α-Bungarotoxin receptors in the CNS

This chapter discusses α-Bungarotoxin (BuTX) receptors in the central nervous system (CNS). The chapter discusses the regulation of BuTX binding sites by cholinergic drugs. The relationship between the concentration of BuTX binding sites and the effect of nicotine on behaviors that are believed to be mediated by nicotinic cholinergic receptors is investigated. In doses that produce the up-regulation of toxin binding, nicotine administered via osmotic mini pumps results in a transient increase in behavioral activity as measured by telemetry. Some of the effect of nicotine demonstrated relates to the absence of a depression in activity following surgery, which probably reflects the ability of nicotine to reverse the depressant effect of anesthesia. The effects of AF64 on the circadian rhythm and nAChRs are discussed. Studies of physiological and behavioral characteristics under the control of the hypothalamus, however, may eventually lead to more promising results. The hypothalamus is associated with a wide variety of endocrine and homeostatic functions, many of which are believed to be mediated by nicotinic receptors. The hypothalamus is rich in BuTX binding sites and may make a good model to study the function of the BuTX binding protein.