Strain-dependent and stress-induced changes in rat hippocampal cholinergic system.
The study demonstrates that in the hippocampus of inbred Wistar-Kyoto (WKY) rats [3H]choline uptake is 38% higher than in Brown-Norway (BN) rats. In contrast, the maximum binding capacity of [3H]quinuclidinylbenzilate (QNB) is 28% lower in WKY than in BN rats. After immobilization stress there is a reduction in [3H]choline accumulation which is more pronounced in WKY rats. Furthermore, maximal QNB binding after stress is increased only in WKY rats. Choline acetyltransferase activity, which was 83.5% higher in WKY rats, was not altered after stress in both strains. We conclude that: (1) choline accumulation is directly related to choline acetyltransferase activity in hippocampal synaptosomes; (2) maximum cholinergic muscarinic binding capacity is inversely related to the above two presynaptic activities and (3) immobilization stress results in a decreased choline accumulation and may lead to an increased QNB binding. The results imply that reduction in choline accumulation may be a compensatory mechanism of cholinergic synapses during adaptation to lengthly periods of neuronal activity.
D000818:Animals; D001692:Biological Transport; D002794:Choline / Q000378:metabolism*; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011950:Receptors, Cholinergic / Q000378:metabolism*; D011976:Receptors, Muscarinic / Q000378:metabolism*; D012149:Restraint, Physical; D013045:Species Specificity; D013312:Stress, Physiological / Q000378:metabolism*
D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D011813:Quinuclidinyl Benzilate; D002795:Choline O-Acetyltransferase; D002794:Choline