Generation of end-inhibition in striate neurons in rabbits.
Eighty-six rabbit striate neurons were tested with lateral microinjection of lidocaine, GABA or bicuculline. Seven of the neurons expressed different levels of end-inhibition. We examined these end-stopping units by injection of lidocaine or bicuculline in adjacent areas in order to determine if a lateral cortical mechanism is underlying end-inhibition in rabbits as it has been proposed in cats. Microinjection of lidocaine resulted in an attenuation of the end-inhibition strength. Application of bicuculline had the opposite effect; the end-inhibition was reinforced. We suggest that as observed in cats, in rabbits end-inhibition is mediated through horizontal cortical connections which implies a postsynaptic inhibitory input to the end-stopping cell.
Morin
C
C
Département de Sciences Biologiques, Université de Montréal, Canada.
Molotchnikoff
S
S
D000818:Animals; D001640:Bicuculline / Q000008:administration & dosage / Q000494:pharmacology*; D005071:Evoked Potentials / Q000187:drug effects; D008012:Lidocaine / Q000008:administration & dosage / Q000494:pharmacology*; D008845:Microinjections; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011817:Rabbits; D014793:Visual Cortex / Q000187:drug effects / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000008:administration & dosage / Q000494:pharmacology*
D005680:gamma-Aminobutyric Acid; D008012:Lidocaine; D001640:Bicuculline