Montoya DA, Pang K (2004) Modulation of late long-term potentiation in the hippocampus: Effect of cholinergic and GABAergic medial septal lesions. Neuroscience 2004 Abstracts 972.12. Society for Neuroscience, San Diego, CA.
Summary: Long Term Potentiation (LTP) is an endurable change in synaptic efficacy produced by brief repetitive stimulation of specific afferents and is a cellular model of long term memory. The duration of LTP can vary depending on the intensity fo the inducing tetanic stimulation, which reflects the different phases of LTP. Early phase LTP does not require protein synthesis, whereas late-phase LTP is dependent on protein synthesis. Modulating transmitter systems may also be important in the conversion of early-phase to late-phase LTP. In previous studies, stimulation of the medial septum (MS) converted an early-phase LTP to a late-phase LTP in the dentate gyrus. These results suggest that cholinergic or GABA septohippocampal neurons may be important in late-phase LTP. The present study will evaluate whether cholinergic or GABAergic septohippocampal neurons are important in the development of long-lasting LTP after MS stimulation. LTP will be assessed in urethane anesthetized rats with prior intraseptal saline, 192 IgG-saporin (SAP; 0.245 micrograms/microliter) or kainic acid KA; 0.5 microgram/microliter) treatment. 192 IgG-saporin selectively destroys cholinergic MS neurons, while kainic acid preferentially damages GABAergic septohippocampal neurons. In preliminary studies, 5 trains of perforant path stimulation (15 pulses at 400 Hz/train) produced a transient LTP of the dentate population spike in urethane anesthetized rats. In this preparation, LTP lasted for about 90 minutes. In future experiments, we will assess whether late-phase LTP develops in the urethane anesthetized rats with MS stimulation followed by perforant path stimulation trains. If this occurs, rats with cholinergic or GABAergic MS lesions will be evaluated.
Related Products: 192-IgG-SAP (Cat. #IT-01)