Pathways and polarities of synaptic interactions in the inner retina of the mudpuppy: I. Synaptic blocking studies.
Intracellular recording techniques were applied to the perfused retina-eyecup of the mudpuppy (Necturus maculosus). The use of input resistance measurements and the application of cobalt as a synaptic blocking agent provided evidence about the mode of synaptic operation for depolarizing and hyperpolarizing bipolar cell input to cells of the inner retina. In addition, cobalt produced a more rapid block of hyperpolarizing bipolars compared to depolarizing bipolars; in some postbipolar neurons, a temporary simplification of neuronal response waveform was observed and such cells resembled the depolarizing bipolar. These experiments suggest that bipolar cell input is excitatory and that response characteristics of third-order neurons is partially dependent on the relative input from the two types of bipolar cells.
D000818:Animals; D002712:Chlorides / Q000494:pharmacology; D003035:Cobalt / Q000494:pharmacology*; D003623:Dark Adaptation / Q000187:drug effects; D005071:Evoked Potentials / Q000187:drug effects; D009474:Neurons / Q000502:physiology; D010775:Photic Stimulation; D010786:Photoreceptor Cells / Q000502:physiology; D012160:Retina / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects*; D014562:Caudata; D014795:Visual Pathways / Q000187:drug effects / Q000502:physiology
D002712:Chlorides; D003035:Cobalt