The sheep terminal nerve: coexistence of LHRH- and AChE-containing neurons.

The intracranial course of the terminal nerve was studied in the sheep. Luteinizing hormone-releasing hormone (LHRH) immunohistochemistry and acetylcholinesterase (AChE) activity detected histochemically revealed the existence of a major bundle of neural fibers coursing along the anterior cerebral artery, from the olfactory tubercle to the olfactory bulbs, at the surface of which the fibers spread out in a dense plexus, before reaching the cribiform plate. There were ganglia along the nerve, which contained at least two separate populations of identified cells: one possessing AChE activity and the other presenting LHRH immunoreactivity.