First spike latency of ON/OFF neurons in the optic tectum of pigeons

: Some shallow and middle optic tectum (OT) neurons have stable, asymmetric full-screen ON and OFF stimulus response properties, which makes them candidates for delay encoding. In this paper, we investigated the delay encoding mechanism for the neuronal clusters in the OT region of pigeons and determined the mechanism of delay coding in the OT region. By analyzing the responses of the neuron cluster under full-screen switch-on and switch-off stimulation, we found that the delay coding was widespread in the OT region where the ON/OFF stimulation time difference was 4-6 ms. Information theory analysis under grating stimulation and experiments based on single-neuron character reconstruction of neurons showed that OT neuron clusters use the first spike latency (FSL) for the rapid transfer of spatial structure information. Furthermore, 4 models were used to predict the first spike latency of these OT neurons. The best simulation results were obtained using an architecture where the ON and OFF paths of multiple retinal ganglion cells (RGCs) were integrated and summed, respectively.