Figure 4.

Coordinated burst firing in rectal nerves during motor complexes after organ culture. A, Colonic EMG and rectal nerve recording showing ∼15 min of ongoing activity in an organ cultured preparation, including two motor complexes. The firing rates and spike shapes of four single units discriminated from the rectal nerve recording are shown. Most single units showed an increase in firing rate during motor complexes. B, A single motor complex, revealing burst firing behavior in the rectal nerve. Several units contributed to the burst firing behavior; their individual spike events are indicated below the nerve recording trace. C, The same event shown in B with an expanded timescale, showing in more detail the individual contributions to burst firing made by four single units. D, An individual burst corresponding to the event marked by an asterisk in C.