ch oline ▁re ceptor . ▁ ▁He ▁often ▁used ▁cells ▁from ▁the ▁electric ▁org ans ▁of ▁Elect roph orus ▁electric us ▁( comm only ▁known ▁as ▁the ▁electric ▁e el ) ▁and ▁the ▁Tor ped o ▁cal iforn ica ▁( comm only ▁known ▁as ▁the ▁Pacific ▁electric ▁ray ) ▁in ▁his ▁studies ▁as ▁these ▁cells ▁have ▁a ▁high ▁density ▁of ▁ac et yl ch oline ▁re cept ors ▁and ▁im itate ▁m amm al ian ▁cells . ▁ ▁Research ▁on ▁ac et yl ch oline ▁re cept ors ▁ ▁His ▁research ▁on ▁ac et yl ch oline ▁re cept ors ▁sp anned ▁the ▁length ▁of ▁his ▁whole ▁career .   ▁He ▁studied ▁the ▁mechan isms ▁of ▁these ▁re cept ors , ▁their ▁response ▁to ▁flux , ▁c oca ine , ▁ph ency cl id ine , ▁other ▁in hib itors , ▁and ▁their ▁changes ▁in ▁rate ▁and ▁equilibrium . ▁ ▁In ▁his ▁ 1 9 7 6 ▁publication ▁“ Function al ▁Ac et yl ch oline ▁Re ceptor - E lect rop lax ▁M emb rane ▁Mic ros acs ▁( V es icles ): ▁Pur ification ▁and ▁Character ization ,” ▁H ess ▁determ ines ▁the ▁util ization ▁of ▁functional ▁versus ▁non function al ▁mic ros acs ▁and ▁how ▁they ▁account ▁for ▁the ▁efficiency ▁differences ▁in ▁mus cle ▁and ▁n erve ▁cells .   ▁In ▁his ▁paper ▁“ Ac et yl ch oline - Re ceptor - M edi ated ▁I on ▁Fl ux ▁in ▁Elect rop lax ▁M emb rane ▁Mic ros acs