the prime-associative protocol. 4. These data support the hypothesis that activity-dependent (associative) and activity-independent (heterosynaptic) LTD involve overlapping expression mechanisms, despite having demonstrably different induction mechanisms.

scholarly journals Endocannabinoid receptors contribute significantly to multiple forms of long-term depression in the rat dentate gyrus

2020 ◽  
Vol 27 (9) ◽  
pp. 380-389
Author(s):  
Christine J. Fontaine ◽  
Erin L. Gräfe ◽  
Cristina Pinar ◽  
Itziar Bonilla-Del Río ◽  
Pedro Grandes ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Cannabinoid Receptors ◽  
Hippocampal Formation ◽  
Low Frequency ◽  
Perforant Path ◽  
Sprague Dawley ◽  
Long Term Depression ◽  
Group I ◽  
Frequency Stimulation

Cannabinoid receptors are widely expressed throughout the hippocampal formation, but are particularly dense in the dentate gyrus (DG) subregion. We, and others, have shown in mice that cannabinoid type 1 receptors (CB1Rs) are involved in a long-term depression (LTD) that can be induced by prolonged 10 Hz stimulation of the medial perforant path (MPP)-granule cell synaptic input to the DG. Here, we extend this work to examine the involvement of CB1Rs in other common forms of LTD in the hippocampus of juvenile male and female Sprague–Dawley rats (Rattus norvegicus). We found, as in mice, that prolonged 10 Hz stimulation (6000 pulses) could reliably induce a form of LTD that was dependent upon CB1R activation. In addition, we also discovered a role for both CB1R and mGluR proteins in LTD induced with 1 Hz low-frequency stimulation (1 Hz-LTD; 900 pulses) and in LTD induced by bath application of the group I mGluR agonist (RS)-3,5-Dihydroxyphenylglycine (DHPG; DHPG-LTD). This study elucidates an essential role for endocannabinoid receptors in a number of forms of LTD in the rat DG, and identifies a novel role for CB1Rs as potential therapeutic targets for conditions that involve impaired LTD in the DG.

Overexpression of βCaMKII impairs behavioral flexibility and NMDAR-dependent long-term depression in the dentate gyrus

2017 ◽  
Vol 116 ◽  
pp. 270-287 ◽  
Author(s):  
Pengcheng Yin ◽  
Hao Xu ◽  
Qi Wang ◽  
Jiayue Wang ◽  
Liang Yin ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Behavioral Flexibility ◽  
Long Term Depression
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