Is binding to nicotinic acetylcholine and dopamine receptors related to working memory in rats?
Nicotinic acetylcholine (ACh) and dopamine (DA) receptor activation has been found to be important for working memory. The regional distribution of these receptors in the brain has been well characterized. However, the relationship of the region-specific nicotinic ACh and DA binding density to memory performance has not been well assessed. In the current studies the relationship of receptor binding and memory function was examined. Receptor binding and memory performance were assessed in rats in three types of conditions: 1) chronic nicotine and mecamylamine vs. vehicle infusion; 2) lesions of the fimbria-fornix or medial basalocortical projection vs. sham lesions; and 3) 2-year-old aged rats vs. 3-month-old young adult rats. Nicotinic ACh receptors were labeled by [3H]N-methyl-carbamylcholine ([3H]MCC), D1 receptors by [3H]SCH 23390, and D2 receptors by [125I]iodosulpiride. Working memory was assessed using the radial-arm maze and T-maze delayed spatial alternation tasks. Chronic nico
