Locus coeruleus bursts induced by glutamate trigger delayed perforant path spike amplitude potentiation in the dentate gyrus

1992 ◽  
Vol 89 (3) ◽  
Author(s):  
CarolynW. Harley ◽  
SusanJ. Sara
Keyword(s):  
Dentate Gyrus ◽  
Locus Coeruleus ◽  
Perforant Path ◽  
Spike Amplitude

Noradrenergic modulation of neuronal transmission in the offspring of amphetamine-treated rats

1983 ◽  
Vol 61 (7) ◽  
pp. 766-769 ◽  
Author(s):  
Oscar A. Ramírez ◽  
Hugo F. Carrer
Keyword(s):  
Synaptic Transmission ◽  
Dentate Gyrus ◽  
Locus Coeruleus ◽  
Entorhinal Cortex ◽  
Perforant Path ◽  
Catecholamine Metabolism ◽  
Behavioral Alterations ◽  
Gyrus Dentatus ◽  
Neuronal Transmission ◽  
Noradrenergic Modulation

The model of noradrenergic modulation of synaptic transmission between the entorhinal cortex and dentate gyrus was used to investigate the function of catecholaminergic neurones in the offspring of rats injected with dl-amphetamine during pregnancy (0.5 mg∙kg−1∙day−1; s.c). A conditioning train of pulses applied to the locus coeruleus produces an increase in the amplitude of the population spike evoked in the granule layer of the gyrus dentatus by perforant path stimulation. Results show that, in the offspring of amphetamine-treated rats, the potentiating effect of locus coeruleus stimulation was two to three times greater than in control animals (151 ± 30 vs. 66 ± 20%; p < 0.05). This effect may be due to the changes in catecholamine metabolism and (or) catecholamine receptors observed in these animals and could help explain the behavioral alterations caused by amphetamine exposure in utero.

Increase in extracellular dopamine levels during clozapine-induced potentiation in the hippocampal dentate gyrus of chronically prepared rabbits

2008 ◽  
Vol 86 (5) ◽  
pp. 249-256 ◽  
Author(s):  
Takashi Kubota ◽  
Itsuki Jibiki ◽  
Akira Ishikawa ◽  
Tomomi Kawamura ◽  
Sonoko Kurokawa ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Nmda Receptor ◽  
Dentate Gyrus ◽  
Negative Symptoms ◽  
Clinical Effect ◽  
Perforant Path ◽  
Hippocampal Dentate Gyrus ◽  
Extracellular Dopamine ◽  
Stimulation Of ◽  
Synaptic Responses

We previously found that 20 mg/kg clozapine i.p. potentiated the excitatory synaptic responses elicited in the dentate gyrus by single electrical stimulation of the perforant path in chronically prepared rabbits. We called this phenomenon clozapine-induced potentiation and proved that it was an NMDA receptor-mediated event. This potentiation is presumably related to clozapine’s clinical effect on negative symptoms and cognitive dysfunctions in schizophrenia. In the present study, to investigate the mechanisms underlying clozapine-induced potentiation, we examined whether extracellular dopamine and 5-HT levels changed during the potentiation by using a microdialysis technique in the dentate gyrus. The extracellular concentrations of dopamine and 5-HT levels were measured every 5 min during all experiments. Extracellular 5-HT levels did not change, but dopamine levels eventually increased significantly during clozapine-induced potentiation. The increase in the dopamine levels occurred almost simultaneously with the induction of clozapine-induced potentiation. These results suggest that clozapine-induced potentiation is at least partly attributable to a dopamine-mediated potentiation of excitatory synaptic transmission. The present study implies that such phenomena occur also in the perforant path–dentate gyrus pathway.

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