Characterization of pinealectomy induced convulsions in the Mongolian gerbil (Meriones unguiculatus).

The Mongolian gerbil (Meriones unguiculatus) exhibits convulsions after pinealectomy (PX). Included in the convulsions are wild running, tonic-clonic activity, and occasionally death. This paper reports various parameters that influence the convulsions. Animals 60 and 90 days old have a shorter latency to onset of convulsions than do 30-day-old gerbils. Animals pinealectomized at the onset of light (0600) in an LD 14:10 photoperiod have a shorter latency to onset and greater number of convulsions than animals pinealectomized at other times. Modulation of the photoperiod to LD 20:4 and 4:20 does not affect the convulsions. Superior cervical ganglionectomy (SCGX) does not result in convulsions; subsequent PX of the SCGX animals does. Replacement of pineal extract does not prevent the convulsions. The PX induced convulsion in gerbils resembles the parathyroidectomy-pinealectomy induced convulsion in the rat in all aspects, but with a shorter latency to onset.