The spontaneously hypertensive rat (SHR) and its progenitor strain, the Wistar-Kyoto (WKY) display marked differences in brain catecholamines and behavior. The behavioral differences are suggestive of alterations in hippocampal function and, in particular, the noradrenergic input to the hippocampus. To test these hypotheses we have analyzed the performance of the SHR and WKY in a spatial memory maze task that is specifie to hippocampal function and determined the kinetics of norepinephrine (NE) uptake in synaptosomal preparations of the hippocampus. We have found that WKYs exhibit an abnormally strong bias tendency in T-maze arm preference that influences the rate of acquisition and the final level of maze performance. We have also found differences in noradrenergic uptake in hippocampal synaptosomes. WKYs exhibit higher NE uptake rates and higher kinetic constants for NE uptake when compared with SHRs, suggesting that strain differences in noradrenergic function may contribute to the observed behavioral differences.
Bibliographical noteFunding Information:
We thank Marsha Hunt for her expert typing assistance. This work was supported by PHS grants HL24110 (DW/and MH36064 (EDH).
- Maze performance
- Norepinephrine uptake
- Strain differences