Fig. 3.

Intracellular synaptic response in a CA1 pyramidal neuron from an NPY^−/− mouse. A, Representative intracellular recording from a CA1 pyramidal neuron (resting membrane potential = −64 mV) during Schaffer collateral stimulation. Note the presence of an EPSP followed by a biphasic IPSP with fast (closed circle) and slow (open circle) components. B, Reversal potential plot of the fast and slow IPSPs for this CA1 pyramidal neuron. Reversal potentials were determined by systematically changing the membrane potential via intrasomatic current injection, evoking IPSPs at a stimulation intensity subthreshold for generation of an action potential and measuring the amplitude and polarity of the resulting IPSP at the time points indicated in A(open and closed circles). Vm, Membrane voltage. C, Intracellular response to paired-pulse stimulation of the Schaffer collaterals for this CA1 pyramidal neuron. Note the presence of paired-pulse facilitation of the EPSP at interpulse intervals between 15 and 65 msec.