physiology and pharmacology experiments
in virtual laboratories
almost like in the real world
- Perfect for online teaching and remote learning -
SimHeart and SimVessel feature physiological and pharmacological experi-ments with the isolated, perfused heart in the Langendorff-setup and with isolated smooth muscle strips of blood vessels (aorta) and the stomach (antrum) to examine the muscle contractions after application of physiolo-gical transmitters (Acetylcholine), hormones (Adrenaline) and diverse drugs like the competitive receptor antagonists (Atropine, Phentolamine, Propranolol) and non-competitive modulators of Ca2+-currents and Ca2+-concentrations (Verapamil, g-Strophantin). An additional “Drug Laboratory” can be used practicing the correct preparation of the requested dilutions.
SimMuscle and SimNerv offer highly realistic experimental set-ups on the computer screen to record contractions of the frog’s gastrocnemic muscle (e.g. single twitches vs. tetanic contractions, muscle fatigue, curves of isometric and isotonic maxima) or compound action potentials from the frog’s sciatic nerve (dependence on electrode positions, refractory period, anode break potentials, etc.), respectively.
SimNeuron additionally allows performing widely used voltage- and current-clamp experiments in an easy to overlook lab design for recordings of current-voltage curves (reversal potentials etc.) or the threshold of action potential generation and its dependencies on stimulus strength and duration – also under application of TTX or TEA.
Although the virtual laboratories have originally been considered as minor substitutes of experiments with animal preparations, it turned out that the virtual labs can have major didactic advantages:
- The students are doing the experiments without negative emotions from the killing of an animal and without the fear that they need to kill one more animal if they are making a mistake that destroys the preparation.
- Only in the virtual laboratories the students feel free to explore the reaction of the preparation on their own, including unconventional stimulation protocols.
- The students have the possibility studying the reactions of the virtual preparations without any time pressure - also on their computers at home.
- Technically more challenging experiments like voltage- and patch-clamp recordings, that are unfeasible to be physically carried out in students’ introductory courses, can be realized in silico with a user-friendly interface.
running on all Windows platforms,
from Win XP to Win 10, 32 bit as well as 64 bit versions
SimHeart and SimVessel also include .swf files to run on MacOS
(see Technical Specifications)
problems with Win 10?
a) concerning hidden task bars of the Virtual Physiology programs in the full screen mode
b) concerning strange sound effects (only in very recent Win 10 versions appearing).
SimHeart offers a virtual laboratory for recordings of heart contractions in the Langendorff set-up in response on the most relevant transmitters and drugs, including a drug laboratory for the adjustment of the appropriate solutions.
SimVessel offers a virtual laboratory for the examination of smooth muscle contractions of vessels and the intestine.
The experiments can be done with muscle stripes, placed in an organ bath to which physiologically relevant signal substances and widely used drugs can be added. Preparing the appropriate dilutions can be trained, as in SimHeart, in a drug laboratory.
The virtual “SimMuscle” laboratory contains two nerve-muscle preparations and all the apparatus that you will need for experimentation in a simplified but quite realistic form.
When entering the lab you first need to switch on all the devices (POWER buttons). Then drag one of two already prepared nerve-muscle preparations from the Petri-dish to hang it in the suspension apparatus. This includes a mechano-electrical converter transforming changes of either the muscle force or muscle length, selectable by a toggle switch, into an electric potential. You can pre-stretch the muscle hanging one or more weights in the loop at which the muscle is fixed.
Muscle contractions are induced by current pulses delivered from a stimulation apparatus to the electrodes on which the nerve is placed. Stimuli as well as muscle contractions are displayed on a dual beam storage oscilloscope, appropriately displayed with accordingly adjusted voltage amplification and time base (via the rotary switches) and zero lines. Single or double pulses as well as trains of stimuli of selectable amplitude and intervals can be applied.
The example shows muscle contractions, here changes of the muscle length, in response to different trains of voltage pulses inducing isolated twitches, incomplete and complete tetanic contractions depending on the intervals in which the pulses are applied.
In the “SimNerv” laboratory you will find a stimulator, an oscilloscope, a recording chamber and a Petri dish with two already prepared nerves.
For your measurements take one of the nerves by mouse click out of the Petri-dish and place it on the electrodes in the recording chamber. The position of the electrodes can be changed and the temperature of the recording chamber can be adjusted. You can set a nerve ligature (fully reversible) using the thread.
The stimulator delivers voltage pulses to the stimulation electrodes. The stimulus is simultaneously displayed at channel 1 of the oscilloscope via a separate cable..AMPLITUDE and DURATION of the stimulus pulses can be adjusted as well as the DELAY between the onsets of two successive stimuli when TWIN pulses shall be applied (MODE). The POLARITY switch allows to invert the direction of the current flow, INVERT corresponds to an exchange of the stimulus electrode positions.
The simple double-beam storage oscilloscope displays the stimulus pulse (channel 1), simultaneously with the compound action potential (CAP, channel 2) measured as the potential difference between the two recording electrodes by means of a differential amplifier. The sensitivity of both oscilloscope channels (mV/DIV) as well as their common time-base (ms/DIV) can be adjusted via the rotary switches.
SimNeuron offers virtual laboratories for voltage- and current-clamp experiments in an easy to overlook lab design
In fully licensed versions there is the possibility to select to which specific features of the program the students shall have access. This can be done in so-called pre-settings window which you can open from the labs via the SETTINGS button in the switch bank. In demo versions the pre-settings are fixed with most functions enabled.