Nerve impulses travel at speeds of up to 120 meters per second.
I'm not entirely certain that bit-rate is an appropriate term for the type of information processing that the nervous system is involved in.
Remember the "brain is a computer analogy" is just that, an analogy. In reality the brain is not a computer of the sort that you seem to be familar with.
For a start it is massively parallel. There is no Pentium bottleneck. Hence, there is no need for signals to be different because they do not terminate in the same place.
information flows through the nervous system like water flows down a river bed. It ends up in the place that it needs to because either that is the path that it has always traveled or that is the easiest path for it to flow.