Bevan, S., Chad, J.E., Hollowood, F.S. and Wise, J.C.M.
A system to provide control of stimulation and acquisition of ionic
currents in cell membranes [In: Proceedings of the physiological society p. 7].
Journal of Physiology: Proceedings of the Physiological Society, 377
Full text not available from this repository.
A program has been developed which controls the electrical stimulation of cell membranes with concurrent acquisition of the induced ionic currents. The software is written for a Cambridge Electronic Design (CED) type 1401 Intelligent Laboratory
Interface driven by a Sperry model 45 personal computer, which is highly compatible
with the IBM XT.
The CED 1401 is a sophisticated and flexible instrument that contains its own 6502 microprocessor and directly addressable 64 K memory, with up to 2 Mbytes of extra memory. Our software requires at least 0-25 Mbytes of this extra memory and uses (1) the digital-to-analogue (12-bit) capability to produce stimulus wave forms of programmable shape, (2) the analogue-to-digital converters (12 bit) to sample the
evoked responses and (3) the internal 1401 clocks to control the timing of this
stimulation and acquisition, and also to provide synchronization with other experimental
apparatus. These features and others may all be used concurrently.
The program is menu-driven; keyboard input is subject to extensive error trapping
and run-time interaction with the system is achieved by use of function keys. A
'spreadsheet' format is used to input the variables defining the stimulus wave forms
which can be stored on disk for subsequent use. Interactive control menus available
during the experiment permit rapid retrieval of these sets of variables to suit currentor
voltage-clamp experiments or to generate repetitive pulses which, for example,
may be used to test for seal formation between a patch electrode and the cell
A comprehensive range of sampling frequencies, up to 32 K conversions/s, are
selectable. 'Windows' of 512-2048 points may be used to store selected portions of
the evoked responses for subsequent display and analysis. Data with experimental
details may also be stored on disk.
The system was designed, developed and documented using the Jackson system
of program development (Jackson, 1975; Giddings, 1984) and uses Pascal as the
high-level language. This approach permits the program to be modified to meet the
needs of the experimenter while maintaining a strict regime of modular program
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