Neurons evaluate both the amplitude and the meaning of signals

Neural Cell Behavior and Fuzzy Logic

“…It may be possible for neurons to evaluate the significance of the difference between the appearance of simple events, such as numbers of trials ended or not ended by punishment, etc. During habituation and classical conditioning, neurons can perform such an evaluation by a selective modulation of their excitability [1258,1259]. Nevertheless, we do not know whether each neuron evaluates the learning process separately, on the basis of its synaptic influx and transient regulation of the AP threshold, or whether this requires more neurons.…”

“…Control of excitability may serve, too, as the means for modulation of neuronal activity. Excitability usually increases [1258,1355] during augmentation of the biological importance of the signal during conditioning and decreases when it falls during habituation [1266,1267,641,1272] and during extinction of conditioned reflexes [1259]. During instrumental learning, excitability also changes, but in a complex manner [881,1270,1351].…”

“…The unselective form of excitable membrane plasticity cannot be the basis for the selectivity of neuronal reactions [48,818] and such unselective phenomenon might influence plasticity but cannot explain the main particularities of learning. Nevertheless, sometimes the specific, in relation to the input, modifications of threshold were described [1258,1259,291,414,997,1339], although there are different explanations for this non-standard phenomenon: the selective change in excitability looks like an unconventional result.…”

Protection from neuronal damage evoked by a motivational excitation is a driving force of intentional actions

“…There is a selective form of excitable membrane plasticity [352,356], in which a neuron may have different excitabilities corresponding to different signals (for example, conditioned and discriminated or habitual and novel). During classical conditioning, excitability is changed selectively and transiently within the response evoked by the conditioned stimulus and does not affect responses evoked by the discriminated stimulus, which is never paired with the punishment [354,355]. That is, the threshold within different responses may differ, such as the thresholds within responses to the conditioned and discriminated stimuli.…”

“…Shifts of the membrane potential during acquisition of classical conditioning are insignificant [7,148,354,355]. Depolarization of the membrane potential through the action of unconditioned stimuli action can affect ion homeostasis and disturb excitability, but is compensated via some unknown homeostatic process seen after a pause in conditioning (Fig.…”