European Journal of Anaesthesiology



Original Article

Effects of repeated anaesthesia on central cholinergic function in the rat cerebral cortex


C. D. Hanning a1c1, A. Blokland a2, M. Johnson a3 and E. K. Perry a3
a1 Leicester General Hospital, Department of Anaesthesia, Leicester, UK
a2 Maastricht Brain & Behavior Institute, Faculty of Psychology, Maastricht University, Maastricht, The Netherlands
a3 Centre for Development in Clinical Brain Ageing, MRC Building, Newcastle General Hospital, Newcastle upon Tyne, UK

Article author query
hanning cd   [PubMed][Google Scholar] 
blokland a   [PubMed][Google Scholar] 
johnson m   [PubMed][Google Scholar] 
perry ek   [PubMed][Google Scholar] 

Summary

Background and objective: General anaesthesia may contribute to postoperative cognitive decline in the elderly. The aim was to determine the effects of repeated pentobarbital anaesthesia throughout life on central cholinergic function in the rat.

Methods: Young Lewis rats were randomly allocated to two groups. The anaesthesia group (n = 15) was anaesthetized with pentobarbital 20 mg kg−1 intraperitoneally at 6, 8.5, 11, 13.5, 16, 18.5, 21 and 23.5 months of age. The control group (n = 12) was treated identically, apart from the anaesthesia. At 26 months of age, the animals were killed and the brain dissected and stored for analysis. Central cholinergic function in the cortex and hippocampus was assessed by measuring [3H]-epibatidine and [125I]α-bungarotoxin binding to nicotinic receptors and choline acetyltransferase (ChAT) activity.

Results: Tissue from nine rats in the anaesthesia group and eight in the control group was available for analysis. There was a significant reduction in α-bungarotoxin binding in the anaesthetized compared with the control group in the superior cortex (P < 0.0002) and molecular cortex (P < 0.04). There were no significant differences between the groups for epibatidine binding or ChAT.

Conclusions: Repeated anaesthesia in rat reduces central nicotinic cholinergic binding in the cortex. The findings may have implications for postoperative cognitive function studies.

(Accepted March 2002)


Key Words: ANAESTHETICS, GENERAL; MEMORY DISORDERS; RECEPTORS, NEUROTRANSMITTER, receptors, cholinergic, nicotinic.

Correspondence:
c1 Correspondence to: Christopher Hanning, Department of Anaesthesia, Leicester General Hospital, Leicester, LE5 4PW, UK. E-mail: cdh4@le.ac.uk; Tel: +44 (0)116 258 4602; Fax: +44 (0)116 258 4611