Footnote 1

Since sense organ's  neurons are external/exposed  brain cells,  and  central nervous system's (CNS')  neurons  are internal  brain cells,  we  can conclude empirically that  if  certain  CNS'  brain cells  are  used  as  sensory  neuroreceptors, the  consciousnesses produced are originated too from  the  initial depolarization-repolarization (i.e. initial contact) of  the  sodium (Na+) ions &  chloride (Cl-) ions  or sodium ions & inorganic phosphate (IP)  ions  or  potassium (K+) ions  & inorganic phosphate (IP)  ions  in the  neurons after  the neurotransmitter  attaches  on the membrane  receptors.  Sensory  neurons of the sense organs are external  portion  or extension  of the brain and, in some aspects, can represent brain cells.