Presenilin 1 Regulates [Ca²⁺]i and Mitochondria/ER Interaction in Cultured Rat Hippocampal Neurons

Figure 7

Paraquat (PQ) causes an increase in excitability of mPS1-transfected neurons. (a) Sample illustration of a current clamped neuron, responding to a slow current ramp lasting 12 seconds, from below resting potential to a depolarizing potential. The cell begins to discharge action potentials around -30 mV and continues to fire at gradually higher rate until return to resting potential. Spike threshold can be measured (arrowhead) as well as spike size and after potential. (b–d) Averages of resting membrane potential (b) input resistance (c) and spike thresholds (d), in mPS1 (m), mPS1 in the presence of PQ (mPQ), PS1 (p), and PS1 in the presence of PQ (pPQ). A large and highly significant change in spike threshold is obvious.

(a)

(b)

(c)

(d)