Electrical kindling of the rat dorsal hippocampus induced significant changes in the binding of 125I-peptide YY to Y1 and Y2 subtypes of neuropeptide Y receptors and in their mRNA levels in the area dentata as assessed by quantitative receptor autoradiography and in situ hybridization histochemistry. Binding to Y1 receptor sites decreased by 50% (p <0.05) in the molecular layer of the stimulated dentate gyrus, 2 days after preconvulsive stage 2 and 1 week or 1 month after generalized stage 5 seizures compared with sham-stimulated rats. Binding to Y2 receptor sites increased bilaterally by 3687% (p <0.05) in the hilus at stage 2 and 1 week or 1 month after stage 5. No significant changes were observed after one after discharge or in the other hippocampal subfields or in the cortex. Y1 receptor mRNA signal decreased bilaterally by 50-64% (p <0.01) in the granule cell layer, 6 h but not 24 h after stages 2 and 5. The Y2 receptor mRNA signal was enhanced by 283% (p <0.01) in the fell layer 24 h after stage 2. At 6 and 24 h after stage 5, mRNA levels were increased both ipsilaterally (283-and 360%, respectively; p <0.01) and contralaterally (190 and 260%, respectively; p <0.05). No significant changes in level of either mRNA was found following one after discharge. These modifications, and the enhanced neuropeptide Y release previously shown in the hippocampus, suggest that kindling is associated with lasting changes in neuropeptide Y-mediated neurotransmission.
|Number of pages||8|
|Journal||Journal of Neurochemistry|
|Publication status||Published - Apr 1998|
- Dentate gyrus
- Mossy fibers
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience