T-Space at The University of Toronto Libraries >
School of Graduate Studies - Theses >
Please use this identifier to cite or link to this item:
|Title: ||Potassium Changing from Pro- to Anti-convulsant in the Epileptic Juvenile Rat Hippocampus|
|Authors: ||Yu, Wilson Jonathan|
|Advisor: ||Carlen, Peter Louis|
|Issue Date: ||17-Feb-2010|
|Abstract: ||Elevations in extracellular potassium (K+e) accompany seizure-like events (SLEs), but elevated K+ may also participate in seizure cessation. The objective of this thesis was to investigate the possibility that K+ may undergo a pro- to anti-convulsant switch in the epileptic juvenile (postnatal day 17-21) rat hippocampus.
Field recordings were performed in the CA1 pyramidal layer. SLEs and primary afterdischarges (PADs) were induced with 0.25 mM Mg/5 mM K+ perfusion or tetanic stimulation of the Schaffer collaterals respectively. In these seizure models, elevating [K+]e beyond 7.5 mM showed anticonvulsant properties. The addition of ZD7288, a blocker of the hyperpolarization activated nonspecific cationic current (Ih) and allowed SLEs to continue even in elevated [K+]e. This suggests that [K+]e switches from being pro- to anti-convulsant, in part due to an elevated [K+]e-induced potentiation of Ih. Ih likely contributes to this anticonvulsant behavior by decreasing membrane resistance and subsequently attenuating summation of incoming EPSPs.|
|Appears in Collections:||Master|
Department of Physiology - Master theses
This item is licensed under a Creative Commons License
Items in T-Space are protected by copyright, with all rights reserved, unless otherwise indicated.