Stress and Anxiety. Dogs are sensitive animals; excessive stress or anxiety in their lives can cause hair loss. Sometimes hair loss is a bodily physical manifestation of stress, but other times anxious dogs will partake in compulsive licking that leads to hair loss in areas they lick too much. Dogs may get stressed or anxious due to a number of reasons, including confinement, bullying from other pets in the house, separation anxiety and past trauma or abuse.
Confidence votes 1.2K. Sodium. A positive ion (cation) that enters the cell (influx) rapidly when the membrane threshold is reached and the voltage gated sodium channels open. This occurs during the rising phase of an action potential, i.e. membrane depolarization beyond the threshold for activation.
A stimulus from a sensory cell or another neuron depolarizes the target neuron to its threshold potential (-55 mV), and Na+ channels in the axon hillock open, starting an action potential. Once the sodium channels open, the neuron completely depolarizes to a membrane potential of about +40 mV.