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Currents generated by depolarizing voltage pulses were recorded in neurons from the pyramidal cell layer of the CA1 region of rat or guinea pig hippocampus with single electrode voltage-clamp or tight-seal whole-cell voltage-clamp techniques. In neurons in situ in slices, and in dissociated neurons, subtraction of currents generated by identical(More)
Neurons were acutely dissociated from the CA1 region of hippocampal slices from guinea pigs. Whole-cell recording techniques were used to record and control membrane potential. When the electrode contained KF, the average resting potential was about -40 mV and action potentials in cells at -80 mV (current-clamped) had an amplitude greater than 100 mV. Cells(More)
Techniques for extracting small, single channel ion currents from background noise are described and tested. It is assumed that single channel currents are generated by a first-order, finite-state, discrete-time, Markov process to which is added 'white' background noise from the recording apparatus (electrode, amplifiers, etc). Given the observations and(More)
1. Action potentials recorded in the soma of R15 neurones in the abdominal ganglia of Aplysia juliana were not suppressed by selective inhibition of either Na or Ca conductance alone. It was necessary to block both conductances to suppress action potentials. 2. Membrane currents generated by step depolarizations of the soma consisted of early transient and(More)
1. The transient increase in secretion of quanta of acetylcholine (phasic secretion) produced by an action potential or brief depolarizing current pulse in mouse phrenic nerve terminals was examined. 2. Following an activating stimulus, there was a brief delay (minimum latency) followed by a sigmoidal increase in secretion which then decayed exponentially.(More)
1. Whole-cell patch-clamp recordings from freshly dissociated rat CA1 neurons revealed a large transient Na+ current (INa,T) and a smaller, inactivation-resistant persistent Na+ current (INa,P). Both currents could be blocked with TTX. 2. The average current densities of INa,T and INa,P in thirty cells were 111.0 +/- 9.62 and 0.87 +/- 0.13 pA pF-1,(More)
Spontaneous inhibitory postsynaptic currents (i.p.s.cs) were recorded in voltage-clamped CA1 neurones in rat hippocampal slices. The exponential decay of i.p.s.cs was prolonged by concentrations of sodium pentobarbitone as low as 50 microM. With concentrations up to 100 microM, there was no change in the amplitude or rise time of the currents but current(More)
1. Miniature end-plate currents were recorded at neuromuscular junctions of toads, either in voltage-clamped fibres or with extracellular electrodes. The two methods gave similar results. 2. Two types of m.e.p.c.s, differing in their growth times (50-300 musec and 0-5-5 msec) were found. The more frequent had the shorter growth times. 3. The decay of(More)
The chemical phosphatase butanedione monoxime (BDM) reversibly inhibited twitches and tetanic contractions in bundles of rat soleus fibres in a dose-dependent manner (2-20 mM) but had no effect on the amplitude or time course of action potentials. In addition, BDM reversibly reduced the amplitude of potassium contractures demonstrating a depressant effect(More)