Brain region-specific and time-dependent decreases of Gαi2 in amygdala-kindled rats

✍ Scribed by J.-C. Cutz; P.P. Li; W.M. Burnham; J.J. Warsh

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 698 KB
• Volume: 22
• Category: Article
• ISSN: 0887-4476
• DOI: 10.1002/(sici)1098-2396(199603)22:3<226::aid-syn4>3.0.co;2-e

✦ Synopsis

Immunoreactivity levels of G protein a-subunits, Gas (45 and 52 kDa), Gql, and GLX,~, were determined in plasma membranes prepared from ipsilateral amygdala-pyriform cortex (AM/pC), contralateral AM/PC, dorsal hippocampus (DH), and ventral hippocampus (VH) in amygdala-kindled rats 24 h, 1 month, and 3 months after the last seizure. Relative to sham controls, immunoreactivity levels of Gcqo were significantly reduced in ipsilateral AM/pC and DH, with maximal decreases observed, respectively, a t 24 h (26% form control levels) and 1 month (18% from control levels) postseizure. No significant alterations in the levels of Gall or either of the Ga, isoforms were observed. The reduction in GCX,~ levels was, however, not accompanied by measurable changes in Gwmediated inhibition of adenylyl cyclase, as estimated by GppNHp modulation of forskolin-activated adenylyl cyclase activity. The present findings add support to the hypothesis that long-term changes in brain functioning following kindling may involve altered expression andlor function of components of the transmembrane signalling cascade, including G proteins.