Changes in cholinergic markers following kainic acid lesion of the ventral globus pallidus in rat.
Choline acetyltransferase (CAT) and glutamate decarboxylase (GAD) activities and [3H] quinuclidinyl benzilate ([3H]QNB) binding were determined in the rat frontal cortex following damage to the basal forebrain cholinergic system. Pre- and postsynaptic changes in the cholinergic system with the passage of time were also studied. After a unilateral injection of kainic acid into the right ventral globus pallidus, the GAD levels remained unaffected, but the CAT levels decreased to 63.4% after 7 days. After 12 weeks, the CAT levels had returned to 87% of the control value. The Bmax of [3H]QNB binding for the muscarinic receptor was higher in the ipsilateral cortex up to 4 weeks. On the other hand, the KD value at 12 weeks was higher without a change in the Bmax of the [3H]QNB binding. These findings might indicate an ongoing compensatory receptor mechanism of denervation supersensitivity as a response to early changes in presynaptic cholinergic activity and the production of postsynaptic effect with presynaptic cholinergic damage over a long period of time.
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D001479:Basal Ganglia / Q000187:drug effects*; D001931:Brain Mapping; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D002799:Cholinergic Fibers / Q000187:drug effects*; D005917:Globus Pallidus / Q000187:drug effects*; D005968:Glutamate Decarboxylase / Q000378:metabolism; D007608:Kainic Acid / Q000494:pharmacology*; D008297:Male; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011950:Receptors, Cholinergic / Q000187:drug effects*; D011976:Receptors, Muscarinic / Q000187:drug effects; D013377:Substantia Innominata / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D005680:gamma-Aminobutyric Acid; D011813:Quinuclidinyl Benzilate; D002795:Choline O-Acetyltransferase; D005968:Glutamate Decarboxylase; D000109:Acetylcholine; D007608:Kainic Acid