A useful hand mnemonic to demonstrate ion channel gating.

The aim of this illumination is to introduce a simple method for visualization of ion channel gating. The students’ feedback about the usefulness of this dynamic representation for learning the different gating states is also reported. The gating of the ion channel is basically explained by functional molecular motions (16). These conformational changes in protein subunits control the permeability of the ion pore in the channel. At the molecular scale, the structurefunction properties of channel protein obey complex kinetics (2). The ion channel has multiple states that cause misconceptions during the explanation of gating. It is documented that the abstract thinking about molecular mechanisms is more difficult for students (15). Indeed, the instructor descriptions must be explicit and proportional to audience knowledge level and their learning goals. Obviously, just a textual explanation fails to provide concrete learning and deep understanding for students (14). Therefore, several approaches have been reported to improve learning, and diverse teaching tools, methods, and models are routinely used to describe different learning objects (1, 3, 5, 7–9). Figures or animations are useful for external representations of ion channels, although the complex nature of gating cannot be covered by them completely. However, a set of various visualization methods for the illustration of different aspects of gating may provide better understanding and may be able to correct misconceptions because they can be planned to have additive or accumulative effects. The benefits of a similar approach were reported for anatomy learning (12). External representations improve problem solving and integration of previous knowledge (11). They also may be used as a mnemonic. The word “mnemonic” is derived from “Mnemosyne,” the goddess of memory in Greek mythology. The lexical meaning of mnemonic is memory enhancing or something intended to assist the memory. Mnemonics function by associating the main information with some other cues and improve the brain memorization during storage and retrieval (6, 10). There are several types of auditory, visual, and kinesthetic mnemonics (13). One form of visual mnemonics is hand mnemonics (HM), a simple visualization that can provide better and more comprehensible learning. An example for HM is to form a three-perpendicular axis using the thumb, index, and middle fingers (Fig. 1). Indeed, this HM is widely used in physics to demonstrate the relationship between the magnetic field, electrical current, and electromotive force, which is known as Fleming’s rule. It is also used for taking the cross product of two vectors. Ion channels are the basis for many physiological mechanisms, such as synaptic transmission, muscle contraction, sensory transduction, and endocrine secretion, as well as many pharmacological interventions. In addition, resting membrane potential, action potential, and refractory period are directly dependent on ion channel behavior. Ion channel gating has its specific and sometimes confusing terminology, like reopening from inactive state, deactivation from open to closed state, and closed-state inactivation (4). It is even difficult for some students to understand the simpler order of opening, inactivation, recovery transitions, and closing states of voltage-gated ion channel (Fig. 2). Therefore, these students would prefer just to memorize, instead of understanding, the concepts of ion channel gating. For better understanding of the ion channel properties rather than memorizing them, the students were introduced to using the HM as a convenient external representation for teaching ion channel gating. This HM was a three-dimensional schematic visualization of ion channel protein in the open, closed, and inactive configuration. Different positions of thumb and fingers were dynamically used in this HM.