Visual responses of nucleus isthmi in a teleost fish (Lepomis macrochirus).

摘要: Extracellular electrical activity was recorded from the nucleus isthmi of bluegill sunfish (Lepomis macrochirus) in response to brief flashes produced by red light emitting diodes, and other visual stimuli. Metal microelectrodes detected positive spikes outside nucleus, negative inside. Spikes a continuous range amplitudes up 1 mV occurred bursts, spontaneously visually triggered. The highest amplitude were triggered appearance or movement stimuli throughout field contralateral eye. Smaller both fields. However, all spiking habituated with repeated stimulation one region field. Stimulating at 12 widely spaced positions within eye yielded no consistent differences numbers large evoked. Different penetrations around also gave uniform distributions spike numbers. Thus visuotopic organization evident. evoked partially inhibited competing stimulus presented ipsilateral